秸秆配施氮磷钾肥对麦玉复种农田土壤养分的影响

Effects of Straw Combined with Nitrogen,Phosphorus and Potassium Fertilizer on Soil Nutrients in Wheat-maize Multiple Cropping Farmland

为探究秸秆还田与氮磷钾肥配施对土壤速效养分和土壤有机碳的影响,以关中地区麦玉复种旱作农田为研究对象,于2020至2021年2个连续生长季,在小麦季共设计5个处理: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进行试验。结果表明:与对照相比,秸秆还田显著增加了小麦和玉米成熟期土壤速效磷含量82.1%和27.8%,同时也显著提高了小麦成熟期土壤有机碳含量。与单施秸秆相比,秸秆配施氮磷肥在小麦和玉米成熟期速效磷含量分别增加了53.4%和38.4%,但土壤有机碳含量有降低趋势。因此,在麦玉复种期,秸秆还田与磷肥配施有助于速效磷在土壤中固持,在玉米季可适当少施,但氮、钾肥要适当补充。同时,秸秆还田有助于当季土壤有机碳提高,但对下一季土壤有机碳没有明显影响,秸秆与氮、氮磷、氮磷钾肥配施三者间土壤有机碳含量无显著差异。

In order to explore the effects of straw returning and combined application of nitrogen,phosphorus and potassium fertilizer on soil available nutrients and soil organic carbon,the wheat-maize multiple cropping dry farmland in Guanzhong area was token as the research object in two consecutive growing seasons from 2020 to 2021,and five treatments were designed in the wheat season,including single application of straw,straw combined with nitrogen fertilizer,straw combined with nitrogen and phosphorus fertilizer,straw combined with nitrogen,phosphorus and potassium fertilizer,no straw and chemical fertilizer as the control.The results showed that compared with the control,straw returning significantly increased soil available phosphorus content by 82.1%and 27.8%at wheat and maize maturity stages,and also significantly increased soil organic carbon content at wheat maturity stage.Compared with the single application of straw,the content of available phosphorus in wheat and maize increased by 53.4%and 38.4%,respectively,but the soil organic carbon decreased.During the wheat-maize multiple cropping period,straw returning combined with phosphate fertilizer could help the fixation of available phosphorus in the soil and it could be appropriately reduced in the maize season but nitrogen and potassium fertilizers should be properly supplemented.At the same time,straw returning helped to increase soil organic carbon in the current season,but had no significant effect on soil organic carbon in the next season.There was no significant difference in soil organic carbon between straw and nitrogen,nitrogen and phosphorus,and nitrogen,phosphorus and potassium fertilizers.