Nutrient Management Strategies

Abstract

Large dairies on relatively small land bases are rich in nutrients, which sometimes accumulate in excess of crop use. Twenty-six silage corn fields in the Willamette Valley, Oregon were sampled over a 2-yr period. Soils at approximately 40% of the sites contained NO3 N in excess of crop need. Excess amounts of P and K were measured from the same fields. Unused plant nutrients can be potential pollutants or animal health risks. Nutrient accumulation on dairy farms can be reduced by eliminating or reducing commercial fertilizer and reducing the net accumulation of on-farm nutrients from purchased feed. Each dairy should produce as much of its feed as possible to reduce the importation of nutrients in feed and the cost of purchased feed. Dairy producers must match plant nutrient need and uptake with crop growth and distribute nutrients on land as needed. A program of monitoring nutrient need and sufficiency through analysis of manure, soil, and plant tissue allows nutrient distribution to be matched to crop need.