秸秆与氮磷钾肥配施对麦玉复种农田作物生产力与养分利用的影响

Effects of combined application of straw with nitrogen,phosphorus and potassium fertilizers on crop productivity and nutrient utilization in wheat-maize multiple cropping farmland

目的 为探究秸秆还田下配施氮、磷、钾肥对麦玉复种农田作物养分利用效率及产量的影响,推动秸秆还田下高效施肥策略。方法 该试验于2020至2021年两个连续生长季,以关中地区麦玉复种旱作农田为研究对象,在小麦季共设计5个处理:即单施秸秆、秸秆配施氮肥、秸秆配施氮磷肥、秸秆配施氮磷钾肥、以不施秸秆和化肥为对照。探究秸秆还田与氮磷钾肥配施对冬小麦和夏玉米地上部植株生物量、氮磷钾积累量、氮肥利用效率及产量的影响,以期为秸秆还田条件下的肥料管理提供科学依据与技术支撑。结果 冬小麦和夏玉米地上部干物质及氮磷钾积累量随氮、磷、钾肥配施种类的增加而提高。相较于不施秸秆,单施秸秆处理对当季小麦籽粒产量有降低趋势,但能增加下茬玉米籽粒产量,相较于单施秸秆,秸秆配施氮、氮磷、氮磷钾肥小麦和玉米产量分别显著增加了114.1%、128.8%、131.6%和25.4%、24.4%、23.7%.与CK、单施秸秆相比,秸秆配施化肥均显著增加了当季小麦和下季玉米的生物量、穗粒数、籽粒产量。与秸秆配施氮肥相比,秸秆配施氮磷、氮磷钾肥对小麦籽粒氮肥利用效率、氮肥偏生产力、氮肥农学效率有增加趋势,但未达到显著性差异,对玉米季无明显影响。结论 通过该试验发现秸秆还田下平衡施肥对小麦、玉米的氮肥利用效率、氮肥偏生产力、氮肥农学效率没有显著提高。相较于对照和单施秸秆处理,秸秆配施氮、氮磷及氮磷钾肥能显著提高小麦穗数、穗粒数、千粒重和产量,同时也能显著提高玉米穗粒数和产量。在实际农业生产中,秸秆还田条件下小麦季要注重平衡施肥,根据土壤初始养分情况,在玉米季氮肥用量充足的情况下,适当减施磷、钾肥,这样在保障产量的同时,也有利于降低经济成本。

Objective In order to explore the effects of combined application of nitrogen,phosphorus and potassium fertilizers on the nutrient absorption efficiency and yield of wheat-maize multiple cropping farmland,and to promote the efficient fertilization strategy of straw returning to the field.Methods The trial was carried out for two consecu-tive growing seasons from 2020 to 2021,and the wheat-maize multi-cropping dry farmland in Guanzhong area was taken as the research object.A total of five treatments were designed in the wheat season,including fertilizing straw alone,straw with nitrogen fertilizer,straw with nitrogen and phosphorus fertilizer,straw with nitrogen,phosphorus and potassium fertilizer,and no straw and chemical fertilizer as the control.Issues as effects of straw returning to the field and the combined application of nitrogen,phosphorus and potassium fertilizers on plant biomass,nitrogen,phos-phorus and potassium accumulation,nitrogen use efficiency and yield in the shoots of winter wheat and summer maize were investigated,so as to provide scientific basis and technical support for fertilizer management under the condition of straw returning to the field.Results The accumulation of dry matter and nitrogen,phosphorus and potas-sium in the shoots of winter wheat and summer maize increased with the increase of nitrogen,phosphorus and potassi-um fertilizer.Compared with no straw application,the single straw application had a decreasing trend on the grain yield of wheat in the current season,but could increase the grain yield of maize in the next season.Compared with single application of straw,straw combined with nitrogen,or nitrogen and phosphorus,or nitrogen,phosphorus and po-tassium fertilizer,the yields of wheat and maize were significantly increased by 114.1%,128.8%,131.6%and 25.4%,24.4%,23.7%,respectively.Compared with CK and single application of straw,the application of straw combined with chemical fertilizer significantly increased the biomass,grain number per spike and grain yield of wheat in the current season and maize at the next season.Compared with straw combined with nitrogen fertilizer,the combined ap-plication of nitrogen and phosphorus,or nitrogen,phosphorus and potassium fertilizer with straw had an increasing trend on the nitrogen use efficiency,partial productivity of nitrogen fertilizer,and nitrogen agronomic efficiency of wheat grains,but there was no significant difference,and there was no significant effect on maize season.Conclusion In this experiment,it was found that balanced fertilization of straw returning to the field did not signifi-cantly improve the nitrogen use efficiency,nitrogen partial productivity,and nitrogen agronomic efficiency of wheat and maize.Compared with the control and single straw treatment,straw combined with nitrogen,or nitrogen and phosphorus,or nitrogen,phosphorus and potassium fertilizers could significantly increase the number of spikes,grains per spike,1000-grain weight and yield of wheat,and also significantly increase the number of grains per spike and yield of maize.In the actual agricultural production,balanced fertilization should be paid attention in the wheat season under the condition of straw returning to the field.According to the initial situation of the soil nutrients,in the case of suffcient nitrogen fertilizer dosage in the corn season,it is necessary to appropriately reduce the application of phosphorus and potassium fertilizers so as to ensure the yield and reduce the economic cost.