缓释尿素(SCU)对超级杂交中稻产量及土水中氮素的影响研究

Effect of Sulfur-coated Urea(SCU)on Yield of Super Hybrid Rice(Y Liangyou1)and Water N Content in Soil Water

为探讨超级杂交中稻超高产栽培的缓释尿素(硫包衣尿素,SCU)最佳施用量及其环境效应,在大田试验条件下,研究了SCU不同用量对超级杂交中稻Y两优1号产量以及对土水中氮素含量的影响。结果表明,与普通尿素相比,施用SCU有显著的增产效果,同等施氮量(180 kg N.hm-2)的SCU和普通尿素相比,增产幅度为13.2%;施用135 kg N.hm-2的SCU与180 kg N.hm-2普通尿素相比(氮素用量减少25%)仍可增产12.9%。稻田施氮量可显著影响土壤中铵态氮的累积和分布,但对硝态氮的影响较小。折合等量纯氮的SCU与普通尿素处理相比,可以显著减少肥料施用初期土壤水中氮素含量,施肥后10 d,SCU处理农田面水、0～20 cm层和20～40 cm层土壤水全氮含量分别为施用普通尿素处理的26.3%、64.4%和64.0%。

The field experiment was conducted at Taoyuan Experimental Station of Agriculture Ecosystem-Chinese Ecosystem Research Net-work to find out an appropriate dosage of SCU for obtaining high yield of super hybrid rice（Y Liangyou1）as well as decreasing the environ-mental risk.The results showed that：Compared with the same amount of conventional nitrogen,SCU could bring 13.2% of rice yield increase.And compared to 180 kg N.hm-2 conventional nitrogen,application of SCU 135 kg N.hm-（2N consumption decreased by 25%）could still in-crease rice yield by 12.9%.In view of the rice yield and its components,the SCU dosage of 135 kg N.hm-2 was the most applicable amount for super-hybrid rice Y Liangyou 1.In paddy field,the quantity of N fertilizer application could significantly affect the amount of ammonium ni-trogen accumulation and distribution in soil water,but nitrate was less affected.Compared with urea in equivalent net nitrogen,SCU could significantly reduce the nitrogen content in soil water shortly after the application of N fertilizer.10 days after fertilization,the percentage of total N content in the treatment of SCU against urea was 26.3%,64.4% and 64.0%,repectively,in surface water,0~20 cm and 20~40 cm layer of soil water.SCU fertilizer can effectively reduce the risk of water pollution shortly after the usage of N fertilization.