- Top Benefits of Using Lime for Agricultural Crops
- Acidic Soil Problems
- What Is Agricultural Lime?
- Types of Lime for Agricultural Crops
- Reducing Acidity Levels in Soil
- How Lime Helps Crops Grow
- How Crops React to Lime
- Applying Lime to Agricultural Crops
- Benefits of Lime for Soil
- Investing in Future Crop Production
- Lime for Gardens
- Using Garden Lime for Healthy Plants
- Where Does Lime Come From?
- Understanding Garden Soil pH
- When to Apply Garden Lime
- Using Limestone for Gardening
- Can Plants Have a Lime Deficiency?
- Where Can I Buy Garden Lime?
- Soil Acidity
- Desirable Soil pH for Optimum Crop Production pH Range
- Factors Affecting Soil Acidity
- Nitrogen Fertilizers
- Subsoil Acidity
- Liming Soil Pays
- Liming Materials
- Calcitic Limestone
- Dolomitic Limestone
- Hydrated Lime
- Basic Slag
- Ground Oyster Shells
- Fluid Lime
- Pelletized Lime
- Use of Fluid Lime and Pelletized Lime
- Fineness of Grinding is Important in Selecting Liming Materials
- Efficiency Factors for Liming Materials
- Efficiency Factors: Timing, Placement and Frequency of Application
- Excess Alkalinity – Natural and Induced
- Correction of Excess Alkalinity by Soil Acidulation
- Facts about Soil Acidity and Lime (E1566)
- 1. What is lime?
- 2. What is soil acidity?
- 3. What is active soil acidity?
- 4. What is reserve acidity?
- 5. What is meant by neutralizing value (NV)?
- 6. What is calcium carbonate equivalent?
- 7. What are the neutralizing values for commonly used liming materials?
- 8. Is particle size of lime important?
- 9. Where can I get lime analyzed?
- 10. What is calcic limestone?
- 11. What is marl?
- 12. What is dolomitic limestone?
- 13. How much magnesium does dolomitic limestone contain?
- 14. When should I use dolomitic lime?
- 15. What is pelletized lime?
- 16. What are the materials called fluid lime, liquid lime or lime suspension?
- 17. Are liquid lime materials better than dry lime?
- 18. Are wood ashes good for liming?
- 19. What are the benefits of using lime?
- 20. Will liming pay?
- 21. How much lime should I apply?
- 22. How long will it take for lime to react with the soil and how long will it last?
- 23. What if my leased land needs lime?
- 24. Should I lime my soil to pH 6.0, 6.5 or 6.8?
- 25. Will fertilizer replace the need for lime?
- 26. Should I topdress lime on my established lawn?
- 27. Is there additional information available?
- Related Topic Areas
- Accessibility Questions:
- What Is Lime Used For?
- Key To A Better Lawn and Garden?
- Plant Preferences – Slightly Acid
- Best Levels of pH For Plant Nutrients?
- Amazing Activity in Soil
- Testing Cucumbers – Possible Kids Science Experiment For Adding Lime
- Types Of Lime For Gardens
- Adding Lime May Improve Soil Texture
Top 10 Liming Questions
- How long does it take for lime to work?
- How little or how much lime can be applied at one time?
- Should lime be worked into the soil or placed on the surface?
- Does liming have an effect on herbicide activity?
- What effect do different tillage systems have on soil pH?
- Are dolomitic sources of lime better than calcitic?
- What are the advantages and disadvantages of liquid lime verses dry lime?
- What is the cost effectiveness of liquid lime products versus agricultural lime?
- Why is the difference in soil pH and buffer pH on the soil test report?
- How often should I apply lime?
- Adding Lime To Soil: What Does Lime Do For Soil & How Much Lime Does Soil Need
- What Does Lime Do for Soil?
- How Much Lime Does Soil Need?
- How and When to Add Lime
Top Benefits of Using Lime for Agricultural Crops
Table of Contents
Agricultural Lime Products Find Your Local Distributor Get a Quote!
Growing agricultural crops is a complex line of work that requires a tremendous amount of expertise. Traditional agricultural crop growing faces all kinds of challenges in order to properly produce yields. Appropriate environmental conditions are critical to ensuring successful crops.
Soil quality is a critical component of successful crop growing. Crop health greatly depends on the balance of pH levels within the soil. When soil becomes too acidic – or has a lower pH level – it creates a toxic environment for crops. Acidic soil causes severe nutrient deficiencies for crops, which results in lower yields. Ultimately, this eats away at an agricultural business’s profits.
Fortunately, there is a way to monitor and remedy an acidic soil situation. When soil becomes acidic, it is a best practice to apply lime to the acidic soil where crops are grown as a way of raising pH levels and reducing acidity.
Acidic Soil Problems
One of the most important conditions for ensuring agricultural crops will grow is the condition of the soil, including the pH balance. When soil becomes too acidic, it can make it very difficult to maximize the yield of agricultural crops.
Acidity is measured on the pH scale whereby a pH level of seven is neutral. When soil pH levels drop below seven, it develops into a state of acidity. The more acidic the soil is, the more toxic it is for plants.
It is estimated that roughly 20 percent of North American farm fields are acidic and will need roughly two tons of agricultural lime per acre in order to supplement the acidity. A study by the Michigan State University reported that 25 percent of farm fields are at a pH level of below six.
The natural acidity of soil will differ from region to region. Some soils are sandy, some are more clay-like. This depends on climate and different properties of farmland regions. Additionally, the specific farming history of the piece of land in question may also determine acidity levels. Some lands may have been properly cared for and managed, while others may have been neglected. This could possibly lead to lower pH levels and an overall acidic soil environment.
What Is Agricultural Lime?
In order to counter the high acidity of the soil, certain soil amendments can be added to raise the pH levels and neutralize the acidic soil. Agricultural lime is the most effective soil amendment for raising pH levels in order to improve crop health and production.
Agricultural lime is a soil amendment product used to condition soil by raising pH levels. It is made from crushed limestone that contains natural nutrients to promote healthy plant growth. When lime is added to agricultural crops, it dissolves and releases a base that counteracts or neutralizes soil acidity.
Types of Lime for Agricultural Crops
Depending on how acidic the soil has become, there are different types of lime products to use. Lime is available as magnesium or calcium additives. Magnesium-based lime is called dolomitic lime. Calcium-based lime is called calcitic lime. Depending on your soil’s specific deficiency, it may require one type of lime or the other. It may even require a combination of both.
Agricultural lime comes in several states: oxides, hydroxide, silicate or carbonate. These are the forms of magnesium or calcium that will neutralize pH levels in the soil. Calcium and magnesium on their own will not neutralize the pH level. Only when they are applied in these forms will they serve the purpose of lowering acidity levels.
Reducing Acidity Levels in Soil
Soil naturally contains countless minerals and nutrients that each serve a purpose in helping crops grow healthily. When the mineral content becomes unbalanced, the soil can become too alkalized or too acidic depending on the levels of the different types of minerals.
When the soil contains high levels of minerals like iron, aluminum and manganese, then a pH imbalance is created. This causes soil acidity levels to rise. Simultaneously, this also causes a deficiency in other important soil minerals such as calcium and magnesium. Without calcium and magnesium, plants cannot reach healthy growth levels.
This pH imbalance can happen for any number of reasons. The soil itself could be naturally higher in these mineral contents, or it could be caused by the types of fertilizers being used. Alternatively, soil can become acidic when the presence of beneficial bacteria found in organic matter dwindles and there isn’t enough microbial activity in the soil. Whatever the case may be, acidic soil is generally a nutrient imbalance or deficiency that prevents healthy plant growth.
When soil becomes too acidic, it makes it very difficult for plant roots to grow. In fact, acidic soil can stunt root growth altogether, which prevents plant development. Plant roots aren’t able to take up nutrients effectively, which lowers the overall health level of the crops. In essence, high acidity creates a toxic environment for crops.
How Lime Helps Crops Grow
Agricultural lime helps lower the soil’s acidity levels by rendering it more pH neutral. By applying lime to the soil when it becomes too acidic, farmers can ensure they are helping improve their crop output. If crops can’t properly grow, they can’t produce, which impacts the agriculture business and its bottom line. This is why it becomes important to test your soil’s pH levels to determine the appropriate remedy as needed. Testing soil can help you determine where and when lime is needed, as well as how much.
In order to remedy the problem of acidic soil, lime can be applied to crops to raise the pH levels by adding in calcium and magnesium. Lime acts as a natural acid neutralizer for soil, which helps to reduce acidity and assist in returning the soil to a pH neutral status.
When soil is acidic, lime can help raise the pH levels, which improves many aspects of crop health. Agricultural lime comes in several forms that can neutralize the acidity in the soil. Lime is derived from magnesium or calcium carbonates, oxides, hydroxides or silicates. These substances help to neutralize the acidity in the soil and provide a thriving soil environment for crops to grow properly.
How Crops React to Lime
Different types of plants are more resistant to acidic soil than others. Certain types of plants can withstand the toxicity of acidic soil, while others will be much more susceptible and will not be able to withstand the toxicity. It’s important to understand each crop’s specific acidic tolerance before applying a lime solution.
When the right type of agricultural lime is appropriately applied to acidic soil, the crops that were once facing toxic conditions will begin to benefit from the change in pH levels. Plant roots will benefit from the calcium and/or magnesium supplementation. Roots will become more efficient at nutrient uptake. This will strengthen the overall root system and plant structure over time.
Agricultural lime products used on acidic soil have a natural varying size of particles. The plant roots can immediately absorb the smaller particles, as they are tiny enough for the roots to take up. The larger particles remain in the soil and continue to neutralize the soil’s acidity. The larger particles slowly break down over time into smaller particles. This helps to deliver a continuous supply of calcium and/or magnesium to the crops over a typical two to five-year period.
These improvements then go on to increase the crop’s ability to produce, which leads to greater yields and thus more profit for the farmer. Crops such as small grains, corn, Bermuda grass, soybeans and other legumes can greatly benefit from agricultural lime to improve yields.
Applying Lime to Agricultural Crops
Once the soil has been tested throughout the field, you can then determine the appropriate amount of lime to use. Certain sections of the soil may be more acidic than others. In this case, a suitable lime application plan must be created in order to avoid over- or undersupplying lime across the field.
Certain crop species may also have different lime amount requirements. Some crops may need only a slight decrease in acidity, whereas some would benefit from a much greater effort in balancing pH levels.
