包膜控释氮肥配施尿素对冬小麦产量与氮素积累及利用的影响

Effects of coated controlled-release nitrogen fertilizer combined with urea on yield,nitrogen accumulation and utilization of wheat

【目的】研究包膜控释氮肥与尿素配施对冬小麦氮素积累、分配、利用率和产量的影响,为筛选控释氮肥配施尿素的适宜比例提供参考。【方法】在成都平原,2014和2015年采用冬小麦大田试验,设置不施氮处理(CK)及普通尿素与控释氮肥不同配比(0(T1),10%(T2),20%(T3),40%(T4),80%(T5),100%(T6))处理,肥料均一次性基施,研究控释氮肥不同配施比例对冬小麦产量及其构成因素、经济效益和氮素利用率的影响。【结果】两年田间试验结果表明,小麦产量均以T4处理最优,较单施尿素T1处理增产697.06kg/hm2(2014年)和521.02kg/hm2(2015年),较单施控释氮肥T6处理增产383.86kg/hm2(2014年)和400.43kg/hm2(2015年)。配施20%~40%控释氮肥处理(T3、T4)的纯收益较其余处理明显增加,较T1处理提高16.73%~23.24%(2014年)和4.05%~14.31%(2015年)。各施氮处理均能改善产量构成因子,其中以T4处理较优,且该处理成熟期旗叶、倒二叶和顶二叶面积均最大。T4处理地上部氮累积量最大(拔节期到成熟期),籽粒氮素累积量明显高于其余处理(成熟期)。随控释氮肥施用比例的增加,氮肥偏生产力、农学利用率、氮素吸收效率、表观利用率均先升高后降低,以T4处理最高,氮依存率的变化趋势与之相反,且施氮处理氮收获指数差异较小。小麦成熟期土壤不同形态氮含量均随控释氮肥施用比例的增大而上升。配施40%~100%控释氮肥的处理较T1处理的土壤硝态氮、微生物量氮、碱解氮和全氮含量显著增加。【结论】控释氮肥和尿素配施能有效改善小麦关键生育时期顶二叶的发育,协调籽粒的氮素积累与分配,提高氮素利用率,有利于保障作物高产。综合各因素,推荐采用尿素配施20%~40%控释氮肥作为成都平原冬小麦生产的适宜配比。

【Objective】Effects of combined application of coated controlled-release nitrogen fertilizer（CRNF）and urea（UR）on yield and nitrogen accumulation,distribution and use efficiency of wheat were studied to screen suitable combination of CRNF and UR in wheat production.【Method】Field experiments with CK and treatments with different CRNF ratios（T1,T2,T3,T4,T5,and T6 with 0,10%,20%,40%,80%,and 100%）were conducted for two years in Chengdu Plain in 2014 and 2015.All treatments used fertilizers one time as base fertilizer and the effects on wheat yield and component factors,economic benefit as well as nitrogen use efficiency were analyzed.【Result】The highest yield was obtained in T4 for both years.The yields were increased by 697.06 kg/hm^2（2014）,521.02 kg/hm^2（2015）compared with T1,and increased by 383.86 kg/hm^2（2014）and 400.43 kg/hm^2（2015）compared with T6.Addition of 20% to40% CRNF increased the net income compared with other treatments,and the increases were 16.73%-23.24%（2014）and 4.05%-14.31%（2015）compared with T1.Nitrogen application improved the yield components and T4 treatment was the best with the largest areas of flag leaf,the second leaf and top two leaves at mature stage.T4 treatment also had the highest nitrogen accumulation（from jointing stage to mature stage）,and the nitrogen content of grain was significantly higher than that of other treatments at mature stage.With the increase of CRNF ratio,NPP,NAE,NUPE,and NAUE increased at beginning and decreased afterwards with the peak in T4,while CRSN was in contrary.There was less difference in NHI among treatments.After harvest,with the increase of CRNF ratio,the soil nitrogen at different forms increased.The nitrate nitrogen,microbial biomass nitrogen,alkaline hydrolyzed nitrogen and total nitrogen were increased significantly by adding more than 40% CRNF,compared with T1.【Conclusion】Coated controlled release urea combined with conventional urea could increase the top two leaves area,enhance nitrogen accumulation and distribution of panicle in wheat,and improve the nitrogen use efficiency and yield.The optimum CRNF ratio was 20%-40% in Chengdu Plain.