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Darin Lickfeldt, Ph.D., CCA, was a technical development manager with Verdesian Life Sciences and an expert on nutrient use efficiency. Dr. Lickfeldt recently answered questions about the benefits of adding AVAIL® Phosphorus Fertilizer Enhancer to your nutrient management program.

Q: Why is it just as important for farmers to manage their phosphorus investment as it is their nitrogen? 
Dr. Lickfeldt: Both phosphorus and nitrogen are critically important to the plant, but each carries out distinctly different functions. Phosphorus is especially important for root growth, which is a key indicator of overall plant health. Just about every cellular and biological pathway within the plant relies on phosphorus to some degree. If you end up phosphorus deficient, those critical plant processes are going to suffer.

Q: Why should a farmer consider using AVAIL® Phosphorus Fertilizer Enhancer?
Dr. Lickfeldt: People believe that phosphorus behaves the same as nitrogen in the soil, when nothing could be further from the truth. Nitrogen is very mobile, while phosphorus is not. That immobility is good from the aspect that the farmer won’t lose the applied phosphorus, but the nutrient isn’t doing any good if the plant can’t access it. AVAIL grabs onto positively charged cations in the soil and thereby protects the phosphorous from being fixed by other elements in the soil, keeping more P available for the plant to use.

Q: How does AVAIL work to prevent fixation of phosphorus in the soil? 
Dr. Lickfeldt: AVAIL is an additive that surrounds applied phosphorus fertilizer in a water-soluble shield, which prevents it from being fixed by other elements in the soil. This leaves more of your applied phosphorous available for the plants to utilize. Think of it like a fullback leading ahead of a tailback in a football game. AVAIL is the fullback blocking outside tacklers from inhibiting the tailback, or your applied phosphorus. To keep your phosphorus available for plant uptake, you can’t have it tackled or stopped. AVAIL works to keep the applied phosphorus available for your plants.

Q: What research has been done on AVAIL to prove its effectiveness?
Dr. Lickfeldt: More than 59 million acres of farmland have been treated with AVAIL, and generally we’re seeing an 7-11 Bu./A improvement versus plots not treated with AVAIL in replicated trials (please verify these numbers before publishing). AVAIL has also been on the market for 10 years now, so we have a lot of experience with the product and have a high level of confidence with it. A common concern I hear from folks is that AVAIL is fairly new and untested, but after 10 years and 59 million acres, we’re very confident with the product and the benefits it provides. Adding AVAIL can provide a great return on your fertilizer investment.

Q: What soil types will benefit most from the use of AVAIL? 
Dr. Lickfeldt: Across the U.S., soil types growing row crops vary tremendously. Where we see AVAIL make the greatest impact are those acres that are somewhat phosphorus deficient, 20 parts per million or lower and with pH below 6 or above 7. That’s where you’ll see the greatest return on your investment. But on the other hand, if you have a field with a high level of organic matter, say 30 parts per million or greater, you may have a situation where your phosphorus isn’t available for uptake in the plant. AVAIL can increase the availability of soil applied phosphorus even in higher P test soils. So whether your soil has high or low levels of phosphorus, we have seen a positive response and significant return on investment with AVAIL. It’s important to remember that just because soil tests might indicate high phosphorus levels, that doesn’t mean that phosphorus is working for you in terms of plant nutrition.

Q: What are relevant crops for which AVAIL-treated phosphorus may be applied?
Dr. Lickfeldt: Phosphorus fixation is an issue that occurs in the soil, not a problem within the plant. So AVAIL is effective on all crops, in any soil and in any climate. However, if you want to focus more narrowly on the biggest commercial crops in the U.S., corn, soybeans and wheat, we have seen a great response to AVAIL in all three. But at the end of the day, all plants rely on phosphorus, and they will suffer the same consequences if they are phosphorus-deficient. AVAIL on treated fertilizer can make more phosphorus available, no matter what crop you are planting.

Q: What are the application options for AVAIL? 
Dr. Lickfeldt: AVAIL comes in formulations for both liquid and dry fertilizers. Our liquid formulation can go directly into a spray tank for those that use liquid fertilizers. Our dry formulation is applied to fertilizer granules before they are applied to the soil. So however you chose to apply your fertilizers, AVAIL can be easily worked into your nutrient management plan.

Q: Is fall or spring application preferable when using AVAIL?
Dr. Lickfeldt: University and third-party independent research shows that AVAIL-treated phosphorus is just as effective applied in the fall as it is in the spring. Personally, I like a spring application better and typically recommend applying any nutrients closer to when the plant is going to need them. But phosphorous can be applied in both spring and fall, so the addition of AVAIL at either time is going to produce a nice return on investment.

AVAIL is proven to provide protection against applied phosphorous fixation in the soil. To learn more about AVAIL, and the broad product profile that Verdesian offers, visit

Important: Always read and follow label use directions.

AVAIL is a registered trademark of Verdesian Life Sciences.