In many cases agricultural lime should be applied to the acidic areas of the soil at least six months prior to planting the next crop however the timing may be sooner or later depending on the agricultural lime’s particle sizing. Smaller particles with greater surface area tend to provide liming value and affect the pH more quickly than large particles do. If application should be applied at least six months prior to planting this means that lime should be applied after harvest in the late fall or winter months. By waiting six months, it gives the soil a sufficient amount of time to adjust to the added nutrients and balance out the pH levels.
When applying lime to agricultural crops, it’s important to work it into the soil as much as possible. If lime simply resides on the surface, it will take much longer for it to dissolve and then condition the soil. However, this may not apply to crops with roots that feed close to the surface, such as alfalfa, or if a no-till practice is being followed. If you are going to apply lime to your crops, it’s best to use crop-specific lime application practices.
Contact us for more information on applying limestone!
Benefits of Lime for Soil
There are several benefits of using lime for soil on certain crops as needed. These benefits ultimately lead to an improved yield in agricultural crops.
Here are the top benefits of using agricultural lime for crops:
- Reduces Levels of Manganese and Iron
By applying agricultural lime to crops, you can help to increase the soil’s pH level by neutralizing and reducing the levels of manganese and iron that cause soil to become acidic. Lower manganese and iron levels can help to reduce the risk of plants becoming toxic, which helps increase their growth and output rates.
- Boosts Microbial Activity
When soil is too acidic, the beneficial microbes in the soil aren’t able to thrive. This reduces soil health and the possibility of nutrient uptake in the crop’s roots. The agricultural lime effect on crops allows it to create a better environment to promote microbial activity to improve healthy crop growth.
- Improves Plant Structure
With a balanced pH level in the soil, the crop, especially young plants, can grow stronger overall. This additional strength starts in the roots and works its way up through the complete plant structure. Improved plant structure ensures the crops are healthier and able to yield more.
- Provides Calcium and Magnesium
Agricultural lime actively supplements calcium and/or magnesium levels in the soil. These are essential nutrients to ensuring healthy plant growth. Agricultural lime provides a steady supply of the nutrients, which over time ensures the soil is conditioned appropriately for optimum output.
- Provides a Return on Investment
When it comes to financial benefits, agricultural lime for crops is worth the investment. Agricultural lime is a long-term solution for ensuring maximum crop output. A single application of agricultural lime can last up to several years. During these years, your crops will produce better yields, which translates to more product and/or better product to sell.
- Increases Nutrient Uptake in Roots
Once the ag lime for crops is applied, it will begin to balance out the soil’s pH levels. A neutral or neutralized soil provides a healthy environment for plants to improve their nutrient uptake. When grown in acidic soil, plants struggle to take up nutrients. Once the soil becomes less acidic, the roots look for more nutrients to absorb.
- Strengthens Root System
As roots take up a greater volume of nutrients, they begin to thrive and strengthen throughout the whole root system. Having a strong root system in your crops is essential for the crop’s ability to withstand environmental challenges such as rain, wind or drought.
- Improves Nitrogen Fixation in Legumes
For legume crops like soybeans, agricultural lime can help improve nitrogen fixation. This is the process by which bacteria that live within the legume roots are able to convert atmospheric nitrogen into nutrients which crops can use.
- Improves Fertilizer/Herbicide Efficiency
When the soil becomes too acidic, it prevents herbicides from functioning properly. Acidic soil can also decrease fertilizer efficiency. By restoring soil to a more neutral pH level, it can help improve the efficiency of fertilizers and herbicides, which further improves your bottom line.
- Reduces Toxicity Levels
Ultimately, applying lime to agricultural crops will eliminate the state of toxicity that the plants are experiencing. Acidic soil is toxic for plants. Over time, acidic soil will kill crops. By neutralizing soil acidity while simultaneously providing adequate nutrition, you can move your crops from a toxic state to a thriving state.
Investing in Future Crop Production
While agricultural lime may seem at times like an expensive initial investment, the cost of the potential yield loss due to acidic soil conditions is far more costly than applying agricultural lime. Over time, agricultural lime can drastically improve soil conditions, leading to greater yields and greater profits.
Agricultural lime is a valuable investment that will see a return over time. It is important to get in the habit of applying lime to crops as needed in order to keep the pH levels stabilized. Otherwise, not having lime applied to crops when needed can perpetuate acidic conditions and reduce crop output. Agricultural lime should be an important consideration in any nutrient management plan.
If your soil is currently facing high levels of acidity, it’s important to invest in agricultural lime application today. Contact Baker Lime to request ag lime products for your crops.
Lime for Gardens
Table of Contents
Using Garden Lime for Healthy Plants
There are few things more rewarding than growing delicious vegetables and eating them when they’re at their ripest. Unfortunately, gardening isn’t always simple and, sometimes, you have to leave your garden up to nature. Many experienced gardeners will even tell you that they’ve struggled to yield a good crop at one point in time.
Pick up any gardening book or magazine, and you’ll likely see the word “lime.” Reading these publications may make it seem like lime is the magic solution to all of your garden’s problems. But just what is lime, and what does garden lime do?
When correctly applied, lime works to increase the pH of acidic soil. This creates a healthier base for plants to grow, because they’ll now have access to the nutrients and minerals they need to thrive. Garden lime is a powdered or pelletized product made from naturally occurring minerals. It has been used safely in agriculture for over a thousand years to change the soil pH, making it easier for plants to take up minerals and nutrients from the soil.
Lime also promotes the spread of new, good bacteria in your garden by supplying critical nutrients like phosphorus and zinc in your soil. Limestone also enables you to fertilize your garden more effectively, which means you won’t have to spend a lot of money to have a beautiful garden. To help your garden reach its full potential, apply garden limestone to your soil.
If you slept through high school biology and chemistry, don’t worry. Modern soil tests conducted at your local garden center or Cooperative Extension office can help you understand your soil’s pH and whether or not you need to adjust it to grow a lawn, flowers or a vegetable garden. Commercial lime products, such as pelletized lime, make it easy to add just the right amount to adjust soil pH.
Where Does Lime Come From?
Garden lime is mined from deposits formed millions of years ago. During that time, shallow seas covered much of the Earth, and prehistoric sea creatures lived in those waters. The creatures’ shells, composed largely of calcium, formed the deposits known today as limestone.
Using lime in the garden is one of the earliest known gardening techniques. For centuries, farmers have been transforming limestone and other rocks into lime powder to spread on their gardens and farms. In years past, they may not have known exactly what magic worked under the soil, but today, we know lime does several beneficial things to the soil. Lime is great for:
- Raising soil pH, which is necessary in many parts of the agricultural world to grow crops in acidic soils near human habitation.
- Adjusting the soil pH to grow a wide range of crops that people may not have been able to grow in that area before.
- Adding calcium and magnesium to the soil, two elements needed for vegetable and flower production. A lack of these minerals can cause malformed vegetables, poor fruit set or dropped fruits and vegetables.
- Making nutrients more readily available to plants, especially nitrogen.
- Helping herbicides work more efficiently.
- Aiding beneficial soil bacteria and microbes, which improve the health of your garden soil.
Among all the amendments you’ll want to buy for your garden, lime is among the best things you can bring in. Knowing how much to add, when to add fertilizer to a garden, the type of lime to buy for your needs, and asking the important questions like “can hydrated lime be used in the garden” can help you garden more efficiently and effectively.
Understanding Garden Soil pH
Before learning more about lime and garden lime uses, it’s important to understand a basic chemistry concept called pH. The pH scale measures hydrogen ions on a scale ranging from 0 to 14. You’ve probably heard the terms acid and alkaline. Those terms refer to the far extremes of the scale, with 0 being a pure acid and 14 being a pure alkaline. The midpoint, 7, is called neutral.
Most living organisms prefer a pH somewhere near the neutral portion of the range, although variations aren’t uncommon. Among plants, different plants prefer different soil pH, depending on where the species evolved.
Blueberry plants, for instance, evolved in the acidic soils of rocky, cold areas, and so they require a garden soil pH of 4 to 5.5 for best production. Blueberries are an extremely acid-loving plant so you may be looking at how to make garden soil more acidic. On the opposite end of the spectrum are vegetables such as asparagus, which can tolerate an extremely alkaline soil pH of up to 8.0, almost unheard of among vegetables.
Most gardening books recommend that vegetable garden soil offers plants a pH of 5.5 to 6.5. This range creates the ideal conditions under which plants can absorb nutrients and trace minerals through their root system. Complex soil bacteria and fungi attached to the root systems of plants and found in colonies throughout the soil break down organic matter into its components. Water then transfers those components to the plant’s roots. If the soil pH is within the appropriate level for your plants, they can absorb these nutrients easily and effectively.
When the soil pH isn’t within a usable range for a plant species, diseases occur. For example, blossom end rot, a problem in tomatoes, occurs for many reasons, but one important reason is improper soil pH. When soil pH is too low or too high for tomatoes, they can’t absorb calcium, an important mineral necessary for good fruit development. Black, flat spots called blossom end rot then develop in the tomatoes.
Adding lime to change the soil pH as well as adding simple organic materials, such as a sprinkle of Epsom salts (magnesium sulfate), makes the calcium and magnesium in the soil available to the tomato plants. They can then effectively use these minerals to produce an abundance of quality tomatoes. As you can see, what goes on in the soil, even at the microscopic chemical level, directly affects the health and productivity of your vegetable garden.
The Importance of Soil Maps and Soil Testing
The United States Department of Agriculture has actually produced soil maps showing the general soil types found throughout the United States. It’s a great place to start if you want to understand the basic structure of the soil in your area. Soil maps will help you understand whether your part of the country generally has an acidic or alkaline soil, and you’ll find the the type of soil (clay, loam or sand) you’ll most likely see in your county.
Once you have an overview of the soil in your area, it’s time to get a soil test done to know the exact pH of your garden soil. Not sure if you should add lime to your garden? The only way to know for sure whether or not your garden needs lime is to have a professional soil test completed.
Dig your soil sample from the area where you want to plant your vegetable garden, flowers or lawn. Dig up about half a cup of soil from approximately four to six inches below ground level. Take several samples and mix them together in your container. Label the container and bring it to the lab.
When you’re conducting soil tests, keep the following in mind:
- Conduct a soil test at least three months before you intend to plant in the area. This gives you plenty of time to have the test completed and to add anything recommended by the test, such as garden lime or fertilizer.
- Only use samples from among holes dug in a single-use area. For instance, if you’re planting both a lawn and a vegetable garden, don’t mix soil samples from the lawn area with those from the vegetable garden area. You want only vegetable garden soil in one sample and lawn soil in another.
