红壤双季稻田不同施肥下的氨挥发损失及其影响因素

Ammonia volatilization and its influence factors under different fertilization in red paddy soil with double rice cropping system

在红壤双季稻田上采用密闭气室法测定了施用等氮量化肥(尿素)、有机肥(猪粪)及化肥有机肥(有机氮无机氮各占一半)配施下氨挥发及其田间表面水NH4+-N含量、温度和pH动态变化,研究氨挥发损失及影响因素。结果表明,与施用尿素相比,单施有机肥及化肥有机肥配施显著降低了稻田氨挥发,施用尿素的早稻和晚稻氨挥发损失率分别达41.4%和39.9%,单施有机肥的分别为0.3%和0.9%,化肥有机肥配施的分别为19.6%和8.9%。施肥后,短期内田面水NH4+-N含量和pH均显著上升,其与氨挥发速率均呈显著正相关。

Ammonia volatilization using a closed chamber method from paddy field soil and the dynamic of NH4^＋-N concentration, temperature, and pH in surface water were conducted in double rice cropping system. The effects of different types of nitrogen fertilizers applied as urea, swine manure and half of urea with swine manure in the basis of equal nitrogen on ammonia volatilization were studied. The results showed that applied swine manure and urea combing with swine manure reduced ammonia volatilization from paddy field soil significant comparing with applied chemical fertilizer urea. The N losses via ammonia volatilization account for 41.4% of total N input during early rice growth period and for 39.9% during late rice growth period by urea applied only, while the N losses via ammonia volatilization account for 0.3% during early rice growth period and 0.9% during late rice growth period for the treatment of swine manure. For the treatment of urea with swine manure, it was found that the N losses via ammonia volatilization were 19.6% during early rice growth period and 8.9% during late rice growth period, respectively. The concentration of NH4^＋-N and pH in surface water increased shortly after fertilization. Also, the positive correlation between ammonia volatilization rate with NH4^＋-N concentration and pH in surface water were obtained.