宁南旱区春玉米生物量、氮素利用及产量对常规/控释尿素配施的响应

Responses of Spring Maize Biomass Accumulation,Nitrogen Utilization and Yield to Combined Application of Conventional and Controlled Release Urea in Arid Regions of Southern Ningxia

为解决宁夏南部旱区全膜覆盖春玉米生育后期土壤供氮不足及减产等问题,以‘先玉698’春玉米为试材,研究常规/控释尿素配施对全膜覆盖春玉米干物质积累、氮素吸收利用及产量的影响。试验于2016—2017年在宁夏固原市彭阳县进行,以不施肥为对照(CK),设置T1(常规尿素基施N 150 kg·hm^-2+小口期追施N 75 kg·hm^-2)、T2(控释尿素基施N 75 kg·hm^-2+常规尿素基施N 75 kg·hm^-2+小口期追施常规尿素N 75 kg·hm^-2)、T3(控释尿素基施N 150 kg·hm^-2+常规尿素N 75 kg·hm^-2)、T4(控释尿素基施N 225 kg·hm^-2)4个氮肥配施处理。结果表明,与单施常规尿素相比,常规尿素与控释尿素不同比例配施能提高玉米收获期及花后的干物质量,干物质积累过程中的最大干物质积累速率(Gmax)和干物质达最大积累速率时的生长量(Wmax)。与其他处理相比,控释尿素配施常规尿素处理下2 a均提高玉米植株氮素吸收量,并促进氮素向籽粒转移,氮肥农学利用效率平均增幅为20.26%~60.15%(T3),肥料贡献率平均提高12.29%~49.15%(T2);不同配施处理中,2 a分别以T3、T2获得最高产量,平均每年较T1处理和T4处理分别提高8.82%、4.48%和7.59%、1.58%,穗粒数和百粒质量的增加是其增产的主要原因。因此,合理的氮肥配施(T2、T3)有利于提高玉米的生物量和氮素利用效率,可作为宁南山区高效增产的施肥措施。

In order to solve the problems of insufficient nitrogen supply and drop of yield at the late growth stage of full-membrane spring maizein the arid region of Southern Ningxia,an experiment was conducted in Pengyang county in Guyuan of Ningxia from 2016 to 2017.Four nitrogen treatments were used to determine the effects on dry matter accumulation,nitrogen uptake and the yield of full film-mulching spring maize.The four treatments were T1,applying urea(U)as basal fertilizer by N 150 kg·hm^-2+U top dressing at V10 by N 75 kg·hm^-2;T2,controlled-release urea(CRU)as basal N 75 kg·hm^-2+U as basal N 75 kg·hm^-2+U topdressing at V10 by N 75 kg·hm^-2;T3,CRU as basal N 150 kg·hm^-2+U as basal N 75 kg·hm^-2;and T4,CRU as basal N 225 kg·hm^-2.No fertilization was used as the control.The cultivar‘Xianyu698’was used as material.The results showed thatrational applications of CRU combined with U could increase the dry matter accumulation of maize at the mature and post-flowering stages,the maximum rate of dry matter accumulation(Gmax)and the weight of growth at the time of themaximum rate of dry matter accumulation(Wmax)were compared with a single application of conventional urea.In two years,compared with other treatments,the application of CRU and U could increase the absorption of nitrogen by maize and promote nitrogen transfer to the grains,and it could increase the agronomic efficiency of the applied nitrogen(AEN)of 20.26%–60.15%on average and increase the fertilizer contribution rate(FCR)of 12.29%-49.15%on average.Under different conditions of application,T3 and T2 respectively obtained the highest yields in two years,the average yield was higher than in T1 and T4 and increased by 7.59%and 1.58%in T2 and by 8.82%and 4.48%in T3.The increase of the spike grain number and grain weight were the main reason to increase yield.Accordingly,the reasonable application of nitrogen fertilizer(T2,T3)could be beneficial to increase biomass accumulation and nitrogen utilization efficiency in spring maize,and could be a measure for increasingmaize yield in the arid region of Southern Ningxia.