Last week we discussed how to use your technology tools to improve water quality.
When it comes to phosphorus, are you using representative soil tests to determine crop needs in specific areas of fields? Are you then following these tests with variable rate application? This likely will require you to work with someone who can help you decide the best method for breaking your field down in to management areas (stay tuned for another blog on this topic). This service provider will also be responsible to produce the electronic data needed to first sample and then apply the required materials.
The other question to think about in phosphorus management is application timing and material placement. Phosphorus is an element that is picked up by plants through the root system. This makes concentrating the material in a band where the roots are going to find it an attractive option. As planters get larger, starter fertilizer equipment becomes a management issue. However, this may be your most attractive option for maximum phosphorus efficiency for your corn crop.
Timing is also an issue. Because of the tight windows for broadcast applications in the fall, there is a great deal of fertilizer put on after ground is frozen. This makes fertilizer vulnerable to runoff. This not only weakens your investment in fertilizer, but it also contributes to phosphorus in the watershed.
I also question if values we use to determine phosphorus requirements from soil tests are still valid. I am sure that the per bushel removal rates are mostly accurate; however, I wonder if the advances in plant breeding have given our corn plants bigger and better root systems that have enhanced their ability to recover nutrients we apply. The critical values were determined, in most cases, many years before plant breeding truly became the science it is today.
Nitrogen management is a harder nut to crack. This is primarily due to its ability to move with water. Too much water and you have a shortage, as it has likely left the soil profile. Too little water and the element is there, it just can't get to the plant roots. Throw in soil type and soil life and the puzzle becomes more complex.
The opportunity for variable management of this nutrient is to look at the soil's ability to provide organic nitrogen. Developing the right zone management area is the key to variable rate nitrogen.
All of this is an opportunity for you to leverage your technology tools. If you work with someone to develop a plot system of replicated treatments you can use your variable rate equipment and yield monitor to evaluate and develop your own critical nutrient levels. The NRCS is looking into "Adaptive Management" and appears to be developing a program that would provide incentive payments to promote these types of innovative management practices.
Use your tools to be proactive and help develop the data sets required to determine the right rates of these critical elements. Put these practices in place now and you'll be a step ahead if the practices become regulated. If we as a collective community can create the needed valid data, we will be invited to the table when regulations are being determined.
Ultimately we are going to be required to produce maximum output while minimizing our environmental footprint. Luckily for us minimizing our environmental impact will actually be synonymous with maximizing efficiency, and eventually, profitability.