Nutrient losses through tile drains under three cropping systems and two fertility levels on a Brookston clay soil.

Plant nutrient losses were measured in tile drainage effluent from three cropping systems on a Brookston clay soil over a 7-year period. Highest losses of N, P and K occurred with corn and lowest with bluegrass sod. Additions of N-P-K increased average losses of N, P, K, Ca and Mg. Nutrient concentration in drainage effluent varied with season with N, P, K and Ca concentration tending to be lower in the spring. The amount of water that flowed through the soil of a particular cropping system was the predominant factor influencing nutrient loss.