Winter Application of Phosphorus and Potassium to Farms
The following appeared in the January 26, 2010 edition of the CORN Newsletter:
A lot of fertilizer has been going on fields in the last couple of weeks, and though it is certainly not an optimal time, there is one advantage to application now with the wet autumn in 2009: compaction is minimized on frozen soils compared to saturated ones. However, just like manure applications on frozen or snow-covered ground, the possibility of commercial fertilizers moving off-site in runoff increases greatly when P and K do not migrate into the soil profile (perhaps more so since commercial P and K sources are water soluble by design). Environmental concerns notwithstanding, fertilizer inputs are a significant part of a crop enterprise budget, and losses from the field equate to losses on a balance sheet.
Consider if an application of P and K to particular fields is even necessary by checking a recent soil test against the Tri State Fertilizer Recommendations for the planned crop and crop rotation. Also strongly consider an application setback from sensitive areas (ditches, waterways, streams, etc.) of at least 200 ft, especially on sloping land where surface movement is accelerated. For more information, there is an Extension Fact Sheet on phosphorus best management practices available online: http://ohioline.osu.edu/agf-fact/pdf/0509.pdf.
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