河西绿洲灌区灌漠土长期秸秆还田土壤肥力和作物产量特征分析

系统研究长期秸秆还田对河西绿洲灌区灌漠土壤养分的演变规律、土壤肥力特征的影响,分析作物产量及稳定性和持续性,为秸秆还田培肥土壤和资源化利用提供科学和理论依据.利用河西绿洲灌区31年(1988-2018年)的灌漠土长期定位培肥试验,开展了以秸秆与磷肥配施(SP)、秸秆与氮磷肥配施[1/2(S+N)P]、氮磷配施(NP)、不施肥(CK)为处理的田间定位试验,测定了耕层0～20 cm土壤有机质(SOM)、全氮(TN)、全磷(TP)、全钾(TK)、速效氮(AN)、速效磷(AP)、速效钾(AK)、pH,研究了长期秸秆还田对小麦/玉米间作体系灌漠土土壤养分演变规律和作物产量的影响.结果表明:秸秆还田第31年和逐年平均值与试验初始值相比,土壤有机质增加73.3％和25.8％,土壤全氮增加50.6％和21.7％,土壤全磷增加22.5％和3.8％,土壤全钾含量增加19.9％和38.2％;与对照(CK)相比,土壤有机质增加55.3％和20.0％;土壤全氮增加28.8％和15.9％,土壤全磷增加50.2％和13.4％;土壤全钾增加23.5％和0.2％.秸秆连续还田9年后小麦产量比对照平均降低5.8％,第10年开始小麦产量逐年增加,比对照平均增加65.9％.玉米产量在秸秆连续还田13年间比对照平均降低8.2％,之后较对照平均增加22.0％.河西绿洲灌区灌漠土长期施用秸秆或秸秆氮磷肥配施,土壤培肥效果均显著优于单施化肥,可显著增加土壤有机质含量,提升土壤肥力,秸秆与氮磷化肥配施能持续提升作物产量及其稳定性和可持续性.

Analysis of soil fertility and crop yield characteristics following long-term straw return to the field in a Hexi Oasis irrigated area

This paper reports a long-term (1988-2018) study of the effects of straw return, with and without fertilizer application, on productivity and soil nutrient status in a desert soil in the Hexi oasis irrigation area. The research was conducted to provide scientific data to inform management decisions on straw return and resource utilization. Data on soil fertility, crop yield, crop stability and sustainability were collected. Soil fertility data included total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium and pH in the 0-20 cm soil horizon. Treatments included straw return with phosphorus fertilizer, straw return with nitrogen and phosphorus fertilizers;nitrogen and phosphorus and no fertilization. The effects of long-term straw return on evolution of soil nutrient status and crop yield in a wheat-maize inter-cropping system were studied. It was found that content of the soil and crop tissues, respectively, for organic matter increased by 73.3% and 25.8%, total nitrogen increased by 50.6% and 21.7%, total phosphorus increased by 22.5% and 3.8%, and total potassium content increased by 19.9% and 38.2%, compared with the initial value at the start of the experiment. Compared with CK, soil organic matter increased by 55.3% and 20.0%, total nitrogen increased by 28.8% and 15.9%, total phosphorus increased by 50.2% and 13.4% and total potassium increased by 23.5% and 0.2%. After nine successive years of straw return, the wheat yield decreased by 5.8% on average, but increased by 65.9% from the 10th year. The yield of maize decreased by 8.2% in 13 years, and then increased by 22.0% compared with CK. Long-term application of straw or straw N and P fertilizer resulted in better soil fertility than single application of chemical fertilizer, which can significantly increase soil organic matter content and soil fertility. Combined application of straw and nitrogen and phosphorus fertilizer greatly improved crop yield, stability and sustainability. © 2021, Editorial Office of Acta Prataculturae Sinica. All rights reserved.