水蚀条件下硝酸铵施用对黄绵土氮素流失的影响

研究结果表明不同坡度谷子地 ,高 N处理小区径流中铵态氮、硝态氮和有效氮浓度平均为 1.0 6、0 .76和1.82 mg/kg,低 N分别为 0 .6 4、1.2 9和 1.93mg/kg;高氮处理土壤铵态氮、硝态氮和有效氮平均流失量分别达到17.90、12 .93和 30 .84kg/(km2 · a) ,低 N流失量为 11.90、2 3.86和 35 .77kg/(km2 · a)。高氮处理小区泥沙中有机质和全氮浓度平均为 5 .2 1和 0 .5 36 g/kg,而低氮处理分别为 4.94和 0 .481g/kg;高氮和低氮处理土壤有机质流失量分别为 5 70 2和 5 743kg/(km2 · a) ,土壤全氮流失量为 498和 5 5 9kg/(km2 · a)

The millets fertilizing NH 4NO 3 with high N(NH 4NO 3 500 kg/hm 2) and low N(NH 4NO 3 250 kg/hm 2), are planted in the slope lands with 10°, 20°, 25°and 30° slope gradient. The research results were as follows: The mean concentrations of NH + 4 N, NO 3 N and NH + 4+NO 3 in runoff were 1 06, 0 76, and 1 82 mg/kg in high N treatment (HNT), and 0 64, 1 29, 1 93 mg/kg in low N treatment (LNT) respectively. The loss amounts of them in runoff were 17 90, 12 93, and 30 84 kg/(km 2...