- If you’re recycling a bucket or container to use for your soil test, clean and dry it thoroughly before adding soil samples to it. Any residual chemicals can affect the test readings.
- Use only plastic or glass containers. Metal can change the results.
- Tell the person conducting the soil test what you intend to plant in the area from where you’ve drawn the soil sample. They may recommend different amounts of lime to adjust the soil pH based on what you intend to grow.
Even if you’ve had your garden soil tested in previous years, it’s a good idea to get it tested each year in early spring. Adding commercial fertilizers to the garden can acidify the soil, changing the pH and pushing it outside healthy levels to grow your garden. Testing garden soil before adding lime and other amendments ensures you’re adding the right amount.
When to Apply Garden Lime
Some experts recommend adding lime at the end of the growing season to give it enough time to work through the soil. Lime needs time to react with water in order to be beneficial to your garden, so at the very least, it needs several weeks or months to adjust the pH and help make more nutrients available to your plants.
If you get your soil tested at the end of the winter, add lime immediately as recommended by the test results. Lime works best when mixed or tilled into the soil at the depth in which your garden will be planted — so don’t just spread lime on the surface of the vegetable garden and hope it works. Mix it into the soil well before your frost-free date indicates you can plant your vegetables or flowers.
Gardens found in acidic soil areas benefit from annual or bi-annual applications of garden lime. Raised bed gardens may get away with fewer applications. A soil test, however, is the best way to tell whether or not it is time to apply garden lime.
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How Much Lime to Apply
The results of your garden’s soil test will help you determine how much lime to apply. You’ll need to know your soil’s starting pH and the composition or soil structure. Soil generally falls into three categories:
- Clay soil: This soil type is characterized by tiny soil particles that stick together, making drainage difficult. Clay soil may dry into hard sheets that are tough to work with or dig into. It may have plenty of nutrients for plants, but the plant’s roots have a hard time breaking through the tiny particles to get to them.
- Sand: Sandy soil has the largest particle sizes and the lowest amount of nutrients. Water drains away rapidly through sandy soil.
- Loam: Loamy soil is the ideal soil type. It’s an equal mix of clay, sand and organic material that forms a rich soil base that almost all plants love. Very few gardens naturally have loamy soil, but loam can be created from other soil types through the careful application of compost and other organic materials.
To determine how much lime to add to your garden, first examine your soil or the previously mentioned soil maps to see what kind of garden soil you’re working with. If you’re not sure, you can do a simple soil structure test at home:
- Take a glass or plastic jar like an empty, clean jelly jar or mayonnaise jar with a screw top lid.
- Place about one cup of garden soil into the jar and fill the jar with water.
- Screw the lid onto the jar and shake the mixture for 30 seconds.
- Set the jar down and wait five minutes.
Here’s what the results can tell you:
- If the water is clear and most of the soil settled back onto the bottom of the jar, you have sandy or sandy loam soil.
- If the soil particles remain in suspension and the water looks murky and cloudy after five minutes, you most likely have clay soil. The tiny clay particles remain suspended in water much longer than sandy soil or loam.
Another way to test your soil is to scoop up about a tablespoon of garden soil into the palm of your hand. Add a few ounces of water and roll the soil to form a ball. The less water you need to form a ball, the higher the clay content. If the soil never forms a ball at all, it’s very high in sand content. The bigger sand particles don’t cling together the way tiny clay particles do in water.
Now that you know your garden’s approximate soil composition, here’s how to estimate lime needs. All figures are taken from Cornell University’s Cooperative Extension site. The following information will help you raise your garden soil pH to 6.5 for a vegetable garden. The amount of lime in the “Add” column is for 100 square feet of garden soil and assumes it will be mixed into the soil.
Using Limestone for Gardening
Types of Lime for the Garden
There are many types of lime available at the store, but the best ones to use for your vegetable or flower gardens are pelletized lime and powdered lime:
- Pelletized lime: Pelletized lime is evenly sized pellets of lime. It’s very easy to spread, especially on lawns. You can apply it to the surface, and it is activated by water.
- Powdered lime: There are different types of powdered lime. Each uses a different type of agricultural spreader to evenly distribute lime at the surface where it can be tilled into the soil.
Lime is usually sold in large bags or sacks. It should be kept dry until you are ready to use it, so store it in a garage or shed. Water can penetrate the sack and dissolve the lime, making it unusable.
How to Apply Lime to Your Garden
Most home gardeners use a lime or drop spreader to spread powered lime on lawns and gardens. A lime spreader is a machine you walk behind and push. It has a hopper in the front that you fill with powdered lime. A spreader then sprays out the powder in even amounts as you push the machine forward.
To apply lime to lawns, fill the lime spreader with the appropriate amount of lime. Walk in a straight line, making sure to spread the lime in the same direction with each pass of the spreader to avoid a ‘checkerboard’ look to the lawn.
Lime for garden soil can also be scattered using a spreader. If you don’t want to use a spreader, however, you can use a shovel to spread lime over the soil surface.
The lime should be tilled or dug into garden soil to mix it in so it’s more readily available to your garden plants. Mix it into the soil at a depth of about four to six inches. Lime applied to the soil’s surface will drip down about four inches after several rainstorms, but tilling or mixing it in makes it work faster at the root level where it can be of most benefit.
Lime needs water to mix into the soil and become available to plants. It’s not a quick fix. You won’t see your lawn turn a rich, emerald green after applying lime. Think of lime like vitamins for the soil. When you take a vitamin pill, you’re taking vitamins to boost your long-term health, not for quick energy. Adding lime to the soil is like a vitamin. It’s for the long-term health of the soil and your plants.
Lime for Lawns
Lime can be very beneficial for lawns. Lawns that have yellow patches, brown patches, weedy areas or an abundance of moss may benefit from an even application of lime. Weeds or mossy patches can both be signs that the pH of specific areas on the lawn differ from the overall pH of the lawn. Moss, for example, grows in acidic conditions — which can be improved by the addition of lime.
Adding lime to your lawn also does more than just raising the soil pH. Lime also adds calcium, which in turn helps grass absorb trace elements such as zinc, copper and others. By adding lime, you’ll boost the overall health of your lawn. An even spread of lime can correct many deficiencies and adjust the pH of the lawn over the growing season so the problems disappear.
Apply lime to lawns in the fall. Rain and cool temperatures help lime move into the soil. It can take up to two years to see a benefit from adding lime to the soil since it moves slowly from the surface to the roots, but don’t overdo lime application.
What Vegetables Like Lime?
Depending on your soil, you may need to add lime throughout the vegetable garden. Some plants love a little extra lime because they prefer “sweeter” soils, or soils with a slightly more alkaline quality to them. Remember that adding lime raises the pH of the soil.
Pay particular attention to beds where the following vegetables and fruits will be grown:
- Lime for tomatoes: Lime for tomatoes is almost a given in most garden soil. Soils that are even slightly too acidic won’t produce good quality tomatoes and will bind calcium and magnesium into the soil where plants cannot access it. Lime changes the soil pH to make those nutrients accessible to tomatoes, preventing blossom end rot and premature tomato drop. Lime for tomatoes is a good idea. Tomatoes need soil pH from 5.5 to 7.5.
- Lime for soybeans: Adding lime to fields prior to planting soybeans is also an excellent idea. Lime for soybeans also includes all legumes which prefer a more alkaline soil. Some growers claim that lime can even double a soybean crop yield.
- Lime for squash: Both winter and summer squash love soil that’s slightly more alkaline, with tolerance levels of up to 7.0 for soil pH. Adding lime to most soils improves squash plant yields.
- Lime for asparagus: Among the list of common garden vegetables, asparagus is probably the one that loves lime the most. Lime for asparagus is necessary to give the plant the ‘sweet’ alkaline soil it craves. Asparagus only needs a slightly alkaline soil, but it can tolerate soil pH up to 8.0. Because asparagus plants are left in the garden year-round, and an asparagus bed produces more crop the older it is, you may need to add a slow-release lime that’s gentle on plants. Pelletized lime offers a good option.
- Lime for cantaloupe: If you plan to grow cantaloupe, adding lime can also improve the amount and flavor of the melons. Cantaloupe prefers a soil pH of 6.0 to 7.5, leaning toward the alkaline side. Lime for cantaloupe raises soil pH to the alkaline level.
- Lime for onions: Lime for onions raises the soil pH to between 6.0 and 7.0, which is what onions prefer in order to develop large, tasty bulbs.
- Lime for parsnips: Parsnips need a long growing season, so when adding lime for parsnips, add it in the early spring and again after harvesting parsnips in the late fall. Soil pH for parsnips should be between 5.5 and 7.5.
- Lime for lettuce: Almost all lettuce varieties benefit from a little lime, and lime for lettuce can help your plants develop strong, tasty leaves. Lettuce needs a soil pH between 6.0 and 7.0.
Which Plants Don’t Like Lime?
Any plants considered “acid-loving” plants shouldn’t be given extra lime. This includes blueberries as well as ornamental shrubs such as azaleas, rhododendrons and hollies.
If you’re adding garden lime to a flower bed where azaleas and other acid-loving plants are located, keep the lime away from the roots of the plant. Remember that the roots extend out under the soil in an umbrella-like shape under the ground. The drip line, or the imaginary line around the shrub where the leaves extend in a circle, is the line underground where the roots grow.
When you’re not sure about which plants like lime and which don’t, look them up online or in a good reference book.
Can Plants Have a Lime Deficiency?
Plants don’t need lime to survive, but they do need the trace minerals that often accompany lime, such as calcium and magnesium. They also need the soil pH to be within an acceptable range for their species so they can absorb these minerals and others elements from the soil for growth and development.
Plants that suffer from a nutrient deficiency may benefit from lime added to the soil. It’s hard to tell whether a problem is caused by nutrient deficiency, horticultural practices, microorganisms or insects, but you can spot nutrient deficiencies in vegetables and other plants by these symptoms:
- Distorted, misshapen leaves.
- Leaves that are yellow or turn yellow over time.
- Poor production of vegetables.
- Vegetables or fruit fall off the plant prematurely.
- Plant appears stunted or fails to thrive.
While adding lime may not cure nutrient deficiencies, combining it with a good-quality fertilizer containing trace elements of essential nutrients can help. Because lime changes the soil pH, it can make the nutrients more readily available to the plants, and the fertilizer can provide the extra nutrients plants may need. Over time, the plant can correct the nutrient imbalances.
If you’re not sure what’s causing your plant problems, consult your local Cooperative Extension office or take a sample of your plant to your local garden center for diagnosis and assistance.
