Summary

Both N and P are needed by plants in large amounts, but when soils are too rich in these nutrients, they are environmental hazards. And although N and P behave differently in soils, most sound management practices for one are also sound for the other. Using soil tests (and for N on corn the end-of-season lower stalk nitrate test) and modern nutrient management planning that credits all sources, such as manures and decomposing sods, can help better manage these nutrients. Reduced tillage, cover crops, and rotation with sod crops decrease runoff and erosion and help in many other ways, including better N and P management.

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