施肥对黄土旱塬区黑垆土土壤肥力及硝态氮累积的影响

Effect of fertilization on fertility and nitrate accumulation of black loessial soil of dry land in Loess Plateau

本文以长期定位试验为依托,研究了黄土高原旱塬区黑垆土大田对比试验和长期定位施肥对土壤肥力及硝态氮累积和淋溶的影响。结果表明:长期施用有机肥能够明显增加土壤养分,氮磷和有机肥配施效果显著;和1984年土壤养分状况相比,大田对比试验土壤有机质增加了27.1%,全氮和全磷提高了84.2%和34.8%,有效氮、有效磷和速效钾增加了46.9%、540.0%和10.2%,养分水平与长期定位试验中氮磷配施相近。长期定位试验中氮磷配施或与有机肥配施能够有效地减少土壤剖面中硝酸盐的累积和淋溶,氮肥单施硝态氮累积量最大,为1006.4kg/hm2,大田对比试验土壤硝态氮总累积量较长期定位试验中施用氮肥处理的总累积量少。

Based on a 22 years long-term experiment of applying fertilizers on continuous wheat, the effect of fertilization on soil fertility and nitrate accumulation of black loessial soil of dry land in Loess Plateau was studied. The results showed that long-term application of manure（M） and combination applying of NPM could significantly increase soil fertility. Compared to the soil nutrient content in 1984, the farmland under current fertilization increased the contents of soil organic matter, total N, total P available N, available P and available K by 27.1% , 84.2%, 34.8% , 46.9% , 540.0% and 10.2 %, respectively. The soil fertility status was similar to the soil under NP treatment in the long-term experiment. Combination applying NP or NPM could reduce nitrate accumulation and leaching. The highest nitrate accumulation （1006.4 kg/ha） was found under the treatment of solo N application. Soil nitrate accumulation in field was lower than that under long-term experiment.