What to Do If You Use Too Much Lime
You know the old saying, “You can never have too much of a good thing?” Well, you can have too much lime. Sometimes you just get overzealous with the spreader. Other times, a bag will break as you’re hauling it out to the garden, dumping lime everywhere. What should you do if you use too much lime?
First, if it’s on your lawn or another area where you can scoop it up, scoop up as much scattered lime as you can. If you’ve actually mixed it into the soil before you realized you added too much, don’t panic. There’s still a few things you can do to help.
Lime raises soil pH, but the following amendments lower soil pH. If you’ve added too much lime, the following can swing the pH balance back to the acidic side:
- Sulfur: Garden sulfur or elemental sulfur is one of the most effective treatments for alkaline soil. Soil bacteria feed on the sulfur and lower soil pH in the process. Sulfur is spread or mixed as a powder into the soil, and you can often find small bags of it at the garden center. Be sure to check with the garden center or your local Cooperative Extension office for application rates. These rates depend on how much lime you accidently added to the soil and how low you need your pH to go.
- Peat moss: Some gardeners don’t like the recommendation to use peat moss because it is harvested from ancient deposits that once depleted are gone for good. But peat moss is one of the most effective organic garden acidifiers. It’s expensive, but it works well to both lower pH and improve soil texture. You can purchase it in large bales or bags and mix it into the soil. It won’t harm plants, and it will improve drainage in clay soils.
- Manure: Manure is a little tricky to use because you will need to make sure you use well-rotted or composted manure in the garden. Animal manure such as cow, horse, sheep, rabbit and goat manure makes a fine garden soil amendment, adding both nutrients and acidity to the soil. It can counteract excessively alkaline soils or the effects of too much lime added to the soil. You can often find free sources of manure from local horse stables, but be sure to let it sit and rot for a while before adding it to the soil.Under no circumstances should you ever use manure from carnivores such as dogs, cats, pigs or similar animals. Such manure can harbor harmful bacteria and parasites.
- Compost: Compost isn’t strictly a soil acidifier, but it’s so good for your garden soil that it must be mentioned. It has a slightly acidifying effect on the soil, especially if it’s made from a higher balance of leaf matter than other garden debris.
Compost improves soil fertility and health, adds beneficial microbes and balances pH that’s slightly off if you’ve added just a little too much lime. Since you can’t overdo the compost, add as much as you want — as long as it is well-rotted and mixed into the soil prior to planting. Well-rotted compost smells sweet and has the look of crumbled chocolate cake.
Storing Extra Lime
Garden lime will “keep” for next year if you’ve purchased a little more than you need. Store it in a cool, dry place like a shed or garage. Stack bags of lime on pallets, blocks or bricks to keep it off of a concrete floor so the bags do not get damp.
Be Smart When Adding Lime to the Garden
Buying garden lime, such as lime from Baker Lime, can be very helpful in the home garden. But before adding lime, make sure you get a soil test to see how much you actually need. You may be pleasantly surprised and need less than you thought you did. Or, you may need more.
Excess lime usually dissolves into the soil, but the effects can last for a long time. That’s another great reason to know exactly how much lime to add to your garden soil before spreading it.
If you’re constantly battling against acidic soil, you may wish to investigate growing a raised bed vegetable garden. Raised beds provide you with a controlled planting area you can more easily amend than an in-ground garden. In addition, when you start with bagged garden soil, your vegetable garden will begin with soil that’s better than what you may have available naturally.
Raised bed gardens can also be ideal for people living in areas with poor soil or on land that’s been heavily farmed or planted with pine trees — which turn soil very acidic. You will still need to check the soil pH each year and add lime as needed, but probably not as much.
Your plants know what they need, so work with nature and not against it when you’re planning your garden. If your soil is naturally acidic, choose plants that thrive in a lower pH soil. Even when adding plenty of good-quality lime products from Baker Lime to the soil, you may still struggle to keep the pH high enough to satisfy alkaline soil-loving vegetables, like asparagus, if your soil is naturally sour or acidic.
Most vegetables, however, are tolerant of a wide range of soil pHs and conditions. If you’ve tried to grow certain vegetables and didn’t have much luck, adding lime may improve your chances of a good harvest.
Where Can I Buy Garden Lime?
If you need lime for your garden, you’ve come to the right place. Since 1889, Baker Lime has supplied farmers, landscapers and homeowners with high-quality lime mined from our own dolomite deposits in the heart of York County, PA. As one of the most well-known and trusted lime suppliers on the East Coast, we supply customers in New York, Pennsylvania, Delaware, West Virginia, Virginia, New Jersey, Maryland and beyond. You can request a quote online.
For over 125 years, we have built our reputation on providing our industrial, commercial and residential customers with the limestone products they need to transform their gardens. As you search for limestone for your garden, our friendly staff can answer your questions and provide free quotes! Contact us today to find the limestone you need at the best value.
Our lime can help your garden and lawn flourish, diminish plant problems and improve the quality and quantity of vegetables and fruits. It also adds to the health of your soil, helps plants absorb nutrients and is an all-natural product from American sources.
For more information or to obtain a price quote from Baker Lime, contact us today.
An acid is defined as a substance that tends to release hydrogen ions (H⁺). Conversely, a base is defined as a substance that releases hydroxyl ions (OH⁻). All acids contain hydrogen ions, and the strength of the acid depends upon the degrees of ionization (release of hydrogen ions) of the acid. The more hydrogen ions held by the exchange complex of a soil in relation to the basic ions (Ca, Mg, K) held, the greater the acidity of the soil.
NOTE: Aluminum (Al) also contributes to soil acidity, but for simplicity, further discussion of soil acidity will be limited to H as the cause of soil acidity.
Desirable Soil pH for Optimum Crop Production pH Range
The desirable pH range for optimum plant growth varies among crops. While some crops grow best in the 6.0 to 7.0 range, others grow well under slightly acidic conditions. Soil properties that influence the need for and response to lime vary by region. A knowledge of the soil and the crop is important in managing soil pH for the best crop performance.
Soils become acidic when basic elements such as calcium, magnesium, sodium and potassium held by soil colloids are replaced by hydrogen ions. Soils formed under conditions of high annual rainfall are more acidic than are soils formed under more arid conditions. Thus, most southeastern soils are inherently more acidic than soils of the Midwest and far West.
Soils formed under low rainfall conditions tend to be basic with soil pH readings around 7.0. Intensive farming over a number of years with nitrogen fertilizers or manures can result in soil acidification. In the wheat-growing regions of Kansas and Oklahoma, for example, which have soil pH of 5.0 and below, aluminum toxicity in wheat and good response to liming have been documented in recent years.
Factors Affecting Soil Acidity
Rainfall contributes to a soil’s acidity. Water (H₂O) combines with carbon dioxide (CO₂) to form a weak acid — carbonic acid (H₂CO₃). The weak acid ionizes, releasing hydrogen (H⁺) and bicarbonate (HCO₃). The released hydrogen ions replace the calcium ions held by soil colloids, causing the soil to become acidic. The displaced calcium (Ca⁺⁺) ions combine with the bicarbonate ions to form calcium bicarbonate, which, being soluble, is leached from the soil. The net effect is increased soil acidity.
Nitrogen levels affect soil pH. Nitrogen sources — fertilizers, manures, legumes — contain or form ammonium. This increases soil acidity unless the plant directly absorbs the ammonium ions. The greater the nitrogen fertilization rate, the greater the soil acidification. As ammonium is converted to nitrate in the soil (nitrification), H ions are released. For each pound of nitrogen as ammonium, it takes approximately 1.8 pounds of pure calcium carbonate to neutralize the residual acidity. Also, the nitrate that is provided or formed can combine with basic cations like calcium, magnesium and potassium and leach from the topsoil into the subsoil. As these bases are removed and replaced by H ions, soils become more acidic.
Legumes like soybeans, alfalfa and clovers tend to take up more cations in proportion to anions. This causes H ions to be released from plant roots to maintain the electrochemical balance within their tissues. The result is a net soil acidification.
Even if the top 6 inches of soil show a pH above 6.0, the subsoil may be extremely acidic. When subsoil pH’s drop below 5.0, aluminum and manganese in the soil become much more soluble, and in some soils may be toxic to plant growth. Cotton and, to some extent, soybeans are examples of crops that are sensitive to highly soluble aluminum levels in the subsoil, and crop yields may be reduced under conditions of low subsoil pH. If you’ve observed areas of stunted plants in your field, take a subsoil sample in these areas. If the soil pH is extremely acidic (below 5.2), lime should be applied early in the fall and turned as deeply as possible.
Liming Soil Pays
Correcting soil acidity by the use of lime is the foundation of a good soil fertility program. Lime does more than just correct soil acidity. It also:
Supplies essential plant nutrients, Ca and Mg, if dolomitic lime is used
Makes other essential nutrients more available
Prevents elements such as Mn and Al from being toxic to plant growth.
Liming materials contain calcium and/or magnesium in forms, which when dissolved, will neutralize soil acidity. Not all materials containing calcium and magnesium are capable of reducing soil acidity. For instance, gypsum (CaSO₄) contains Ca in appreciable amounts, but does not reduce soil acidity. Because it hydrolyzes in the soil, gypsum converts to a strong base and a strong acid as shown in the following equation:
CaSO₄ + 2H₂O = Ca (OH)² + H₂SO₄
The formed Ca (OH)² and H₂SO₄ neutralize each other, resulting in a neutral soil effect. On the other hand, when calcitic (CaCO₃) or dolomitic lime (Ca Mg (CO₃)²) is added to the soil, it hydrolyzes (dissolves in water) to a strong base and a weak acid.
CaCO3 + 2H₂O = Ca (OH)² + H₂CO₃
Calcium hydroxide is a strong base and rapidly ionizes to Ca⁺⁺ and OH⁻ ions. The calcium ions replace absorbed H ions on the soil colloid and thereby neutralize soil acidity. The carbonic acid formed (H₂CO₃) is a weak acid and partially ionizes to H⁺ and CO₂⁻² ions. Therefore, the net effect is that more ca than H ions are released in the soil, and consequently, soil acidity is neutralized.
Ground limestone contains mostly calcium carbonate and generally has less than 1 to 6 percent magnesium. Its neutralizing value depends on its purity and fineness of grinding.
Ground limestone is a mixture of calcium carbonate and magnesium carbonate. In some states, it must contain at least 6 percent Mg to be classified as dolomitic lime. Its neutralizing effect also depends upon its purity and fineness of grinding.
