AG  LIME

Our ag lime is a high quality product derived from water treatment plants. Over the years Valley Ag Supply has learned how to process this source of lime to get it to the right moisture content so that it can be effectively and accurately spread on our customer’s fields.

What is Ag Lime and What are the Different Sources of Lime?

Ag Lime is calcium carbonate. There are a few different forms and sources of lime and each one of them has their pros and cons. 
  • Pelletized lime (98G). This form of lime is commonly used because of its ease of use. Because it is in a pelletized form it fits in well with fertilizer operations and doesn’t require any additional special equipment to apply the product. Although you will see a great initial response with your crops from applying this product, it can be very expensive and in most cases does not effectively correct the pH issues in the soil for a long term result.

  • Ag lime can be mined out of the ground in a quarry. This is a great source of lime, but it is a lot more course, therefore it will take longer to take effect in the field (2-3 years before you start seeing a result with your crops). In the end it will be the same as Valley Ag Supply’s ag lime, but will take longer to get the results you want. The product itself is cheaper, but unless you live close to a quarry, it will be more expensive once you ship the product to your farm.

  • Water treatment plant lime. Ag lime that comes from water treatment plants is a great source of ag lime. Generally there will be a water treatment plant closer to your farm than there will be a lime quarry. However, the lime that comes out of a water treatment plant is a wet sludge (40% to 50% moisture) that is not easy to handle. Most places don’t want to handle this form of lime because they don’t have the equipment necessary to dig the lime out of the pits and spread it on the fields, or the time to let it dry. Lime that is applied to fields as this wet sludge will not get an even spread across the field. Lime will only correct the pH in the soil that it comes in contact with, so if you have globs of wet lime in your field it will only be correcting the pH in those areas and not evenly across the field.
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  • Liquid Calcium. This is not a form of lime, but we want to bring it up so that you can be cautious when researching these products. While some of these products may be good, a lot of them like to compare it to ag lime, which is not a fair comparison. Just because a product contains calcium does not make it a good liming material. Lime needs to be able to effectively remove the hydrogen ions from the soil in order to change the pH in the soil. Most of these liquid calcium products are a form of Calcium Chloride and not Calcium Carbonate. So these liquid calcium products will show a good response in your field because calcium is a nutrient that your crops need. However, they are not going to do the same thing in your soil as ag lime to remove hydrogen ions and increase the pH in the soil. They also talk about how much cheaper their product is compared to ag lime, but once you do the math, you’ll find out that in the long run it will be more expensive. One source said it would cost about $10/acre for a liquid calcium product. Let’s just use this for an example. If you just look at this price for the first year, then yes, it looks like liquid calcium is way cheaper than ag lime. However, liquid calcium will have to be applied each year and ag lime will only have to be applied once and then maintained with a lesser amount every 10 years. So over the course of 10 years you will have spent more money on liquid calcium than ag lime and still not have corrected the issue of low pH in the soil.

Why is Valley Ag Supply's Ag Lime Better?

Valley Ag Supply’s lime is derived from local water treatment plants. Over the years we have learned how to process this source of lime by drying it down to the right moisture content so it can be effectively and accurately spread on our customer’s fields. The reason for using lime from water treatment plants is because it is a local source, it contains a few micronutrients from the water treatment plant process, there are no heavy metals, and the end result is a fine, powdered product. For ag lime, the finer the product the better. Our lime is very fine, yet leaving the right amount of moisture in the product so it will spread accurately across the field.  
The raw product after it has been dug out from the water treatment plant lagoons needs to be processed in order for it to become a usable product 
After being processed, the finished product is much finer and dryer. It is piled and then ready for shipment to producer's fields. 

How Does Ag Lime Work?

It’s all about understanding the chemistry in your soil.

           CaCO3 + H+ = H2O + CO2 + Ca

In case you don’t remember this from your chemistry class or can’t find your books, let me explain. Lime is Calcium Carbonate (CaCO3) and having a low pH (acidic) in your soil is a result of positive hydrogen ions (H+). When ag lime is applied to the soil, it will react to these positive hydrogen ions to produce water (H2O), Carbon dioxide (CO2), and Calcium (Ca). Getting rid of the positive hydrogen ions in the soil will result in raising the pH of the soil. Water, Carbon dioxide and Calcium will be used by the plant and the Calcium will also help open up the soil structure.

