长期施肥对黄土高原黄绵土区小麦产量及土壤养分的影响

Effect of Long-term Fertilization on Wheat Yield and Nutrient Content of Loessial Soil on Loess Plateau

为探明在小麦长期连作条件下,黄土高原黄绵土区长期施肥对小麦产量及土壤养分的影响,以长达29年(1981-2010)的长期定位试验为基础,比较分析了不同长期施肥处理下小麦产量及土壤养分的差异。结果表明,施用有机肥和化肥的小麦籽粒产量较不施肥对照(CK)都明显增加,25年N、NP、NPK、M、MN、MNP和MNPK处理的小麦平均产量分别较CK增产32.9%、74.1%、78.5%、42.2%、73.3%、89.5%和90.3%,而7个施肥处理的肥料平均产量贡献率分别为24.8%、42.6%、44.0%、29.7%、42.3%、47.2%和47.4%。氮、磷、钾肥的平均增产效应分别为5.8、22.9和1.6g·kg-1。连续29年施用有机肥(M)显著提高了土壤有机碳含量,而且化肥无论是单施(N),还是平衡施用(NP和NPK),土壤有机碳含量较CK也可显著提高,平衡施用的效果更佳。施用氮肥及有机肥也显著提高了土壤全氮和速效氮含量。施用磷肥和有机肥显著提高土壤全磷和速效磷含量,而长期施用钾肥和有机肥对土壤全钾含量无明显影响,但显著提高了土壤速效钾含量。

To investigate the response of wheat yield and soil nutrient related to long-term fertilization under continuous monoculture condition in loessial soil on loess plateau, the effects of long-term fertilization on wheat yield and soil nutrient content were studied on the basis of 29 years（1981--2010） experiments at Tianshui city of Gansu province. The results showed that application of both manure and chemical fertilizers could markedly increase grain yield of winter wheat, and the mean yield was enhanced by 32.9%,74.1%,78.5%,42.2%,73.3%,89.5% and 90.3%,respectively,with the N,NP, NPK,M,MN,MNP and MNPK treatments during 25 years,compared to control（CK） treatment. The contribution rates of fertilizer of 7 treatments were 24.8%,42.6%,44.0%,29.7%,42.3%,47.2% and 47.4% ,respectively. The average field efficiency was 5.8 g . kg-1 for nitrogen,22.9 g . kg-1 for phosphorus and 1.6 g . kg-1 for potassium,with and without manure treatments. Soil organic carbon content in 0-20 cm top soil was significantly increased with the consecutive inputting of organic fertilizer in 29 years. Single or balanced application of chemical fertilizers could markedly increase soil organic carbon content,compared to control（CK） treatment. Yet balanced application of chemical fertil-izers（NP and NPK） had better effects. Application of nitrogen fertilizer and organic fertilizer signifi- cantly increased soil total nitrogen and available nitrogen content, and application of phosphate fertilizer and organic fertilizer significantly improved the soil total phosphorus and available phosphorus content. However, long-term application of potassium fertilizer and organic fertilizer had no obvious effect on soil total potassium content, but significantly increased the soil available potassium content.