长期施肥对红壤旱地剖面硝态氮累积的影响

研究了长达18a长期不同施肥处理下红壤旱地剖面中NO3--N分布和累积的特征。结果表明：施用化肥的处理中，磷肥和有机肥料的施用能显著降低N03--N在0-100cm土体中的积累（P〈0．05）；不同施肥处理（除氮钾处理），均在40-60cm之间形成NO3--N累积层，氮钾配施的旱地土壤20～40cm层中NO3--N峰值最高达70．72mg／kg；各施肥处理NO3--N残留率在0．69％～8．31％之间，有机肥的施用能显著降低NO3--N在0-100cm土体中的残留（P〈0．05）。

Effects of Long-term Fertilization on Accumulation of NO_3~--N in Profile of Red Soil Dry Land

Effects of Long-term (18 years) different fertilization on distribution and accumulation of NO_3~--N in profile of red soil dry land were studied. The results showed that the applications of organic fertilizer and phosphate fertilizer could reduce the accumulation of NO_3~--N in the 0 to 100 cm soil layers significantly (P＜0.05); the NO_3~--N, which under different fertilizer treatments (except the treatments of nitrogen and kalium), could be accumulated in 40 to 60 cm soil layers, and the highest peak value of NO_3~--N reached 70.72 mg/kg in 20 to 40 cm soil layers of dry land with combined application of nitrogen fertilizer and kalium fertilizer, the residual ratio of NO~(3-)-N in soil under different fertilizationtreatments was from 0.69% to 8.31%; the application of organic manure could reduce the residue of NO_3~--N in the 0 to 100 cm soil significantly (P ＜0.05).