Leaching characteristics of nitrogen and phosphorus in inorganic compound fertilizer from latosolic red soil in South China.
华南赤红壤无机复合肥氮磷淋失特征

A soil column experiment was conducted to investigate the leaching characteristics of nitrogen and phosphorus in inorganic compound fertilizer from latosolic red soil in South China. The results revealed that the leaching loss of soil total nitrogen (TN), NH4+ -N and NO3-N was increased with increasing application rate of inorganic compound fertilizer, and 36.8%-49.2% of fertilizer nitrogen was lost with leaching water. The regression equation of TN loss (y) and N application rate (x) was y = 0. 3667x + 66. 483 (R2 = 0.992). TN and NH4+ -N losses mainly occurred in the first 5 leaching events, while NO3- -N loss continued to be significant till the 9th leaching event. Fertilization rate had no obvious impact on soil dissolved phosphorus (DP), but the leaching loss of total phosphorus (TP) and particulate phosphorus (PP) was increased with increasing fertilization rate. The fertilizer phosphorus loss was within the range of 0.002%-0.01%, and the regression equation of TP loss (y) and P application rate (x) was y = 7e(-5)x + 0.0538 (R2 = 0.931). Quite different from that of N, the leaching loss of P was a slow and continuous process. Both the leaching loss of NO3- -N / NH4+ -N and of DP/PP was decreased with increasing fertilization rate.