南方丘陵区旱地减磷对玉米产量及磷径流损失的影响

为探明南方旱地土壤磷素盈余问题，以湖南省浏阳市河潮土为研究对象，通过田间小区试验，探讨玉米减磷施肥对作物产量、磷肥利用率和磷流失量的影响。结果表明，与常规施磷相比，过磷酸钙减少20%范围内对玉米产量没有显著影响，减磷达到30%时玉米减产，但差异不显著；减磷施肥，磷素利用率提高1.61~4.61个百分点，同时磷径流损失量减少13.7%~22.1%；在保证产量的前提下，各减量施肥处理中，以减磷20%处理最佳。研究结果可为该地区旱地作物合理施磷和区域面源污染防控及水环境保护提供依据。

Effects of Reduced Phosphorus on Maize Yield and P Surface Runoff in Embankment Upland

To explore excess P in the em bankm entupland ofthe south C hina,the alluvialsoilin Liuyang ofH unan province w as used fora field experim entto discuss the effectofreducing P fertilization on m aize yield,the utilization ratio ofP fertilizerand the runoffloss ofP.The results show ed that P fertilizer fluctuating w ithin 20% of the conventional w ould not influence m aize yield significantly, w hen fertilizer reduced to 30% ,the yield ofm aize reduced,how everthe difference w asnotsignificant.To som e extent,the reduction ofP fertilizercould not only im prove P fertilizer utilization by 0.13% ~3.89% ,butalso low ered the runoff loss of P by 13.7% ~22.1% .Taking yield and fertilizer effects in consideration,reduced 20% P fertilizerapplication had the bestperform ance am ong allthe treatm ents.The results provided useful referencesforreasonable P fertilization,prevention ofregionalagriculturalnon-pointsource pollution and protection ofw aterenvironm ent.