控释掺混尿素对稻麦产量及氮素利用率的影响

【目的】为了探究控释掺混尿素对稻麦产量及氮素利用率的影响,并分析不同氮肥处理下稻麦生长差异及原因,【方法】采用稻麦轮作两季作物大田试验,共设7个处理,包括不施氮CK处理、常规施肥以及掺混控释氮肥10%、20%、40%、80%、100%(依次记为CK,T_1、T_2、T_3、T_4、T_5和T_6处理),探讨了控释掺混尿素对稻麦干物质积累与分配、干物质增长速率、氮素积累与分配、产量与产量构成因子以及氮素利用率的影响。【结果】掺混控释氮肥20%以上对稻麦生育中后期干物质与氮积累有明显促进作用。但稻麦成熟期干物质与氮分配均呈现出掺混80%以上控释氮肥处理穗部分配明显较少,而茎、叶分配相对较多的特征,表现出一定程度的茎叶徒长,贪青晚熟趋势。添加20%以上比例控释氮肥均具有显著增产的效果,掺混40%控释氮肥处理分别比常规施肥处理增产14.23%(小麦)和10.93%(水稻),分别比单施控释氮肥处理增产7.37%和3.83%。稻麦季随掺混比例增加,氮肥偏生产力、氮肥农学利用率、氮素吸收效率、氮肥表观利用率均呈先增加后减少趋势,以掺混40%控释氮肥处理最优。各施氮处理均以单施控释氮肥处理的氮收获指数最低,小麦与水稻季分别较常规施肥处理下降了3.99%和8.51%。稻麦季土壤氮依存率随掺混比增加呈先下降后回升趋势,且均以掺混40%控释氮肥最低,分别比常规施肥处理下降了14.38%(小麦)和15.84%(水稻)。【结论】控释掺混氮肥处理可协调稻麦氮素吸收与分配,有利于作物生长发育,达到增产和提高氮素利用效率的作用,综合各因素以20%~40%掺混比例为佳。

Effects of Controlled Release Blend Bulk Urea on the Yield and Nitrogen Use Efficiency of Wheat and Rice

【Objective】A field experiment was conducted to investigate the effect of controlled-release fertilizer(CRF) combined with urea(UR) on the yield, nitrogen use efficiency and growth in wheat-rice rotation system. 【Method】Seven fertilization patterns including non- N fertilization(CK), farmers’ practice(T1), 10% CRF+90% UR(T2), 20% CRF+80% UR(T3), 40% CRF+60% UR(T4), 80% CRF+20% UR(T5), 100% CRF(T6) were applied to test the effect of different nitrogen treatments on dry matter accumulation and distribution, the growth rate of dry matter, nitrogen accumulation and distribution, yield and yield components, nitrogen use efficiency.【Result】 The dry matter and nitrogen accumulation in the mid-late stage of wheat and rice increased under the treatment with over 20% of controlled release fertilizer. Over 80% CRF addition decreased the dry matter and nitrogen accumulation in rice panicles, but increased accumulation in the stem and leaf, which resulted in late-maturing. Compared with T1, the yield was increased significantly with over 20% CRF addition, especially in the T4 treatment. The yield of wheat was increased by 14.23% and for rice, by 10.93%. Compared with T6, the yield of wheat increased by 7.37% and for rice, by 3.83% respectively. With the increasing CRF addition ratio, the nitrogen partial productivity(NPP), nitrogen agronomy efficiency(NAE), nitrogen uptake efficiency(NUPE), nitrogen apparent utilization efficiency(NAUE) increased both in wheat and rice at beginning and decreased afterwards, with the peak in T4. In all the nitrogen treatments, the lowest nitrogen harvest index(NHI) was abserved in T6, the NHI of wheat and rice decreased by 3.99% and 8.51%, respectively. With the increasing CRF ratio, the contribution rate of soil nitrogen(CRSN) in both wheat and rice decreased at beginning and then increased, with the valley in T4. Compared with T1, the CRSN of wheat decreased by 14.38% and for rice, by 15.84% under T4 treatment. 【Conclusion】These results indicated that controlled-release fertilizer enhanced nitrogen absorption and distribution, promoted crop growth and development, as well as crops yield and nitrogen use efficiency. The rational addition ratio of CRF for wheat and rice production ranged frow 20% to 40%.