秸秆配伍腐秆剂还田的最适氮肥运筹方案研究

Study on the optimal amount of nitrogen fertilizer under straw returning with decomposing microorganism inoculum

为明确沿淮地区秸秆配伍腐秆剂还田条件下氮肥的最佳施用方案,提升该区秸秆还田替代化学肥料的效率。利用布设于安徽霍邱的麦秸配施腐秆剂还田试验,比较了不同氮肥运筹处理:(1)麦秸还田+腐秆剂(CN_(105),C/N=105∶1);(2)麦秸还田+腐秆剂+减基增穗施N肥(CN_(24),C/N=24∶1);(3)麦秸还田+腐秆剂+推荐方案施N肥(CN_(18),C/N=18∶1);(4)麦秸还田+腐秆剂+增基减穗施N肥(CN_(12),C/N=12∶1),在秸秆腐解和水稻生产等方面的差异。研究结果表明:不同氮基肥用量会显著影响腐秆剂的促腐速率,C/N为18∶1时还田秸秆的腐解速率最大(k=0.023),较CN12和CN24处理可分别提高43.75%和35.29%;CN_(18)处理的水稻产量与CN_(105)、CN_(24)和CN_(12)处理相比有不同程度的增加,增幅分别为13.64%、0.09%和13.09%(P>0.05);秸秆腐解率与水稻产量和水稻千粒重呈正相关,而与水稻的有效穗数、穗粒数和结实率呈负相关,其中与产量的相关性显著(P<0.05)。由上可知,沿淮地区麦秸配施腐秆剂还稻田时配施氮基肥使初始C/N为18∶1可显著加速秸秆腐解,并有增产的趋势。

To explore the optimal amount of nitrogen fertilizer under straw returning with decomposing microorganism inoculum in the area along Huaihe River.We compared the decomposition rate of the straw returned to the field and the yield and its component of rice among following four treatments:(1)straw returning with decomposing microorganism inoculum(initial C/N=105∶1,CN_(105));(2)straw returning with decomposing microorganism inoculum and fertilized conventional N base fertilizer(C/N=24:1,CN_(24));(3)straw returning with decomposing microorganism inoculum and fertilized less N base fertilizer(C/N_(18):1,CN18);(4)straw returning with decomposing microorganism inoculum and fertilized more N base fertilizer(C/N=12∶1,CN_(12)).The results showed that:the amount of different nitrogen base fertilizer can significantly affect the decay promoting rate of culm.The decomposition rate of returning straw was the highest(k=0.023)when C/N was 18∶1,which was 43.75%and 35.29%higher than that of C/N was 12 and 24,respectively.Compared with CN_(105),CN_(24)and CN_(12),the rice yield under CN18 treatment increased by 13.64%,0.09%and 13.09%,respectively(P>0.05).The decomposition rate of the straw returned to the field was significantly positively correlated to yield and 1000-grain weight of rice,and it had a negative correlation with effective panicle,panicle grain number as well as seed setting rate.Quite obvious,adjusting the initial C/N to 18 should be recommended when straw returning with decomposing microorganism inoculum in the area along Huaihe river.That can promote not only straw rot but also increase cropyield.