Lime is not water soluble in the soil; therefore it will stay in the soil structure and react with what it comes in contact with. Working the lime into the ground will allow it to come in contact with more of the soil. If applied to a no-till field or to an existing alfalfa field, then it is recommended to start with a half rate followed by the other half rate a year or two later. This will allow the lime to naturally work its way through the soil structure and prevent the top three inches of the soil structure from over correcting the pH while not changing the pH of the soil below. Adding gypsum (calcium sulfate) at the same time will also help with the lime being able to move into the soil structure in a no-till or alfalfa field. The calcium in gypsum will help open up the soil structure and it is very water soluble. 

Why Would I Need Ag Lime on my Field?

Not every field or even every acre of your field needs lime. However, if you have soil test results that come back with a low pH, then lime is needed to correct that issue. Crops will grow in a wide range of pH, but they won’t do nearly as well as when the pH is in that optimal range of 6.5 to 7.0 for corn and soybean production. Correcting a low pH issue in your field will result in more nutrients to be available to the plant to use and an increase in yield. In addition, lime from water treatment plants will contain some micronutrients that can be a bonus for your crops.  

What are the Benefits to Applying Ag Lime?

  • Correcting a low pH issue in your field.
  • Increased yields.
  • Increased nutrient availability in your soil.
  • Increased microorganism activity
  • A sense of pride and accomplishment knowing that you are taking care of your land to ensure that it will be productive for many years to come and it will be in better shape for the next generation of farmers in your family. 

How Much Ag Lime do I Need?

The amount of lime needed will vary depending on the pH of the soil. This will vary from field to field and also from acre to acre within one field. Applying that correct amount of ag lime to the right part of the field is critical. Applying too much ag lime can result in over correcting and raising the pH above the optimal range. If this happens there is nothing that can be applied to bring the pH back down. Fields must first be grid sampled before applying lime so you know you are applying the right amount where it is needed in each field. Talk to an agronomist at Valley Ag Supply to have them help you figure out how much, if any, lime is needed on your operation.  
The two maps (below) depict images of the same field. The map on the left, is a soil sample grid map and it shows the different pH levels in the field. The map on the right is an ag lime recommendation map. It shows the areas in the field that need ag lime and at what rate. You can see a large portion of the field calls for no ag lime to be spread.
We have plenty of data to show the formula we use for our ag lime works in our area. To most of you this formula will look Greek and that is okay. The only thing that you’ll need to understand is that there is a reason and a mathematical formula behind why we recommend a certain amount of lime to be applied. But for those not in our trade area and looking to spread ag lime themselves, then this formula will be important to understand along with the explanation of what we have learned and why. With all of this information though, we recommend that you use this as a starting point and would still encourage you to do your own tests to fine tune your recommendations based on data from your area.

Valley Ag Supply Base Lime Formula
[ph] >= 6.5 : 0
([ph] < 6.5) and ((6.5 – [BpH]*5) < 5) : ((6.5 – [BpH])*5)*2000/0.900
([pH] < 6.5) and ((6.5 – [BpH]*5) > 5) : 5*2000/0.900
  
The formula that Valley Ag supply uses to determine how much ag lime to apply to a Corn/Soybean rotation field comes directly from Midwest Labs. The 0.9 factor at the end of the formula is the recommendation from Midwest Labs, that even the highest quality lime is 90% effective. With most ag lime, you would then need to factor in the ag lime’s ECCE off of the analysis, on top of this base formula. (Basically, if the ag lime’s analysis has an ECCE of 60%, then it is only 60% effective, and will require that more pounds be spread on the field to get the results that you want.) However, with our ag lime, we do not take into consideration the ECCE and only use the base formula. The reason we do this is because our lime is in a powdered form and very fine. The finer the product, the more surface area it has to react with the soil and therefore more effective. Part of the equation for calculating the ECCE is the fineness factor. Different areas of the country have different requirements of how to calculate this fineness factor (so pay attention that you are comparing apples to apples if you are looking at recommendations from different universities). But with all these formulas, the one thing that they have in common is the fineness mesh screen that they use in their calculations is a 60 mesh screen. And since more than 90% of our ag lime can pass through a 100 mesh screen our lime is basically more effective than what the formula says. In our area we have seen the soil pH move from a 5.8 to a 6.8 by using only the base formula for a recommendation.

