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IA/MN/WI | This is true, but it doesn't affect soils of moderate CEC in a measurable way. It very well could play a role for your area Moose with the sandy loam textured ground that shows up in west central WI and east central MN. But the soil shown by the OP has soil with relatively strong CEC. With his soil type 30" of rain would only move Potassium 1-3inches, but most of that movement would be contained to the K located in the top 4inches of soil, once you go below that leaching is greatly reduced. Phosphorous would be of little concern as it barely leaches and mostly moves laterally in the soil, Sulfur is quite leachable, but it also mineralizes well. If he is applying 20-30lbs of S(depending on yield goals) via ATS, Elemental, or Gypsum I doubt he is going to have any real issues with those levels.
Should the OP apply synthetic fert this year? That's up to him, but all data would suggest that he could grow corn for a number of years without commercial Phos and be more profitable. He certainly could skip potassium for a year or two if desired, after that I'd be checking soil levels.
We routinely grow 225-275bu corn on fields with P levels that are 15-22ppm and K levels that are 120-130ppm. | |
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24 inch soil samples
