长期秸秆还田对黑土碳氮及玉米产量变化的影响

Effect of Long-term Straw Returning Field on the Carbon and Nitrogen in Black Soil and Maize Yield

利用黑土长期定位试验,研究长期秸秆还田对黑土碳氮及玉米产量变化的影响。结果表明:与NPK处理比较,玉米秸秆还田处理没有显著促进黑土有机碳的积累。与试验初期相比,3个处理(CK、NPK和秸秆还田+NPK)土壤有机碳均同步增加,2006年与试验初比较均呈显著差异。与CK、NPK处理相比,秸秆还田+NPK处理能显著提高土壤N素的供应水平。各处理C/N比值在10.23～11.26之间。秸秆还田+NPK处理19年的玉米平均产量为8 958kg/hm2,与NPK处理基本一致,显著高于CK处理,表明施用有机氮(玉米秸秆还田)代替部分无机氮可以达到相同玉米产量水平。

Through long-term located experiment, the effect of long-term straw returning field on the carbon and nitrogen in black soil and maize yield were studied. The results showed that maize straw returning field could not promote the accumulation of organic carbon significantly, as compared with NPK treatment. But soil organic carbon increased a lot in three treatments, recent years of soil organic carbon compared with the initial one showed the significant difference. S＋NPK treatment could improve the supplying level of soil N, compared to the treatments CK and NPK. The ratio of C and N ranged from 10.23 to 11.26. Maize average yield in 19 years was 8 958 kg/ha with S＋NPK treatment, similarly to NPK treatment, significantly higher to CK treatment, which indicated that applying organic N （maize straw） take the place of parts of mineral N can reach the same level of maize yield completely.