These recommendations are for a full rate based on incorporating the ag lime into the soil. If applying our ag lime to a no-till field or to an existing alfalfa field, then it is recommended to start with a half rate followed by the other half rate a year or two later. This will allow the lime to naturally work its way through the soil structure and prevent the top three inches of the soil structure from over correcting the pH while not changing the pH of the soil below. Adding gypsum (calcium sulfate) at the same time will also help with the lime being able to move into the soil structure in a no-till or alfalfa field. The calcium in gypsum will help open up the soil structure and it is very water soluble.   

When Should I Apply Ag Lime?

It is recommended that ag lime be applied in the fall after harvest but before any tillage. This will allow you to work the ag lime into the ground to get it in contact with as much of the soil as possible and give it time to work so you will see the benefits during the next season. Most importantly, though, it is to mitigate the amount of compaction in the field. Because of the amount of ag lime that generally needs to be applied, the equipment needs to go across the field more than usual. Spreading the ag lime in the fall will allow for the natural freezing and thawing of the winter months to remove the compaction. If you spread the ag lime in the spring, the benefits from the lime will be offset by the compaction for the first year. There are some exceptions to the rule, such as if you have sandy soils. But then again, you or Valley Ag Supply may not have time to apply it before the fields need to be planted.

Spreading our ag lime in the winter can work if there is no snow on the ground. Compaction is not an issue due to the frozen ground, but spreading the lime can be a bit more of a challenge for the crew at Valley Ag because the lime will freeze as well (being that it is 25% moisture). A challenge, but not impossible.

How Much Does It Cost?

This is the biggest question that everyone has and ultimately the biggest hang up as well.

One way to describe it is “sticker shock.” Yes, people are taken back at first when they see that it will cost anywhere from $50 to $100+/acre to apply ag lime on their field. But let’s not stop reading this and catch our breath for a moment. Let’s look past this initial “price” and look at the big picture. We need to look at this as an investment. An investment in your soil to ensure that it will produce to its full capacity for years to come. Yes, you will have to pay a lot initially, but once you apply it, you won’t have to come back to put more ag lime on for another 5 to 10 years. And when you do have to apply it again, it won’t be at the same initial quantity, only enough to maintain that optimal pH.

Here are some ways to help manage the cost of applying lime.

  • During the first year, you may not have to put as much fertilizer on your field because the lime will free up nutrients already in your soil and make them available for the plants to use. When you don’t apply lime where it is needed, you can end up throwing away a lot more money in fertilizer. It won’t matter how much fertilizer you spread, it won’t be available to the crops if your pH is low.
  • Apply only one or two fields a year. Start reaping the benefits from those fields and putting that money towards applying lime on the rest of your fields.
  • Apply a half rate at first. You will get the most ‘bang for your buck’ out of that first half of the lime recommendation. Your yields will benefit from even a half rate and then you can come back in a year or two to spread the other half rate to fine tune your pH and get it to where it needs to be.
  • Look at it as a long term investment. $100/acre is a lot to spend, but when you spread that over the course of 10 years, then $10/acre/year doesn’t seem as bad.
  • We have university data and local testimonials that shows how lime investments will pay back in two to three years.
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Talk with any of the agronomists at Valley Ag Supply to have them come up with a solution that will best fit your operation to optimize your potential without breaking the bank. 

What if I am not in Valley Ag Supply's Trade Area?

Not to worry. Valley Ag Supply wholesales their lime to other coops and agronomy centers. Call Cody at the Valley Ag Supply office 605-267-3100 to find a retailer near you that has the capabilities to spread our ag lime.

If you are a coop/agronomy retailer looking for a source of ag lime, call Cody at the Valley Ag Supply office 605-267-3100 to find out if our ag lime will fit into your operation.