Hydrated lime (Ca (OH)²) is calcium hydroxide, sometimes called slaked or builder’s lime. Hydrated lime is powdery, quick-acting and somewhat unpleasant to handle. The neutralizing value ranges between 120 and 135 compared to pure calcium carbonate. Fifteen hundred pounds of hydrated lime with a neutralizing value of 135 is equivalent to 2,000 pounds of agricultural lime with a neutralizing value of 100.
Marls are deposits of calcium carbonate mixed with clay and sand that are found mostly in the Coastal Plain section of the Eastern states. Their neutralizing value usually ranges from 70 to 90 percent, dependent on the amount of impurities, mostly clay, that they contain. Their usefulness as a liming material depends on their neutralizing value and the cost of processing. They are often plastic and lumpy, and must be dried and pulverized before application to the soil. Marls are usually low in magnesium. Their reaction with the soil is the same as calcitic lime.
Basic slag is a product of the basic open-hearth method of making steel. The calcium contained is in the form of calcium silicate, and reacts with soil acids in a manner similar to ground limestone. Its neutralizing value ranges from 60 to 70, but since basic slag generally has smaller particles than agricultural lime, it tends to change soil pH more rapidly than conventional agricultural lime. It also contains P₂O₅ ranging from 2 to 6 percent and some micronutrients and magnesium.
Ground Oyster Shells
Oyster shells and other seashells are largely calcium carbonate. They make a satisfactory liming material when finely ground and have a neutralizing value of 90 to 110. Since they are composed of primarily calcium carbonate, they contain little or no magnesium.
A liming material commonly referred to as fluid lime generally consists of finely ground limestone suspended in water at a ratio of about 50 percent water to 50 percent limestone. In most instances, producers of fluid lime utilize very finely ground limestone – most of which will pass a 200-mesh screen. Fluid lime is capable of changing soil pH in a relatively short period of time. This is a distinct advantage in situations in which liming has been delayed to just before planting, or in situations in which low soil pH is discovered after a crop is planted. Keep in mind, since fluid lime contains approximately 50 percent water, this means that a farmer applying fluid lime at the rate of 1,000 pounds per acre would be applying only 500 pounds of limestone.
Pelletized lime is finely ground agricultural limestone that is pelletized with the aid of clay or synthetic binders to produce pellets in the 5- to 14-mesh range. Usually, about 70 percent of the initial limestone, prior to pelletizing, passes 100- to 200-mesh sieves. It may be spread with conventional spinner fertilizer spreaders, which makes it attractive to use. Unpublished research indicates that pelletized lime should be allowed to react with a good rainfall or irrigation on the soil surface to disperse the pellets before it is mixed with the soil. If rates of 250 to 500 pounds of this liming material are mixed with the soil before the pellet “melts” down, a limited soil volume may be affected by each pellet, and desirable pH adjustment of the plow layer may not be achieved.
Use of Fluid Lime and Pelletized Lime
Fluid and pelletized lime are excellent sources of lime to be used under certain circumstances such as: Correction of a low soil pH condition after a crop is planted; A rapid change in soil pH if liming is delayed to just before planting a crop; For maintaining pH in the optimal range for plant growth and yield. However, these two liming materials should not be depended upon to maintain the soil pH during the full crop-growing season if applied at one-fourth of the recommended lime rate.
Fineness of Grinding is Important in Selecting Liming Materials
Lime quality is measured by how effectively it neutralizes soil acidity. This is determined largely by its chemical purity and size of particles. The purity of lime is expressed as calcium carbonate equivalent (CCE). This is a measure of how much of the material can react with the soil to neutralize acidity under ideal conditions compared to pure calcium carbonate. Limestone should have a neutralizing value of at least 90 percent. Even if the CCE of lime is satisfactory, it will not neutralize soil acidity unless the limestone is finely ground. In an attempt to arrive at a more accurate lime rating to measure liming material effectiveness, some states’ soil test laboratories have adopted effective calcium carbonate content for rating liming materials. An efficiency rating is arrived at by multiplying the calcium carbonate equivalent times the effective calcium carbonate content, which is based on the fineness of the liming material.
Efficiency Factors for Liming Materials
The following example of the “effective neutralizing value” (ENV) calculation, used by the University of Illinois, serves to illustrate the importance of lime particle size in potential soil acidity neutralization. ENV = Total fineness efficiency x (% calcium carbonate equivalent / 100).
Assume that a liming material has a 96 percent calcium carbonate equivalent. After screening, the liming material is found to have the following particle size distribution:
+8 mesh = 4% –8 to +30 = 25% –30 to +60 mesh = 26% –60 mesh = 45%
The total fineness efficiency factor may be calculated as follows for the example material:
Total Fineness Efficiency for 1st Year = 63.20
Therefore, the effective calcium carbonate content of ENV = 63.20 x (96/100) = 60.67 for this example of liming material for the first year.
These calculations enable a grower to determine the shorter- and longer-term value of the liming material being considered for purchase.
Most mid-Atlantic and southeastern states use the Mehlich I (double acid) solution to extract P, K, Ca, Mg, Mn and Zn. Most Midwestern states use the Bray I solution for extracting P. For K, Mg and Ca, ammonium acetate is used. In regions having calcareous soils, such as the western Corn Belt and Great Plains, the Olsen test is used to extract P.
Efficiency Factors: Timing, Placement and Frequency of Application
For crop rotations that include legumes like alfalfa or clovers, lime should be applied to allow enough time for reaction with the soil before the legumes are planted. Ideally, lime should be applied three to six months ahead of seeding the targeted crop. Applications as late as just before planting, with good soil incorporation, can still be beneficial on strongly acidic soils. Some reduction in soil acidity will still occur, although maximum pH increases are not normally reached until about one year after application of typical agricultural limestone.
Placement is just as important as lime quality. Maximum contact with the soil is essential for neutralization of soil acidity. Most common liming materials are only sparingly soluble in water. For example, ammonium nitrate is about 84,000 times more soluble than pure calcium carbonate. Even if lime is properly mixed into the plow layer, it will have little reaction if the soil is dry. Moisture must be available for the lime-soil reaction to occur. Perhaps the best way to incorporate lime or any other material with the plow layer is to use two perpendicular passes of a combination disc, followed by a chisel plow. Deep plowing of lime does not achieve desirable mixing in the upper 6 to 8 inches of soil. However, because the plow or a heavy breaking disc inverts the lime, it can help to distribute the lime in the upper portion of the subsoil. Choice of tillage equipment will depend on the depth at which soil acidity neutralization is most needed. Good horizontal and vertical mixing of the lime provides the best results. In some cropping systems, like established perennial sods or established no-till crop production, mixing lime with the plow layer is not possible. Lime should be incorporated to adjust the pH in the plow layer before the establishment of these cropping systems. Once the desired pH is reached, it can be maintained by surface applications in these no-tillage systems. Surface-applied lime reacts more slowly than lime that is mixed with the soil, and usually only affects pH in the upper 2 to 3 inches of soil. Research at Pennsylvania State University indicated that surface applications of limestone in no-till crop production can begin to influence soil pH below the 2-inch depth after the fourth year, if lime is applied about every third year. Surface liming every third year with 6,000 pounds of lime/A was just as beneficial as annual lime applications of 3,000 pounds/A.
The more intensive the crop production, the higher the nitrogen fertilizer or manure use, and the greater the crop yields (and nutrient removal), the greater and more frequent the need will be for lime. Soil sampling is the best way to evaluate soil pH levels and the need for lime.
Excess Alkalinity – Natural and Induced
Many soils in the semi-arid and arid regions of the United States have a naturally high pH. They may contain significant quantities of “free calcium carbonate.” However, these areas are not the only ones with problems associated with high pH. Irrigation well water may contain significant quantities of calcium and/or magnesium carbonate in certain regions of the United States. In areas of the mid-South for example, some irrigation well water contains in excess of 3 to 5 milliequivalents of bicarbonate per liter and 3 to 5 milliequivalents of calcium. An acre-foot of water or more per year can deliver more than 300 to 600 pounds of calcium and/or magnesium carbonate (lime) per acre. Sprinkler irrigation systems tend to deliver the lime in the water uniformly across the field. If “flood” or furrow irrigation systems are used, much of the lime from the water may precipitate in the upper regions of fields nearest the water delivery inlets and in the water flow path. In effect, the soil is limed by the irrigation water. If the water distribution and delivery are the same over several years, the soil may become alkaline, with soil pH levels rising to 7.0 and above. Soil pH increases may approach 0.2 pH units per year, until equilibrium is reached with atmospheric carbon dioxide levels. Such soil pH increase will occur more rapidly on coarse and medium-textured soils than on clays, which are more highly buffered.
If the well water contains significantly more sodium compared to calcium or magnesium, there may be a risk of sodium buildup on soils that do not readily leach. This is more often a greater concern in arid regions than in humid regions. Soils with naturally high sodium levels, or those that have received large quantities of sodium bicarbonate through irrigation, may have pH levels as great as 8.5 or higher. Theoretically, if sodium is not a factor, even if large quantities of calcium or magnesium carbonate are applied, the soil pH will not exceed 8.2 to 8.3. At pH 8.2, the soil carbonate reaches an equilibrium with the carbon dioxide level in the atmosphere. If irrigation water is suspected or known to deliver significant amounts of lime salts and/or soluble salts, soil samples should be collected more frequently to better monitor soil pH, salinity and cation balance. Irrigation water quality should also be periodically monitored.
Correction of Excess Alkalinity by Soil Acidulation
Elemental sulfur may be used to acidify alkaline soil to the desirable pH range. It may also be used to maintain pH in the desirable range, on soils that tend to become alkaline with management. When elemental sulfur is applied to soil, it combines with oxygen and water to form sulfuric acid. This oxidation of sulfur is brought about by certain microorganisms, and it may take from three to six weeks or longer, depending on the soil conditions. The finer the sulfur is ground, the more rapid the conversion to sulfate and dilute sulfuric acid. The rate of decrease in pH with elemental sulfur may be similar to the rate of pH increase brought about by liming. The more free calcium carbonate present and the more buffered the soil, the longer it will take to acidify the soil. More sulfur will also be needed on soils with free carbonates present. Aluminum sulfate is another amendment often used in ornamental horticulture to acidify soil in plant beds. However, more of it is needed to produce the same acidification as elemental sulfur, even though it offers the advantage of a faster reaction. Compared to elemental sulfur, the rate may need to be two to seven times greater. Little of this amendment is used in commercial agriculture.
