Editor’s note: Reinder Prins is a contributing writer for AgriBusinessGlobal.com’s sister site, PrecisionAg.com, which is where the following article originally appeared.
Harvest is progressing across most parts of the U.S. and those growers who aren’t already harvesting are gearing up to start soon. In a few months, the crops will have been harvested, the fields will be bare, and the equipment will be serviced and stored away ready for next year’s harvest. This is also the time of year when growers and their advisors turn their attention to “servicing” their soil in preparation for the new crop. Different processes and procedures exist, but most co-ops and agronomists will work with their client to get soil samples analyzed and then create a fertilizer strategy that fits with the agronomic and financial plan.
So, what are these fertilizer strategies actually based on? Every agronomist will have a slightly different answer but in many cases, the strategy simply aims to close the gap between the nutrients that are currently available in the soil and the nutrients next year’s crop is expected to need. This approach to replacing nutrients based on expected crop removal certainly improves on the historic non-scientific blanket applications and continues to gain popularity as new research combined with better technology improves our understanding of the factors affecting plant nutrition. One aspect of most nutrition strategies that has stayed the same is the fact that fertilizer costs are the number one input cost for most growers. But should it be?
I recently had a very interesting discussion with a grower who told me about his journey to understand and formulate his own fertilizer strategy. His process identified more than 300 soil sampling sites on his farm which are analyzed regularly with the results able to be viewed in the context of other data layers including soil type, yield data, and NDVI imagery. With 10 years’ worth of data available, he can now easily identify trends, anomalies, and other changes in his soil. In addition to a cropping agronomist, this grower also employs the services of a soil consultant to help drive the science behind the process. Good data enables good insights and by combining the multiple layers of data he was able to determine that by marginally increasing the pH of this soil, he was able to increase the availability of phosphorus already present in his soil and subsequently reduce his fertilizer bill on a proportion of his fields.