施用包膜尿素对水稻生长和氮磷流失的影响

施用新型肥料是减少养分径流损失的重要途径。采用田间试验研究了施用包膜尿素对水稻生长和径流氮磷损失的影响,试验设置CK(习惯施肥)、PU1(减磷41%、减氮20%、施普通尿素)、PU2(PU1基础上减氮13%)、UR1(PU2基础上施包膜尿素)和UR2(UR1基础上减氮13%)5个处理。结果表明:PU1和UR1处理水稻氮磷含量与CK处理相近,PU1成熟期氮、磷总积累量比CK增加11.21,2.69kg/hm~2。PU1和UR1处理成熟期地上部生物量和籽粒产量高于CK处理,籽粒产量分别提高7.68%,5.77%。PU1、PU2、UR1和UR2处理径流总磷含量和累积流失量比CK处理低,减少13.18%~21.51%。施用包膜尿素(PU1、PU2)处理径流总氮、铵氮和硝氮含量低于施用普通尿素(CK、UR1、UR2)处理;稻田径流总氮、铵氮和硝氮累积流失量分别减少12.90%~26.91%,54.52%~49.38%和4.03%~15.95%,其中包膜尿素处理铵氮累积流失量显著(P0.05)小于普通尿素处理。施用包膜尿素和优化施肥能促进水稻对氮磷养分的吸收,提高水稻籽粒产量,显著减少稻田氮磷流失量,值得在水稻生产中推广应用。

Effects of Coated Urea Application on Rice Growth and Runoff Losses of Nitrogen and Phosphorus from Paddy Field

The application of new type fertilizer is of great importance to reduce nutrient runoff losses. A field experiment was conducted to investigate the effects of coated urea application on rice growth and runoff losses of nitrogen and phosphorus from paddy field. The experiment included five treatments such as CK (conventional fertilization), PU1 (59% P, 80% N with conventional urea), PU2 (59% P, 67% N with conventional urea), UR1 (59% P, 67% N with coated urea) and UR2 (59% P, 54% N with coated urea). Results showed that nitrogen and phosphorus contents in rice of PU1 and UR1 treatments were similar to CK, but the total nitrogen and phosphorus uptake of PU1 increased by 11.21 kg/hm² and 2.69 kg/hm², respectively with the comparison to CK. The shoot dry weight and grain yield of rice of PU1 and UR1 were higher than CK, as grain yield increased by 7.68% and 5.77%, respectively. Moreover, the content and the discharge of total phosphorus through runoff from paddy field of PU1, PU2, UR1 and UR2 treatments were lower than CK, which decreased by 13.18%~21.51%. The total nitrogen (TN), ammonium-N (NH₄⁺-N) and nitrate-N (NO₃^--N) concentrations in runoff of the treatments with coated urea (PU1, PU2) were lower than that with normal urea (CK, UR1, UR2), and TN, NH₄⁺-N and NO₃^--N cumulative losses decreased by 12.90%~26.91%, 54.52%~49.38% and 4.03%~15.95%, respectively, while the NH₄⁺-N cumulative losses of the treatments with normal urea were significant lower than that with coated urea (P<0.05). The application of coated urea and optimized fertilization can promote the uptake of nitrogen and phosphorus by rice, increase rice grain yield, significantly reduce the runoff losses of nitrogen and phosphorus in paddy field, which is worthy of application in rice production.