NOTE: If free carbonates are present, higher rates than those shown will be required. Reference: “Western Fertilizer Handbook,” eighth edition. California Fertilizer Association
As with soil testing, an important phase of plant analysis is sample collection. Plant composition varies with age, the portion of the plant sampled, the condition of the plant, the variety, the weather and other factors. Therefore, it is necessary to follow proven sampling instructions. Most laboratories provide instruction sheets for sampling various crops, plus information sheets and directions for preparing and submitting samples. It is usually suggested that samples from both good and problem areas be submitted for comparison when diagnosis is the goal. Because experience and knowledge are vital in sampling plants correctly, agricultural advisors or consultants often do the job.
The Four Basic Steps in Plant Analysis
Facts about Soil Acidity and Lime (E1566)
November 9, 2015 – Author: Laura Bast
Purchase item on Shop.msu.edu
1. What is lime?
According to chemical definition, lime is calcium oxide (CaO). In agriculture, lime is usually defined as calcium or calcium-magnesium containing compounds capable of reducing harmful effects of an acid soil by neutralizing soil acidity and raising the soil pH.
2. What is soil acidity?
Soils are acid because of hydrogen ions dissolved in soil solution (water in the soil) and held on the clay and humus particles. pH is a measure of the degree of acidity or alkalinity. A value below 7.0 is acid, 7.0 is neutral and above 7.0 is alkaline. As the soil pH decreases below 7.0, soils become more and more acidic.
3. What is active soil acidity?
Active soil acidity is the hydrogen that is dissolved in soil solution. Active soil acidity is determined in a soil pH measurement. It serves as a guide as to when to apply lime.
4. What is reserve acidity?
Reserve acidity is the acidity that is adsorbed on the surfaces of soil and organic matter particles. This portion of the soil acidity accounts for more than 99 percent of the total acidity. An accurate determination of lime need requires measuring this reserve acidity. Soil test labs use a special buffer pH method to determine the reserve acidity and lime requirement.
5. What is meant by neutralizing value (NV)?
Not all liming materials react the same on a poundfor-pound basis. Thus, it becomes necessary to establish a standard to evaluate the ability of liming materials to neutralize soil acidity. Pure calcium carbonate has a value of 100, and all other materials are chemically compared to this standard. Most liming materials contain impurities, so lime recommendations are made on the basis of a neutralizing value of 90 percent. If a liming material has an NV other than 90 percent, an adjustment will need to be made in the amount of lime to apply.
6. What is calcium carbonate equivalent?
Calcium carbonate equivalent (CCE) refers to the equivalent amount (pounds) of pure calcium carbonate in a ton or cubic yard of lime material. If a lime material has a NV of 85, it will have a CCE of 1,700 lbs per ton. If a source of marl has a calcium carbonate equivalent of 1,200 pounds, this means one cubic yard is as effective as 1,200 pounds of pure calcium carbonate.
7. What are the neutralizing values for commonly used liming materials?
8. Is particle size of lime important?
Nearly all of the lime should pass through an 8-mesh sieve and 50 percent should pass through a 60-mesh sieve. An 8-mesh sieve has openings approximately 1/8-inch in size. Lime particles that are finer than 60 mesh react more quickly than coarser particles (between 8 and 60 mesh). The coarser lime particles provide residual neutralizing power.
9. Where can I get lime analyzed?
Most soil-testing labs will analyze lime to determine its neutralizing value and particle size distribution.
10. What is calcic limestone?
Calcic limestone is a naturally occurring rock composed primarily of calcium carbonate. It is sometimes referred to as high calcium or calcitic limestone. It usually contains less than 5 percent magnesium carbonate and 90 to 95 percent calcium carbonate.
11. What is marl?
Marl is a soft calcitic material, which has settled out of water over long periods. Fine textured, it consists of calcium carbonate, clay and organic matter.
12. What is dolomitic limestone?
Dolomitic limestone is a naturally occurring rock composed primarily of calcium-magnesium carbonate (CaCO3•MgCO3).
13. How much magnesium does dolomitic limestone contain?
Dolomitic limestone being marketed in Michigan contains 15 to 45 percent magnesium carbonate by weight, the remaining 85 to 55 percent being largely calcium carbonate by weight. To determine the exact answer, an analysis of the material is required. The limestone analysis report usually expresses magnesium as percent magnesium carbonate. To convert to the elemental form, multiply the percent magnesium carbonate by 0.29. For example, a dolomitic limestone having 30 percent magnesium carbonate contains 174 pounds of elemental magnesium per ton (0.30 times 2,000 times 0.29). (Multiply by 2,000 to convert tons to pounds.)
14. When should I use dolomitic lime?
Use dolomitic lime when the soil test indicates the magnesium level is low to marginal. When the soil magnesium level is adequate, use either calcitic or dolomitic lime. There is no evidence that dolomitic lime has any harmful effects.
15. What is pelletized lime?
Pelletized lime consists of very fine calcitic or dolomitic limestone formed into pellets with a soluble binding agent. There is nothing special about the effectiveness of pelletized lime. It is chemically the same as traditional agricultural lime and neutralizes soil acidity the same way. Therefore, the rate needs to be the same as for agricultural lime to achieve the same effect.
16. What are the materials called fluid lime, liquid lime or lime suspension?
Finely ground limestone is suspended in water or a fertilizer nitrogen solution. The suspension usually contains 55 to 70 percent fine limestone (finer than 100 mesh), 25 to 40 percent water and 1 to 4 percent colloidal clay.
17. Are liquid lime materials better than dry lime?
Yes and no. These liming materials react quickly and bring about rapid increase in soil pH, but have limited residual effect for maintaining soil pH. One drawback may be that the total amount of lime that can be applied is usually less than with dry limestone. Thus, more frequent lime applications are needed. These materials also tend to be more expensive than dry agricultural lime.
18. Are wood ashes good for liming?
Yes. Check the soil pH first. If the soil pH is 6.5 or above, don’t apply wood ashes. When lime is required, apply up to double the lime requirement every three years. For example, if the lime requirement is 3 tons/acre, limit the application of wood ashes to six tons in a three-year period. (On a garden, this would be 275 pounds of ashes per 1,000 square feet.) Check the pH before you apply more.
19. What are the benefits of using lime?
Liming acid soils results in better crop yields by: a) raising soil pH, b) improving overall nutrient availability, c) reducing soluble aluminum and d) improving microbial activity. When available in excess, aluminum and manganese are harmful to plants, inhibiting cell division in plant roots and reducing growth. Plants with aluminum toxicity may also experience calcium or magnesium deficiencies. Maintaining proper soil pH maximizes the availability of several plant nutrients. Proper liming increases the efficiency of applied fertilizer.
20. Will liming pay?
Yes. Where needed, lime will return $5 to $10 for each dollar invested in lime. Raising the soil pH from 5.7 to 6.5 in mineral soils may improve corn or soybean yields by 20 percent or more, and alfalfa yield by 35 percent or more.
21. How much lime should I apply?
Use a soil test to determine the amount of lime needed. A soil pH measurement alone is not sufficient to determine lime requirement. Most soiltesting laboratories use a special buffer pH method to determine the amount of lime needed. Michigan State University uses the SMP buffer method.
22. How long will it take for lime to react with the soil and how long will it last?
Lime will react completely with the soil in two to three years after it has been applied; although, benefits from lime may occur within the first few months after application. How long the effects of lime last will depend on the kind of lime used, total soil acidity, amount of organic matter, kind and amount of clay, and cropping and management systems used. A soil test three to four years after lime application will help provide the answer.
23. What if my leased land needs lime?
Farmers tend to be hesitant about applying lime to land that they may or may not have for crop production the next year. Farmers need to recognize the benefit they can receive in crop production during the application year, and landowners need to recognize that lime maintains the quality of their land. When lime is needed on rented land, a farmer needs to seek a multiple-year lease to guarantee the return on his or her investment or ask the landowner to share the cost of the lime, prorated over a four-year period.
24. Should I lime my soil to pH 6.0, 6.5 or 6.8?
For most crops, liming to pH 6.5 is recommended. When alfalfa is grown, liming to pH 6.8 is essential. For gardens, potatoes or low-maintenance grass pasture, liming to pH 6.0 will be satisfactory. Some crops, such as blueberries, that grow well under acid soil conditions do not usually benefit from liming. When several different crops are grown in rotation, lime for the most pH sensitive crop.
25. Will fertilizer replace the need for lime?
No. When soil pH falls below 5.5, the concentrations of soluble aluminum and manganese increase greatly. Under very acid conditions, plants accumulate toxic amounts of these two elements. Since many fertilizers are acid forming, regular liming reduces the hazard of creating an acid subsoil, increases the efficiency of fertilizer used and gives greater crop yield.
26. Should I topdress lime on my established lawn?
Check the pH of the zero- to 3-inch soil depth and if it is below 5.5, topdress at a rate of 25 to 50 pounds of lime per 1,000 square feet. When establishing a lawn, test the soil and apply the recommended rate and mix it with the soil.
27. Is there additional information available?
Yes. The following bulletins are available from the Michigan State University Extension Bookstore or the MSU Extension Website.
E-471 – Lime for Michigan Soils
E-498 – Sampling Soils for Fertilizer & Lime Recommendations
E-2904 – Nutrient Recommendations for Field Crops in Michigan
E-2934 – Nutrient Recommendations for Vegetable Crops in Michigan
They are available online at bookstore.msue.msu.edu or at msue.msu.edu.
Tags: cover crops, farm management, field crops, lawn & garden, soils & composting
Related Topic Areas
Cover Crops, Soils & Composting, Lawn & Garden, Field Crops, Farm Management
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We’ve written about when to lime your lawn, and applying it in the garden and landscape as well. The use of lime for soil is a subject many homeowners write off as – unimportant. We’ll continue to bang the drum.
What Is Lime Used For?
Some garden experts suggest that lime is a soil amendment. Others claim that it is a soil conditioner.
These are both rather vague terms and leave the average homeowner/gardener still in the dark about the lime requirement.
Some authorities are more definite in their recommendations and say that lime is used to correct the soil structure and soil acidity. A few mention lime as a fertilizer, whereas others believe that it should never be considered as one.
Such general and conflicting statements are confusing to homeowners and may result in their hesitancy to use this rather cheap, innocuous white powder assumed to be of little apparent value.
Key To A Better Lawn and Garden?
However, as this “white powder” may be the key to a better lawn and garden, it behooves every gardener to gain a better understanding of its functions and value of gardening lime.
The first and most important purpose of lime is to change an acid soil to the proper reaction for the particular plants like vegetables to be grown.
