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通过田间小区和渗滤桶试验相结合的方法,研究树脂包膜尿素(释放期为30d的PCU30和释放期为60d的PCU60),硫包衣尿素(SCU),抑制剂缓释尿素(UI)和普通尿素(U)对高羊茅草坪生长、氮素吸收及硝态氮土壤残留与淋失的影响。结果表明,与U处理相比,在全年施氮量260kg/hm2的情况下,4种缓控释氮肥均可显著提高草屑累积量和肥料利用率。其中PCU60和SCU处理肥料利用率分别为22.51%和23.07%,显著高于其他处理。PCU30、PCU60和SCU 3种包膜型缓控释肥料土壤中硝态氮残留高于其他施氮处理(P<0.05)。试验中各处理的硝态氮淋溶量水平较低,在1.2~3.99kg/hm2之间,损失从高到低依次为:U>UI>SCU>PCU30>PCU60,其中U处理的硝态氮累积淋溶量显著高于其他处理。综合试验结果,北京地区高羊茅草坪一年分春秋2次施用PCU60可满足草坪正常生长需要,降低氮素淋溶损失,提高肥料利用率,适于推广应用。
The effects of resin-coated urea (PCU30 with 30 days of release and PCU60 with 60 days of release), sulfur-coated urea (SCU) and inhibitor of sustained-release urea (UI) And Urea (U) on growth, nitrogen uptake and nitrate residue of lettuce fescue in turfgrass were studied. The results showed that compared with U treatment, all the four controlled-release nitrogen fertilizers could significantly increase the grass culm accumulation and fertilizer use efficiency under the condition of annual nitrogen application rate of 260 kg / hm2. The PCU60 and SCU fertilizers utilization rates were 22.51% and 23.07%, respectively, significantly higher than other treatments. The residual nitrate nitrogen in the three controlled release fertilizers (PCU30, PCU60 and SCU) was higher than that of other N treatments (P <0.05). In the experiment, the leaching amount of nitrate nitrogen in each treatment was relatively low, ranging from 1.2 to 3.99 kg / hm2, the order of loss was U> UI> SCU> PCU30> PCU60, Cumulative leaching was significantly higher than other treatments. According to the results of comprehensive test, PCU60 can be applied two times a year to the tall fescue turfgrass in Beijing to meet the requirement of normal growth of lawn, reduce the leaching loss of nitrogen and improve the utilization rate of fertilizer, which is suitable for popularization and application.