肥料混施对赤红壤氮磷淋失特征的影响

采用室内模拟土柱淋洗方法研究了无机复合肥、有机复合肥、猪粪堆肥和花生麸4种肥料单施和两两混施条件下氮磷在赤红壤中的淋失特征。结果表明,各处理总氮淋失率在43.2%～74.8%之间,总磷淋失率在0.01%～0.08%之间,赤红壤中肥料氮淋失严重,肥料磷淋失有限。肥料单施处理的无机氮淋失量和有机氮基本相近,肥料混施处理的无机氮淋失量远高于有机氮;各施肥处理磷的淋失均以颗粒磷为主。肥料混施显著增加铵态氮和无机氮淋失,减少有机氮和总氮淋失。猪粪与复合肥混施减少颗粒磷和总磷淋失,花生麸与复合肥混施则促进颗粒磷和总磷淋失,所有混施处理均减少可溶性磷淋失。肥料混施对赤红壤氮磷淋失特征具有显著的混施效应。

Effects of Combined Fertilization on the Leachng Regimes of Nitrogen and Phosphorus in Latosolic Red Soil

A soil column experiment was conducted to investigate leaching regimes of nitrogen (N) and phos- phorus (P) from four fertilizers,i.e.,organic compound fertilizer,inorganic compound fertilizer,pig ma- nure compost and peanut cake applied individually and in combination in latosolic red soils of South China. Results showed that leaching loss rates of fertilizer N ranged from 43.2% to 74.8% and those of fertilizer P ranged from 0.01% to 0.08%,exhibiting severe leaching loss of N and marginal leaching loss of P in latosol- ic red soils in South China.Leaching loss amounts of inorganic N were similar to those of organic N in the treatments where fertilizer was individually applied,but higher than those of organic N in the treatments where fertilizers were applied in couple.Particulate P (PP) was the main form of phosphorus leaching loss in all the treatments.The combined application of two fertilizers increased leaching loss amounts of ammonium and inorganic N,but at the same time reduced organic and total N leaching loss amounts.When pig manure compost was applied together with compound fertilizer,PP and total P (TP) leaching losses were reduced, but when peanut cake was applied with compound fertilizer,the leaching losses of PP and TP were elevated. Dissolved P (DP) leaching was reduced in all the combined fertilization treatments.Significant interaction effects of combined fertilization were found on leaching losses of N and P in latosolic red soils.