施用控释氮肥对减少稻田氮素径流损失和提高水稻氮素利用率的影响

采用渗漏池模拟研究了洞庭湖区双季稻种植条件下施用控释肥料对氮素径流损失、水稻产量和稻株氮素含量的影响。结果表明，施用等N量控释氮肥 (CRNF) 和70%N量控释氮肥 (70% CRNF) 的处理总氮 (TN) 径流损失量比施用尿素处理 (CF) 分别降低了24.5%和27.2% (P0.05)。主要是施用控释氮肥显著降低了水稻前期 (施肥后10 d内)的径流水中氮素浓度。与施用尿素相比，两种土壤上施用控释肥的早、晚稻产量均明显提高，特别是在河沙泥上，稻谷总产量以70% CRNF处理最高，比尿素处理增产4.95% (P0.05)。控释氮肥能明显提高水稻生长后期的植株和子粒中的N含量；在水稻增产显著的河沙泥上，70% CRNF处理的早、晚稻子粒N含量较CF处理提高了9.4% (P0.05)和23.3%(P0.01)；其氮素利用率高于施用全量尿素的CF处理。

Effect of controlled-release nitrogen fertilizer on reducing nitrogen runoff loss and increasing nitrogen recovery efficiency of rice plant

The effects of controlled-release nitrogen fertilizer (CRNF) on nitrogen runoff loss, rice yield and nitrogen content in rice plant were studied under double rice cropping system in paddy soil of Dongting Lake Area using lysimeter simulation. The results showed that the amount of total nitrogen (TN) losses due to runoff in CRNF treatment and 70% CRNF treatment was reduced by 24.5% and 27.2% (P<0.05) compared with urea treatment, because of great decrease of nitrogen concentrations in runoff water with CRNF application during the early growth stages of rice (within 10d after application). The total yields of early and late rice in two types of paddy soils were increased significantly in both controlled-release nitrogen fertilizer treatments than in urea treatment, especially in alluvial sandy loamy paddy soil, which was increased by 4.95%(P<0.01) in the 70% CRNF treatment compared with the urea treatment. Applying CRNF could also increase N contents in rice plant and grain during late growth stage of rice compared with using urea. In Alluvial sandy loamy paddy soil, N contents in rice grain of early and late rice were increased by 9.4%(P<0.05) and 23.3%(P<0.01) in the 70% CRNF treatment as compared with the urea treatment. The nitrogen utilization efficiency was higher in the 70% CRNF treatment than in the urea treatment, especially in the alluvial sandy loamy paddy soil.