Nitrogen losses from farm runoff under simulated rainfall conditions

Abstract

Rainfall simulation experiment was performed to evaluate nitrogen losses from farmland and show the effect of fertilizer application on nitrogen concentration and losses of runoff. As expected, cumulative N loss of runoff is directly correlated with cumulative runoff; dissolve nitrogen concentration and the dissolve nitrogen lost significantly increase (P=0.01), but particulate nitrogen concentration and particulate nitrogen lost do not significantly increase (P=0.1) in farmland runoff of fertilizer application of NH4HCO3. Particulate nitrogen lost account for 476.3~488.7 mg/m2, and particulate nitrogen is the main form of N losses. Nutrient of N is enriched in eroded sediment, the logarithm of N enrichment ratio (ER) is negatively correlated with the logarithm of accumulated sediment discharge: log(ER)=0.770-0.300 log(SED).