When an expert is consulted concerning any trouble with plants and cannot immediately recognize the cause from the appearance of a plant, he will usually ask, “Is the soil acid?” Such a question would seem to imply that an acid soil is the cause of considerable trouble. You’ll confirm it is after you conduct a soil test using a soil sample.
Plant Preferences – Slightly Acid
The majority of plants commonly cultivated prefer a slightly acidic soil. Therefore, if the soil in your garden and lawn is medium to very acid it will be necessary to use lime to neutralize partially the garden pH and make it possible for you to grow vigorous, healthy plants. A great example of when to apply lime to vegetable gardens.
Conduct soil testing to know the pH levels and get a deeper understanding of the soil structure.
In acid soil, some of the desirable plant food elements are combined with other chemicals to form insoluble compounds.
Under such conditions, much of the plant food in the soil, as well as in the fertilizers which may be applied, will not be available to the acid-loving plants.
As soon as lime is used and well mixed with the soil, the acidity is neutralized, the reaction changed and the various plant food elements will form soluble compounds or soil solution readily available to the plants.
The accompanying chart illustrates this point. Although not strictly accurate chemically or in showing the relative proportion of the various elements, it should help to show how the availability of the nutrient elements changes with the soil reaction.
Best Levels of pH For Plant Nutrients?
Note: The greatest total of the desirable plant foods is available in the column between pH6 and pH7 or when the soil is slightly acid.
Therefore, the majority of our cultivated plants grow best in this range. The undesirable element, aluminum, is soluble only when the soil is very acid or very alkaline.
You will also note that the essential trace elements – boron, iron, manganese, copper and zinc — become unavailable when the soil is even slightly alkaline. This will emphasize the care that must be taken when applying lime. Too much may be as bad, or worse, than too little.
Amazing Activity in Soil
Few homeowners/gardeners are aware of the tremendous activity which is constantly going on in a good garden soil. Thanks to different soil-forming factors.
Earthworms are improving the soil texture; bacteria are breaking down complex compounds in the soil and in fertilizers, converting them into simpler forms available to the plants; beneficial fungi are making humus out of plant roots, compost and other plant debris.
In fact, hundreds of different kinds of minute plants and animals, called microorganisms, are working to improve the soil. A tablespoon of good garden soil may contain a billion of them. Incomprehensible? It certainly is; nevertheless, it is true.
The presence of these microorganisms in action means the difference between a “dead” and “live” soil. As the soil becomes more acid, it becomes impossible for these organisms to live.
Hence the presence of plant and animal remains, thousands of years old, in bogs. The lime application to acid soils changes the picture within a few months, by creating conditions favorable to plant growth and activity of beneficial organisms.
Testing Cucumbers – Possible Kids Science Experiment For Adding Lime
Here is an example helpful in visualizing the above: take two cucumbers, put one in a bottle of vinegar and the other in a bottle of ordinary, untreated drinking water, Within a few weeks, at a temperature above 75°, the cucumber in the water will be a shapeless mass of broken cells. The cucumber in the vinegar remains the same indefinitely. The acidity has killed the organisms in and around it.
For many years the value of lime through its calcium content has been widely known. However, it was mainly as a soil conditioner that the calcium served. As such, it neutralized lawn soil. For some time this was the only reason for using lime. It is still an important one, as previously described.
Over the years, soil experts have learned a great deal about the functions of the so-called “trace elements”. These are plant foods, such as boron, zinc, calcium, magnesium and others, which are used by plants in minute quantities.
The lack of any one of these, however, may be the deciding factor in the growth of plants. Both calcium and magnesium have been found to be essential to the growth of many plants.
Calcium is especially valuable in strengthening the cell walls of plants, much as it does the bones of animals and humans.
Magnesium is important in the synthesis of carbohydrates, fats and proteins, an essential constituent of chlorophyll and of help in producing good seeds.
Types Of Lime For Gardens
Various kinds of lime contain different percentages of calcium and magnesium. This should be stated on the bag or tag. It is because of its high magnesium content that the use of dolomite lime is used most often.
Here are other types of lime:
- Agricultural lime (agricultural limestone), also known as ag lime or garden lime
- Hydrated lime or calcium hydroxide, also known as bag lime
- Natural hydraulic lime
- Liquid lime
- Slaked Lime
- Dolomite Lime
- Pelletized lime
- Dolomitic lime – derived from deposits of calcium carbonate blended with magnesium carbonate.
- Calcitic lime – formed with deposits of calcium carbonate
One or more of the following benefits from the use of lime may be given by various authorities. However, I would suggest that their value is definitely limited under average conditions. In most cases, the lime would have to be applied in unusually heavy doses for the benefit to be effective.
Adding Lime May Improve Soil Texture
In clay soils, the fine particle sizes are stuck together into large units by certain properties in the lime. Thus a sort of “crumb” structure is formed, which provides better aeration and drainage.
Consequently, gardeners who have trouble with a heavy clay soil would be wise to use a soil conditioner for this purpose.
Adding lime also is of limited benefit in compacting sandy soils by adding its own fine particles to the sand particles, so making this type of soil more moisture-retaining.
Here, again the gardener would do better to depend upon some fine organic matter, silt or even clay.
Lime is of help in the control of garden pests. Lime, particularly the hydrated type, is very dusty, making it difficult for insects to breathe if they are covered with it or crawl through it.
However, road dust or some equally fine material might serve the purpose just as well. For many years lime was used extensively as a carrier for insecticides, but has since been replaced.
Lime is a good disinfectant. It is one of the oldest liming materials used by gardeners to control various diseases, both in the soil and on plants. Insofar as moisture is an important element in the inception and spread of diseases, and lime is helpful in drying this moisture, the lime itself might be considered beneficial.
Top 10 Liming Questions
How long does it take for lime to work?
Since water is required for lime to react with the soil, effects of a lime application will be slower in a dry soil. It often takes a year or more before a response can be measured even under perfect conditions. However, a response may be observed within weeks of the application when soil pH is extremely low. It is important to apply lime immediately after the growing season or crop removal to allow lime to react, correcting soil pH before the next growing season.
The reactivity time also depends on the type of lime used. Liming materials differ widely in their neutralizing powers due to variations in the percentage of calcium and/or magnesium. Usually, liming materials with a high calcium carbonate equivalent (CCE) tend to neutralize soil acidity faster than those with a low CCE. The coarseness of the liming material will also influence how fast the lime will react. In other words, the finer the liming material, the greater the surface area, resulting in faster reactivity.
How little or how much lime can be applied at one time?
The amount of lime needed depends on the type of crop being grown.
If growing continuous wheat or bermudagrass, it is only necessary to raise the soil pH above 5.5. Therefore, one-half ton or 25 percent of the soil test deficiency amount required to raise the soil pH to 6.8 is recommended. If growing legumes, the soil pH needs to be raised to 6.8. If surface applying lime, apply no more than two and one-half tons per acre per year. Up to four tons per acre may be applied if the lime is worked into the soil. In situations where soil pH is extremely low and a large amount of lime is recommended, it may be a good idea to spread the cost over two to three years by annually applying one-third or half of the lime needed.
Should lime be worked into the soil or placed on the surface?
Whenever possible, tillage should be used as a tool to incorporate lime into the soil. When lime is worked into the soil, a larger portion of its surface area is exposed to the soil allowing for faster reactivity.
Lime applied on the soil surface does not react as fast as lime incorporated by tillage, but what other option is there in perennial pasture systems? Surface-applied lime moves into the soil at a slow rate.
It is similar to non-mobile nutrients in its movement in the soil. However, there are a few crops that have roots that feed close to the soil surface, such as bermudagrass and alfalfa. It has been documented that correcting pH in the top two to three inches of the soil has a positive effect on forage production. Even though it is best to incorporate lime whenever possible, it is still important to surface-apply lime to correct the soil acidity problem in established pastureland and no-till cropping systems.
Does liming have an effect on herbicide activity?
There are several herbicide families that are soil pH dependent. For example, low soil pH levels may reduce the activity or residual time of triazine (atrazine, Sencor) and sulfonylurea (Peak) herbicides. High soil pH levels (>6.8) tend to increase herbicide activity that increases the risk of crop injury and/or carryover potential.
What effect do different tillage systems have on soil pH?
All lime calculations are based on neutralizing the acidity in the top six inches of soil. As a result, different tillage systems affect soil acidity. A conventional tillage system involves several tillage passes over the field prior to planting. If the subsoil is calcareous, deep tillage may mix enough subsoil into the top six inches to maintain soil pH at the surface. Conventional tillage systems allow the opportunity to thoroughly mix applied lime prior to the next growing season. A conservation tillage system is not as aggressive as conventional. Fewer tillage passes may be implemented prior to planting, leaving greater than 30 percent crop residue on the soil surface. As a result, there is a limited amount of soil mixing. It is critical to closely monitor soil pH in no-till systems since most lime and dry fertilizer is surface-applied. Over time, the top inch of soil may become extremely acidic due to the surface application of fertilizer. However, soil surface pH can also become too high if a large amount of lime is applied at one time and left on the soil surface. It is best to apply small amounts of lime more frequently to maintain soil pH in a no-till system.
Are dolomitic sources of lime better than calcitic?
In general, soils in Oklahoma and north Texas are not deficient in magnesium. Therefore, the use of dolomitic lime to increase soil magnesium levels is not important. Dolomitic lime may be recommended in pastures that have a history of grass tetany to raise forage magnesium levels. Both calcitic and dolomitic lime sources work well in raising soil pH. In our region, it is more important to look at the cost effectiveness rather than the source.
What are the advantages and disadvantages of liquid lime verses dry lime?
Liquid lime is a formulation of approximately 50 percent high quality dry Ag lime (usually greater than 90 percent) and 50 percent H2O. It has the advantage of providing better uniformity of spread over the field in comparison to dry lime. There are three main disadvantages of liquid lime. First, there are normally higher operational costs since you must haul both water and lime across the field. Secondly, under-liming is more likely to occur with liquid lime due to spread rate. Finally, more frequent lime applications are often needed since liquid lime reacts quicker than a dry lime source, but the rate may not be high enough to correct all the reserve acidity. One must be very careful of the rate at which liquid lime is applied. It is appealing to the producer because of its fast reaction time and uniformity advantages.
It is important to know how much active ingredient or neutralizing power that you are paying for.
What is the cost effectiveness of liquid lime products versus agricultural lime?
To make a decision about the cost effectiveness of these two products, one must compare both the total neutralizing power/unit weight of each and the cost/unit weight of each. This area can quickly become rather complicated.
If you have any questions in comparing the cost of liquid and dry lime, we would be more than glad to provide assistance.
