稻草及其循环利用后的有机废弃物还田效用研究

Utilities of Straw and Wastes of Straw Recycling Returning on Rice Planting

【目的】研究稻草及其循环利用后的有机废弃物还田对稻田土壤肥力、生态及经济效益的影响,为稻草等有机废弃物资源化再利用提供理论依据。【方法】以无肥(O)和纯施化肥(CK)为对照,设置稻草、菌渣、牛粪、沼渣与减量化肥配施处理(NPK+S、NPK+FD、NPK+CD和NPK+BD),研究4种有机废弃物还田对土壤理化性质、CH4和N2O排放、水稻产量及经济效益的影响。【结果】4种有机废弃物还田均可一定程度地降低土壤容重、增加孔隙度及提高土壤团聚体的稳定性,提高土壤有机质、速效养分的含量,从而提高了土壤肥力水平;有机废弃物与减量化肥配施处理与CK处理相比,早稻略有减产,晚稻略有增产且实际收入也有所增加,但差异均不显著,而产投比却明显高于CK处理;有机废弃物还田处理能不同程度地增大稻田CH4排放,其中NPK+S处理增幅最大,NPK+FD、NPK+BD处理较小,但均能显著降低N2O的排放;有机废弃物还田可以减少10%—20%氮、磷、钾化肥用量,同时处理有机废弃物6250—22500kg·hm-2,节约能源的同时又减小了环境污染威胁。【结论】兼顾生产、经济、生态环境等效益,建议在南方双季稻种植区采用稻草循环利用后的菌渣、沼渣与化肥减量配施还田。

【Objective】 In order to provide a scientific basis for reusing of straw and organic wastes of straw recycling,an experiment was carried out to study the effects of straw and organic wastes of straw recycling returning on soil fertility,ecologic benefits and economic benefits.【Method】 Two control treatments with no fertilizers and sole chemical fertilizers and four organic matters treatments（straw,fungus dregs,cattle dung and biogas dregs） were designed to determine the effects of above four organic residues on soil physical and chemical characteristics,CH4 and N2O emission,rice yield,and economic benefits.【Result】 The results showed that the soil bulk density was decreased and soil porosity and stability of soil aggregate were increased in the four organic waste residues application treatmeats.The content of soil organic matter and available nutrients were also increased in the four organic waste residues application treatments.Therefore,soil fertility was improved after the four organic waste residues applied.Compared with the yield in CK treatment,the yield in treatments with the incorporation of organic waste residues had a decrease in early rice and an increase in late rice,but the differences were not significant.However,the ratio of output and input was significantly increased with organic waste residues application.Organic waste residues incorporation increased CH4 emission and decreased N2O emission significantly.The CH4 emission increased in NPK＋S treatment was the most and NPK＋FD,NPK＋BD were less.With the incorporation of organic residue（6 250-22 500 kg·hm-2）,the amount of chemical fertilizer applied was reduced by 10%-20%.Such practice not only conserves the energy but also reduces the environmental pollution potential threat.【Conclusion】 Considering the production,economic and ecological benefits,it was suggested that the incorporation of fungus dregs and biogas dregs with reduced chemical fertilizer should be adopted in the double crop rice area of south China.