猪粪施用对成都平原稻季氨挥发特征的影响

Effects of Pig Manure Applications on Ammonia Volatilization in Soil During Rice Season in Chengdu Plain

采用通气法开展田间小区原位监测试验,分别设置对照、常规化肥、猪粪和化肥配施、单施猪粪等7个处理,探讨不同比例猪粪施用对稻田氨挥发特征及环境、效益的影响。结果表明,氨挥发通量在施肥后的第2 d达到峰值,然后迅速下降,氨挥发主要集中在施肥后的1周左右。在整个监测期间,氨挥发平均通量为2.87~5.89 kg·hm-2·d-1,氨挥发累积量为43.72~87.38 kg·hm-2,占氮肥施用量的24.27%~29.17%;猪粪和化肥配施处理较常规施肥处理能降低氨挥发累积量4.21%~16.74%,猪粪和化肥配施也有效降低了田面水铵态氮和硝态氮浓度,单施过量猪粪则促进了氨挥发;氨挥发通量与田面水铵态氮浓度呈明显线性正相关。猪粪和化肥配施处理较常规施肥处理稻谷增产196~779 kg·hm-2,同时猪粪的施用也降低了稻田肥料投入成本,有效提高了农民纯收入。综合环境及经济效益,化肥+猪粪50%处理的猪粪投入量最佳,稻田猪粪消纳量为13 264.54 kg·hm-2,生猪承载量为20.19头·hm-2。

A filed plot experiment was conducted to examine the ammonia volatilization in paddy field supplied with pig manure during rice season. Ammonia volatilization mainly occurred within one week or so after fertilization. The fluxes of ammonia volatilization peaked on the second day after fertilization, and then decreased rapidly. During the monitoring period, the average flux of ammonia volatilization was 2.87~5.89 kg·hm-2·d-1, and the cumulative amount of ammonia volatilization was 43.72~87.38 kg·hm-2, accounting for 24.27%~29.17% of total amount of nitrogen fertilizer. Compared with the conventional fertilization, applications of pig manure with conventional fertilizers reduced cumulative amount of ammonia volatilization by 4.21%~16.74%, whereas applying pig manure alone would promote ammonia volatilization.The combined applications of pig manure and chemical fertilizer reduced ammonium nitrogen and nitrate in the water. The flux of ammonia volatilization showed a significant linear positive correlation with ammonium nitrogen concentration in the surface water. In the treatments with combined pig manure and chemical fertilizer, the rice grain yields increased by 196~779 kg·hm-2, as compared with chemical fertilizer alone. Moreover, the applications of pig manure decreased the inputs of chemical fertilizers and thus increased farmers′ net income.Taking into consideration of the environmental and economic benefits, chemical fertilizer plus 50% manure would be the optimal application amount, which could consume swine manure up to 13 264.54 kg·hm-2and carry pigs up to 20.19 pigs·hm-2.