Why is the difference in soil pH and buffer pH on the soil test report?
pH is an unbuffered measure of the hydrogen ion concentration in the soil (active acidity) whereas buffer pH is a measurement of total soil acidity (active + reserve acidity). Soils with low buffering capacities (low cation exchange capacity or CEC) usually have less total acidity than soils with a high CEC if the pH is the same. Therefore, it takes less lime to correct the total acidity in a soil with a low CEC. The buffer pH on the soil test report is used to calculate how much lime is needed to correct both the active and reserve acidity. When soil pH is 6.5 or greater, the buffer index will not be reported on the soil test report due to its irrelevance.
How often should I apply lime?
The answer to this question depends on a variety of considerations. A soil with a low CEC does not require a lot of lime to correct soil pH, but may need to be limed frequently. A soil with a high CEC requires a large amount of lime to initially correct pH, but it may be several years before another lime application is needed due to its high buffering capacity. The level of production also dictates how often lime will be needed. As fertilizer is applied to enhance forage or crop production, the removal of essential plant nutrients from the soil also increases. As a result, lime may be needed more frequently to replenish removed nutrients. For example, the rate of nutrient removal from a pasture being hayed is much greater than a pasture being grazed. Therefore, the hay field may need to be limed more often.
Adding Lime To Soil: What Does Lime Do For Soil & How Much Lime Does Soil Need
Does your soil need lime? The answer depends on the soil pH. Getting a soil test can help provide that information. Keep reading to find out when to add lime to the soil and how much to apply.
What Does Lime Do for Soil?
The two types of lime that gardeners should become familiar with are agricultural lime and dolomite lime. Both types of lime contain calcium, and dolomite lime also contains magnesium. Lime adds these two essential elements to the soil, but it is more commonly used to correct the soil pH.
Most plants prefer a pH between 5.5 and 6.5. If the pH is too high (alkaline) or too low (acidic), the plant can’t absorb the nutrients that are available in the soil. They develop symptoms of nutrient deficiency, such as pale leaves and stunted growth. Using lime for acidic soil raises the pH so that plant roots can absorb the necessary nutrients from the soil.
How Much Lime Does Soil Need?
The amount of lime your soil needs depends on the initial pH and the consistency of the soil. Without a good soil test, judging the amount of lime is a process of trial and error. A home pH test kit can tell you the acidity of the soil, but it doesn’t take the type of soil into consideration. The results of a soil analysis performed by a professional soil testing laboratory includes specific recommendations tailored to meet your soil’s needs.
Lawn grasses tolerate a pH of between 5.5 and 7.5. It takes 20 to 50 pounds of ground limestone per 1,000 square feet to correct a mildly acidic lawn. Strongly acidic or heavy clay soil may need as much as 100 pounds.
In small garden beds, you can estimate the amount of lime you need with the following information. These figures refer to the amount of finely ground limestone needed to raise the pH of 100 square feet of soil one point (for example, from 5.0 to 6.0).
- Sandy loam soil -5 pounds
- Medium loam soil – 7 pounds
- Heavy clay soil – 8 pounds
How and When to Add Lime
You’ll begin to see a measurable difference in the soil pH about four weeks after adding lime, but it can take six to 12 months for the lime to dissolve completely. You won’t see the full effect of adding lime to the soil until it is completely dissolved and incorporated into the soil.
For most gardeners, fall is a good time to add lime. Working lime into the soil in the fall gives it several months to dissolve before spring planting. To add lime to the soil, first prepare the bed by tilling or digging to a depth of 8 to 12 inches. Spread the lime evenly over the soil, and then rake it in to a depth of 2 inches.
FOOD PLOT DOCTOR
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About J. Wayne Fears
The Value of Liming Food Plots According to Soil Test Results
Why are my food plots yellow and not green like my neighbors? I have the same type of soil as my neighbor and I planted the seeds you recommended. My neighbor also kills more and better deer than I do. What’s going on?”
Not only is this one of the most frequent questions I get from Whitetails Unlimited readers but, as a food plot consultant, it is one the most frequent questions I get everywhere.
I usually start out answering the question with a question: “Did you use a soil test to determine if you needed to lime the plot, and determine the kind/amount of fertilizer you need to apply to the plot?” More often than not they come back with, “What is a soil test?” Then they tell me that when they planted their food plots they went to Wal-Mart and bought a few sacks of 10-10-10 fertilizer and put some on each plot. Sometimes I am told that they saved money and didn’t fertilize the plot at all because the dark soil looked fertile.
These are the wrong answers, and the reason many food plots fail to produce a healthy crop that will attract deer.
Liming Makes a Big Difference
A food plot such as this one, which has been limed and fertilized following instructions from a soil test lab report, will offer deer a maximum of tasty and nutritious food. Deer will seek it out!
Liming food plots, where necessary, is an affordable way to provide the elements necessary for optimum growth and nutrition of plants, which in turn benefits the deer that eat the plants. The need for lime, and if so, how much, is determined with a soil test that measures the concentration of hydrogen ions in the soil solution. This numerical measurement is called the pH of the soil. The pH range of a soil solution indicates whether it is acid, neutral, or alkaline.
The best way to determine the pH of a soil is to get a soil test. The laboratory analysis of your soil sample will tell you how much lime, if any, needs to be applied to the food plot. Also it will tell you how much of what mix of fertilizer the crop needs. If lime is needed, the soil analysis will tell you just how much you will need to apply so that you don’t create additional problems by having soil that is too alkaline.
Knowing the pH of a specific area of soil is vital to food plot production and the proper fertilization of foods growing in a deer habitat. A pH of 7.0 is neutral (neither acidic nor alkaline), while a soil pH below 7.0, such as 5.0, 5.5, 6.0, or 6.5 is acidic. Above the neutral measurement of 7.0, such as 7.5, 8.0, 8.5 and 9.0, is alkaline. Most deer forage crops grow best at pH values that are slightly acidic, between 5.8 and 6.5. Adjusting soil pH with lime within this range maximizes growth and increases yield, fertilizer efficiency, palatability of crops, and herbicide effectiveness. When a soil pH becomes too low for nutrients to be released for the food plot plants, it is necessary to apply lime to raise the pH to the desired level.
If lime is not applied properly to a food plot that has a low pH, an inferior crop will be the result. This is one of the chief causes of yellow looking food plot crops that get little utilization by deer. Lime is inexpensive and getting a soil test and following the recommendations for lime and fertilizer is one easy way to have a food plot crop that will attract and hold deer.
Lime should be applied about four months before the crop is planted. Lime is not water soluble and should be incorporated into the soil. A soil test should be done about every three years for food plots growing perennials and every two years for annuals.
In most areas where lime is required, a food plot may need one to three tons of lime per acre every other year, based on soil test results. Bulk lime may be purchased from many farm supply stores, delivered to your site, and spread on the food plot with a spreader truck for a range of $15 to $50 per ton, depending upon how near to lime quarries the store is located.
|Tools needed to take a soil test are a clean garden trowel, clean bucket, and soil test box or bag in which to send the soil test to the lab.|
One of the first questions I often get when a food plot owner realizes he needs to lime his plots, is, “Can I go to the garden supply store and just buy lime in 40 pound bags?” The short answer is “yes,” but what if your soil test results called for two tons of lime per acre? That would be 100 bags of pelletized bagged lime to buy at about $3.50 per bag, or $350 per acre. Then you’d have to load the bags on a truck, haul it to the food plot, unload it, and spread it. A lot of work! If you can get it in bulk you will be ahead of the game and the spreader truck or tractor-pulled spreader trailer will do a much better job of spreading lime evenly.
The only time I have used bags of lime has been on very small food plots in locations so remote I couldn’t get a truck or tractor spreader to them. An ATV can usually be used in these situations.
How to Take a Soil Sample
Proper collection of soil samples is extremely important. The results of this test will tell you how to fertilize and lime the ground for proper balance of nutrients and optimum soil pH level. Time and money are saved when you apply only the amount of fertilizer needed. Over-fertilization wastes your or your hunting club’s money, and may even cause harm to plant materials. Here is how to take a soil sample:
Most soil test kits include a box to put each food plot soil sample in, and a place to provide information about the sample.
Go to your local county agent’s office (Cooperative Extension Service) and get a soil test kit. There is a Cooperative Extension Service office in most county seats. The kit will consist of soil sample bags or boxes, information sheets, and a shipping box. Do-it-yourself soil test kits may also be purchased from garden supply stores.
- Get the tools you will need to take the samples – a clean bucket and a clean garden trowel, spade, or soil probe.
- Following the information given in the soil test kit directions, go to 20 or more sites in each food plot to take samples. One pint of soil is needed for analysis.
- At each sample site in the food plot, scrape off any plant material from the soil surface. Push the trowel into the soil 3-4 inches deep.
- Discard the soil and cut a one-inch slice from the back of the hole. Place the slice in the bucket. Do this at each sample site.
- When all the samples in the food plot are collected, thoroughly mix the slices. Air dry the samples overnight on a flat surface lined with clean white paper. Pour the sample into the sample bag or box.
- Fill out the bag or box with the specified information. Be sure to give each food plot an identification number or name, and keep a record so the recommendation you receive from the soil lab can be associated with the food plot from which the sample came.
- Send the sample to the state testing lab listed in the kit instructions. A small fee, around $10, is usually charged. Although some large farm supply stores provide free soil tests to their customers.
- Your soil test results provide lime, nitrogen (N), phosphorous (P), and potassium (K) recommendations for your particular food plot plant varieties.
Follow the recommendations to the letter. If you have any questions about soil testing, ask your county agent. Their service is free, and it can help you have outstanding food plots.
Deer know the difference between “cheap hamburger” and “prime steak.” A food plot planted following the recommendations of a current soil test is prime steak.
It takes 20 samples, mixed and dried, from a food plot to get a good sample mix to send to a soils lab. This simple illustration shows the pattern to walk and take soil samples in a food plot.
J. Wayne Fears, the Food Plot Doctor, is one of the pioneers who helped develop food plot practices that are common today. Now, his decades of experience are available to Whitetails Unlimited members. J. Wayne uses questions from our readers as the basis for his column as the Food Plot Doctor. Just email your questions to . The Food Plot Doctor columns will be archived on the WTU website, so you can go back to them for reference in the future.
Unfortunately, J. Wayne will not be able to respond to emails individually, but will find common themes from your questions to write about. So get busy, find that thing that’s been driving you crazy, or that one topic on which everyone else seems to have directly opposite opinions, and let J. Wayne give you the straight scoop.
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