小麦秸秆还田对茭白土壤理化性质及产量的影响

Effect of Wheat Straw Returning to Fields on Soil Physical and Chemical Properties and Yield of Zizania latifolia

为探明小麦茭白水旱轮作模式下小麦秸秆不同还田处理方式对土壤理化性质、田面水水质变化及茭白产量品质的影响,以常规基施化肥为对照,设置秸秆全量还田+基施化肥、秸秆堆肥(秸混肥)还田+基施化肥、秸混肥还田+缓释肥替代化肥基施、常规基施化肥减量20%5个处理。结果表明,小麦秸秆不同还田方式处理对茭白采收后土壤pH、全氮含量的影响不大,秸秆全量还田处理的土壤EC值、碱解氮和速效钾含量最高。与对照相比,秸混肥还田可显著增加土壤有机质含量,并提高茭白产量,但茭白品质改善的效果不显著。秸混肥还田+缓释肥替代化肥基施处理的土壤碱解氮和速效钾含量较对照显著降低,但茭白产量最高。基施化肥减量处理土壤有效磷含量显著高于对照,对茭白产量品质无明显影响。茭白不同生长时期田面水的采样检测结果表明,各处理田面水pH、COD和总磷、全钾含量变化趋势基本一致,且硝态氮含量均低于检出限(0.5 mg·L^(-1)),小麦秸秆还田对茭白田面水面源污染无影响。综上,麦茭水旱轮作模式下小麦秸秆还田可用于培肥土壤、增加茭白产量和控制面源污染。

In order to explore the effects of different treatments of returning wheat straw to fields on soil physical and chemical properties,water quality changes in surface water,water bamboo yield and quality under water-dry rotation mode of wheat and Zizania latifolia,this study took conventional base fertilizer as the contrast and set up 5 fertilizer treatments,including base fertilizer and full straw returning to fields,base fertilizer plus straw manure(straw compost)returning to fields,straw compost returning to fields and slowrelease fertilizer replacing conventional fertilizer application,and routine chemical fertilizer application reduced by 20%.The results showed that different treatments of returning wheat straw to fields had little influence on soil pH and total nitrogen content after Z.latifolia harvest.Soil EC value,alkali-hydrolyzable nitrogen and available potassium contents after full amount of straw returning to fields were the highest.Compared with the contrast,the straw manure returning to fields could significantly increase soil organic matter content and increase Z.latifolia yield,but the quality of Z.latifolia were not significantly different.Soil contents of alkalihydrolyzable nitrogen and available potassium treated with straw compost and slow-release fertilizer replacing chemical fertilizer were significantly lower than that of the contrast,but the yield of Z.latifolia was the highest.The content of soil available phosphorus in the treatment of reduction of base fertilizer application was significantly higher than that in the contrast.And there were also no remarkable influence on yield and quality of Z.latifolia.The result of sampling and testing the surface water of Z.latifolia fields showed that at different growth stages the changing trend of pH,COD,total phosphorus and total potassium in surface water of each treatment was basically the same,and the content of nitrate nitrogen was lower than the detection limit(0.5 mg·L^(-1)).Wheat straw returning to fields had no effect on surface water pollution in Z.latifolia fields.To sum up,wheat straw returning to fields,bamboo and rice field-upland field rotation can be used for improving soil fertility,increasing yield and controlling pollution from non-point sources.