Fertilizer applications, nitrate loading patterns, water resources quality and their ecotoxicological implications in Awka area of Nigeria

Abstract

Nitrogen fertilizer applications at the mean rate of 500 kg ha−1 nitrogen–phosphorus–potassium, 280 kg ha−1 urea, and 200 kg ha−1 calcium ammonium nitrate reported for the year 1990 in the Awka area of Nigeria exceeded the recommended doses for the region. An inestimable amount of these are unabsorbed by plants and are leached as soluble nitrates into surface and groundwater environments. © 1994 by John Wiley & Sons, Inc..