推荐施肥量下控释肥替代普通尿素提高高粱产量和氮肥生产力

Replacing common urea with controlled-release fertilizer at the recommended rate increases the yield and nitrogen fertilizer productivity of sorghum

【目的】高粱生产中氮肥施用不合理,氮肥利用效率低,研究适宜重庆地区高粱种植的控释氮肥减施比例,在减少氮肥用量的同时,确保高粱稳产高产,提高肥料利用效率。【方法】田间定位试验于2021、2022年在重庆永川进行,供试高粱品种为晋渝糯3号和金糯粱1号。设置6个处理,分别为不施氮肥(CK);习惯尿素施肥量(U,N 180 kg/hm^(2));尿素推荐施用量(U1,减N 20%,N 144 kg/hm^(2));控释氮肥减施氮量20%(C1,N144 kg/hm^(2));控释氮肥减施氮量30%(C2,N 126 kg/hm^(2));控释氮肥减施氮量40%(C3,N 108 kg/hm^(2))。在高粱开花期和成熟期,调查干物质积累量和转运量,成熟期调查植株和籽粒氮素含量、生物量、产量及产量构成因素。【结果】开花期和成熟期高粱干物质积累量均以C1和U1处理最高,C1处理成熟期干物质积累量又显著高于U1。C1处理叶片花前干物质转运量显著高于U。花后干物质积累量C1处理显著高于其他处理,U1和C2处理显著高于U处理。C1处理晋渝糯3号和金糯粱1号花后干物质积累量对籽粒的贡献率较U分别显著提高了11.54%和12.41%。C1处理的高粱产量最高(晋渝糯3号6611 kg/hm^(2),金糯粱1号5690 kg/hm^(2)),较其他施氮处理显著提高了5.40%~18.66%;其次为C2和U1处理,二者的产量均显著高于U和C3处理。各施氮处理的氮肥生理利用率(NPE)差异不显著;减氮处理间氮肥农学利用率(NAE)无显著差异,氮肥偏生产力(NPFP)差异显著,其NAE和NPFP均显著高于习惯施氮处理U;控释肥各减氮处理的NPFP显著高于普通氮肥推荐量处理U1。C1处理较U处理大幅提高了NAE、NPFP和氮肥利用率(NUE),晋渝糯3号分别提高了58.54%、39.61%和59.28%,金糯粱1号分别提高了80.97%、48.30%和63.08%;与U1处理相比,晋渝糯3号的NPFP、NUE分别提高了5.38%和22.19%,金糯粱1号分别提高了5.82%和4.42%。【结论】推荐施氮量下,用控释肥替代普通氮肥增加了高粱开花期和成熟期干物质积累量,提高了叶片花前干物质转运量和花后干物质积累量及其对籽粒的贡献率,提升了高粱产量和氮肥利用效率,可作为西南地区高粱生产的推荐氮肥施用方式。

【Objectives】We studied the availability and suitable rate of replacing common urea with controlled-release fertilizer in sorghum production,to propose a reasonable and efficient fertilization method.【Methods】A field experiment was conducted in Yongchuan,Chongqing in 2021 and 2022,and the test sorghum varieties were Jinyunuo 3 and Jinnuoliang 1.Six treatments were set up,namely no nitrogen fertilizer(CK);ordinary urea at N rate 180 kg/hm^(2)(U),ordinary urea at N rate of 20%less than U(U1,recommended N rate);controlled-release nitrogen fertilizer at N rate of 20%less(C1,recommended N rate),30%less(C2),and 40%less(C3)than U.The sorghum dry matter accumulation(DMA)at anthesis and mature stages,yield and its components at mature stage were investigated.【Results】The DMA of C1 and U1 at anthesis and mature stages were significantly higher than those of the other treatments,and the DMA of C1 was significantly higher than that of U1 at mature stage.The transport of leaf dry matter before anthesis of C1 treatment was significantly higher than that of U.The DAM after anthesis in C1 treatment was significantly higher than those in the other treatments,and those in U1 and C2 were significantly higher than that in U treatment as well.The contribution rates of DMA after anthesis to grain of C1 treatment were 11.54%and 12.41%higher than those of U for Jinyunuo 3 and Jinnuoliang 1,respectively.The yields of C1 treatment were the highest,6611 kg/hm^(2) for Jinyunuo 3 and 5690 kg/hm^(2) for Jinnuoliang 1,which were significantly increased by 5.40%-18.66%,compared with the other nitrogen treatments.The yields of C2 and U1 treatments were second-highest,significantly higher than those of U and C3 treatments.All the treatments exhibited similar nitrogen physiological efficiency(NPE).The four N reduction treatments exhibited similar nitrogen agronomic efficiency(NAE),but distinct nitrogen partial factor productivity(NPFP).The NAE and NPFP of the four N reduction treatments were significantly higher than those of U treatment.The NPFP of the three controlled-release N treatments were significantly higher than that of U1 treatment.Compared with U treatment,C1 treatment significantly increased NAE,NPFP and NUE by 58.54%,39.61%and 59.28%for Jinyunuo 3,and by 80.97%,48.30%and 63.08%for Jinnuoliang 1.The NPFP and NUE of C1 treatment were 5.38%and 22.19%higher than those of U1 treatment for Jinyunuo 3,and 5.82%and 4.42%for Jinnuoliang 1.【Conclusions】At the recommended N application rate,replacing common urea with controlled-release fertilizer could increase the dry matter accumulation at anthesis and mature stages,promote the transport of leaf dry matter before anthesis,enhance the dry matter accumulation after anthesis and its contribution to grain,thereby improve sorghum yield and nitrogen use efficiency significantly.Therefore,replacing common urea with controlled-release fertilizer at the recommended rate could be recommended as an efficient nitrogen fertilization method for sorghum production in southwest China.