不同农业废弃物还田对玉米氮素吸收利用及氮平衡的影响

为研究秸秆、牛粪和鸡粪不同还田量对玉米氮素吸收积累、氮素利用率及氮平衡的影响。通过探讨不同农业废弃物还田对土壤-玉米系统的氮素表观平衡，为农业废弃物与化肥合理配施，提高氮素吸收利用效率、减少氮素损失提供理论依据和技术支撑。在等养分量(N240kg/hm²，P2O5154kg/hm²，K2O197kg/hm²)的条件下，进行田间小区试验。研究结果表明：适量的秸秆、牛粪和鸡粪还田与单施化肥相比均可显著提高玉米籽粒、茎叶和植株的氮素吸收积累量，其中25%鸡粪有机氮还田配施75%化肥氮（S10处理）玉米籽粒、茎叶和植株的氮素吸收积累量最高，分别为129.4、98.4、227.8kg/hm²。农业废弃物与化肥配施能有效降低氮素表观损失，其中S10处理氮素表观损失最低为37.7kg/hm²。适宜的秸秆、牛粪和鸡粪还田量能明显的提高氮肥表观利用率，在秸秆还田处理中，75%秸秆粉碎还田配施化肥N191.2kg/hm²(S4)氮肥表观利用率最高为44.7%比单施化肥(S1)高4.3%；在牛粪还田处理中，25%牛粪有机氮还田配施75%化肥氮(S6)的氮肥表观利用率最高为51.2%，比单施化肥处理高10.8%；在鸡粪还田处理中，25%鸡粪有机氮还田配施75%化肥氮(S10)的氮肥表观利用率最高达56.84%。比单施化肥处理高16.5%。因此，综合玉米的氮素吸收量、氮素损失量以及氮素利用率等因素，最佳还田方式为25%鸡粪有机氮还田配施75%化肥氮(S10)。

Effect of Different Agricultural Wastes Returning to Field on the Absorption and Utilization of Nitrogen and Nitrogen Balance of Maize

In order to offer theoretical foundation and technical support for the reasonably combined application of agricultural wastes and chemical fertilizer and increase nitrogen use efficiency, the author studied the influence of different returning amounts of straw, cow dung and chicken manure on the accumulation of nitrogen absorption, nitrogen use efficiency and nitrogen balance of maize, discussed the apparent balance of different agricultural wastes on soil-maize system. Field plot experiments were conducted under same level of nutrient (N 240 kg/hm², P2O5 154 kg/hm² and K2O 197 kg/hm²). The results showed that, compared with the application of chemical fertilizer only, the returning of moderate straw, cow dung and chicken manure could significant increase the accumulation of nitrogen absorption of kernel, stem leaf and plant of maize, and 25% retuning amount of chicken manure N + 75% chemical fertilizer N (treatment S10) could achieve the highest accumulation, which was 129.4, 98.4 and 227.8 kg/hm² respectively for kernel, stem leaf and plant of maize. Agricultural wastes combined chemical fertilizer could reduce apparent loss amount of nitrogen, treatment S10 had the lowest loss amount of 37.7 kg/hm². The returning of moderate straw, cow dung and chicken manure could also increase nitrogen apparent efficiency. 75% straw returning + chemical fertilizer N 191.2 kg/hm² (treatment S4) had the highest nitrogen apparent efficiency of 44.7% among straw retuning treatments, which was 4.3% higher than that of treatment S1. Among cow dung retuning treatments, the nitrogen apparent efficiency of 25% cow dung returning + 75% chemical fertilizer N (treatment S6) was 51.2%, which was 10.8% higher than that of treatment S1. Among chicken manure retuning treatments, the nitrogen apparent efficiency of 25% chicken manure returning + 75% chemical fertilizer N (treatment S10) was 56.84%, which was 16.5% higher than that of treatment S1. Therefore, integrated the absorption amount, loss amount and use efficiency of nitrogen, the optimum retuning way was 25% chicken manure N+ 75% chemical fertilizer N.