规模化猪场处理废水与化肥配施对小麦氮素吸收利用的影响

规模化猪场处理废水富含植物营养物质,应用于作物生产可实现减少化肥用量和保护环境的双赢。本研究通过田间试验,研究了越冬期不同用量养猪处理废水(30、60、90 m3·hm-2和120 m3·hm-2)和穗期施氮水平(0、30、60 m3·hm-2和90 m3·hm-2)对小麦氮素吸收利用的影响。结果表明,猪场处理废水对小麦具有较好的氮素养分供应作用,拔节期、抽穗期、成熟期叶片SPAD值、植株含氮率都随着污水施用量增加而提高。废水施用60 m3·hm-2以上穗期配施氮90 kg·hm-2的处理花后氮素转移效率、氮素收获指数、氮素籽粒生产效率明显下降。越冬期施用养猪场处理废水60～120 m3·hm-2替代穗期施氮30～60 kg·hm-2,可以满足不同时期小麦氮素营养的需求,并且有较高的氮素积累量和利用效率。

Nitrogen Uptake and Utilization in Wheat as Influenced by Pig Slurry from Large-scale Pig Farm

Pig slurry contains rich plant nutrients and can be applied in crop production, thus reducing uses of chemical fertilizers and protecting the environment. A field experiment was conducted in Dafeng, Jiangsu Province, to evaluate the effects of pig slurry applications combined with chemical fertilizer on nitrogen uptake and use efficiency in wheat. Zhengmai9023, a widely cultivated wheat variety in the south of Huaihe River, was employed. The pig slurry used in the experiment contained 1000 mg·L-1 of total nitrogen, 540 mg·L-1 of available nitrogen and 779 mg·L-1 of extractable phosphorus. The concentration of Cu, Zn, Pb, Cd, Cr, As, and Hg in the pig slurry was 0.246 mg·L-1, 0.577 mg·L-1, 0.041 mg·L-1, <5.0×10-4 mg·L-1, 0.063 mg·L-1, 0.028 3 mg·L-1, and <5×10-4 mg·L-1, respectively, conforming to standards for irrigation water quality. The leaf SPAD values, nitrogen contents, and nitrogen accumulation in wheat plants at jointing, heading and maturing stages were increased with rates of pig slurry. Applying pig slurry at 60~120 m3·hm-2 during overwintering period instead of applying 30~60 kg N·hm-2 of chemical fertilizer at panicle formation stage could meet nitrogen nutrition demand of wheat with higher nitrogen accumulation and utilization efficiency. However, application of pig slurry over 60 m3·hm-2 followed by 90 kg·hm-2 chemical fertilizer at panicle formation stage significantly reduced nitrogen use efficiency.