灌漠土长期有机配施土壤肥力特征和作物产量可持续性分析

为揭示长期施用有机肥对灌漠土土壤培肥效果,依托甘肃河西绿洲灌区灌漠土长期定位培肥试验(1988-至今),设计有机肥磷肥配施(MP)、有机无机配施(1/2MN+P)、氮磷配施(NP)和不施肥(CK)4个处理,测定其第31年和已有的土壤养分和作物产量数据,研究灌漠土长期有机培肥对土壤肥力特征和作物产量的影响。结果表明:有机无机配合施用第31年和历年平均值与试验初始值相比,土壤有机质增加72.5%和24.9%,土壤全氮增加72.3%和25.7%,土壤全钾增加16.1%和33.0%;与无肥对照(CK)相比,土壤有机质增加54.9%和19.1%;土壤全氮增加47.3%和14.9%,土壤全磷增加73.0%和15.3%。有机无机配合施用能有效降低土壤pH。有机无机配施处理第31年和逐年平均值与对照(CK)相比,小麦/玉米间作体系产量增加149.2%和139.2%,肥料贡献率(FCR)为0.58,变异系数(CV)为0.21,可持续性指数(SYI)为0.61,养分和产量各项指标均达到高优水平。灌漠土长期有机无机配施措施能持续增加灌漠土土壤有机质、全氮、全磷、全钾、碱解氮、有效磷和速效钾含量,降低土壤pH,提高土壤肥力和肥料贡献率,显著提高小麦/玉米间作体系产量及其稳定性和可持续性。研究结果可为甘肃河西绿洲灌区农田土壤科学培肥和农业可持续发展提供决策依据。

Analysis on Soil Fertility Characteristics and Crop Yield Sustainability of Irrigated Desert Soil with Long-term Organic Fertilization Application

In order to reveal the effect of long-term organic fertilization on soil fertility of irrigated desert soil, based on the long-term fertilization experiment of irrigated desert soil in Hexi oasis irrigation area of Gansu province (1988 to present), four treatments including organic phosphate fertilizer (MP), organic and inorganic NPK (1/2 MN + P), nitrogen and phosphorus (NP) and no fertilizer (CK) were designed. Based on the existing test data of soil nutrient and crop yield and those data measured in the 31st year, the effects of long-term organic fertilization on soil fertility and crop yield in desert soil were studied. The results showed that compared with the initial value of the experiment, the average soil nutrient value of the past years and that in the 31st year of organic-inorganic combined application all increased, which indicted that the soil organic matter increased by 72.5% and 24.9%, soil total nitrogen increased by 72.3% and 25.7%, and soil total potassium increased by 16.1% and 33.0%. Compared with non-fertilizer control (CK), soil organic matter increased by 54.9% and 19.1%, soil total nitrogen increased by 47.3% and 14.9%, and soil total phosphorus increased by 73.0% and 15.3%. Combined application of organic and inorganic fertilizer could effectively reduce soil pH. Compared with CK, the average value of the past years and that in the 31st year of organic-inorganic combined application showed that the yield of wheat/maize intercropping system increased by 149.2% and 139.2%, fertilizer contribution rate (FCR) was 0.58, coefficient of variation (CV) was 0.21, and sustainability index (SYI) was 0.61. Nutrient and yield indexes all reached high quality level. In Hexi oasis irrigation area, Gansu province, long-term combined application of organic and inorganic could continuously and significantly increase the contents of soil organic matter, total nitrogen, total phosphorus, total potassium, alkali-hydrolyzed nitrogen, available phosphorus and available potassium, reduce soil pH and increase soil fertility and the contribution rate of fertilizer. It could significantly improve the yield, stability and sustainability of wheat/maize intercropping system. This study could provide decision-making basis for scientific fertilization of farmland soil and sustainable development of agriculture in Hexi Oasis Irrigation Area of Gansu Province.