东北典型稻区不同种植模式下稻田氮素径流损失特征研究

为了降低东北稻区稻田氮素径流损失,选择东北典型水稻种植区盘锦市,开展了不同栽培模式下水稻生长季田间氮素径流监测试验,试验设5个处理:对照(CK)、常规模式(TR)、稻蟹共生(CR)、有机水稻(OR)和减量施肥(RR),利用集水池收集各处理的地表径流,并测定径流的硝态氮、铵态氮、总氮含量,计算氮素流失量。研究结果显示:稻田地表径流损失的铵态氮远高于硝态氮;稻蟹共生和常规模式处理田间排水铵态氮的损失量相差不大,减量施肥处理比常规模式处理低26%,有机水稻处理比常规模式低73%。稻蟹共生处理比常规模式处理排水中硝态氮的排放量少23%,减量施肥处理比常规模式处理减少34%,有机水稻处理比常规模式处理低67%。稻蟹共生和常规模式处理排水总氮排放量无显著差异,分别为6.15 kg.hm 2和5.89 kg.hm 2;减量施肥处理显著低于常规模式处理,总氮排放量为4.76 kg.hm 2,比常规模式处理低19%;有机水稻处理在各水稻模式中总氮排放量最低,仅为1.93 kg.hm 2,并且显著低于常规模式处理,比常规模式处理低67%。

Nitrogen loss characteristics via runoff in typical rice planting areain Northeast China under different planting managements

A field experiment was carried out during 2011 rice growing season to investigate the effect of fertilizer management on reducing nitrogen loss via surface runoff in a typical rice system in Northeast China. The field experiment in Panjin City included five treatments: control (CK), traditional management (TR), rice-crab symbiotic management (CR), organic rice management (OR), and reducing fertilizer management (RR). The amount of nitrogen loss was determined from collected surface runoff (using collection tank) for nitrate nitrogen, ammonium nitrogen and total nitrogen contents under each treatment. The results showed that the amount of ammonium nitrogen loss was significantly higher than that of nitrate nitrogen in paddy fields. The amount of ammonium nitrogen loss under TR was not significantly different from that under CR. Compared with TR, however, the amount of ammonium nitrogen loss under RR and OR dropped by 26% and 73%, respectively. Compared with ammonium nitrogen lost by drainage under TR treatment, that under CR, RR or OR treatments dropped by 23%, 34% or 67%, respectively. With respect to total N content, no significant change was noted between TR (5.89 kg?hm²) and CR (6.15 kg?hm²). Also compared with the amount of total nitrogen loss under TR, that under CR (4.76 kg?hm²) dropped by 19%. OR had the least total N content (1.93 kg?hm²) among the treatments, significantly lower (67%) than that of TR.