控释尿素与普通尿素配施对春玉米产量、氮肥利用及经济效益的影响

Effects of different ratios of controlled-release urea and common urea on yield,nitrogen utilization and economic benefit of spring maize

在黄土高原东部春玉米主产区连续3 a开展大田定点试验,设置不施氮(CK)、控释尿素与普通尿素不同配比:0(CRU0%)、25%(CRU25%)、50%(CRU50%)、75%(CRU75%)、100%(CRU100%)共6个施肥处理,研究控释尿素与普通尿素不同配施比例对春玉米产量、氮素利用和经济效益的影响,并建立控释尿素配施比例与产量、氮肥表观利用率和施肥收益之间的关系,以确定最佳配施比例,为筛选适于在黄土高原东部推广应用控释掺混配方肥提供科学依据。研究结果表明:(1)控释尿素与普通尿素配施能显著提高玉米产量,增加施肥收益,且随着配施比例的增加,2项指标均呈先增加后降低的趋势,其中CRU75%处理的春玉米产量和施肥收益最高,分别较CRU0%处理增加了1273 kg·hm^-2(11.9%)和1735元·hm^-2(65.7%)。(2)与CRU0%处理相比,控释尿素不同配施比例处理显著提高了玉米氮素利用率、农学效率和偏生产力,提高幅度依次为24.73%~43.87%、38.22%~61.24%和7.45%~11.93%,且均以CRU75%处理最高。(3)控释尿素与普通尿素配施处理显著降低了0~100 cm土层土壤中氮残留量和氮素表观损失量,CRU75%处理氮残留量和氮表观损失量最低,分别为119.8 kg·hm^-2和247.5 kg·hm^-2。(4)控释尿素配施比例与春玉米产量、氮肥表观利用率和施肥收益均存在显著一元二次关系,基于此3项指标推算出控释尿素的适宜配施比例分别为64.3%、71.2%和61.8%。控释尿素与普通尿素配合施用有利于促进春玉米生长发育,获得增产增收并提高氮素效率,综合各因素确定黄土高原东部春玉米生产的控释尿素适宜配比为60%~75%。

This research aimed to provide theoretical basis for the proportion of controlled-release blended fertilizers suitable for the eastern Loess Plateau,through the study of the effect of different blending proportions between controlled-release urea and common urea on the yield,nitrogen(N)utilization of spring maize and the economic benefit,and the identification of the optimal blending proportion through the establishment of the relationships between parameters including yield,apparent efficiency of N,profit resulting from fertilization and different blending proportions of fertilizers.Fixed-location experiment was carried out in the eastern spring maize producing area on the eastern Loess Plateau for three years consecutively.Six fertilizer treatments were arranged,including no N(CK),100%common urea(CRU0%),25%controlled-release urea,and 75%common urea(CRU25%),50%of controlled-release urea and 50%common urea(CRU50%),75%controlled-release urea and 25%common urea(CRU75%),and 100%controlled-release urea(CRU100%).The results showed that:(1)The yield of maize and fertilization profit were significantly increased after the combined application of controlled-release urea and common urea,and both rose firstly and then decreased with increasing the proportion of controlled-release urea.The highest yield and fertilization profit of spring maize were found in the treatment of CRU75%.The yield and fertilization profit in CRU75%increased by 1273 kg·hm^-2(11.9%)and 1735 yuan·hm^-2(65.7%),respectively,when compared to those in treatment CRU0%.(2)Compared with the treatment of CRU0%,the combined application of controlled-release urea and common urea significantly improved the N utilization efficiency,agronomic efficiency,and partial productivity of maize by 24.73%~43.87%,38.22%~61.24%,and 7.45%~11.93%,respectively,with the highest level found in treatment CRU75%.(3)Different combinations of controlled-release urea and common urea significantly reduced the residual N content and apparent loss of N in the soil layer of 0~100 cm,and the lowest values of both parameters were found in the treatment of CRU75%,which were 119.8 kg·hm^-2 and 247.5 kg·hm^-2,respectively.(4)On the whole,there was a significant unary quadratic relation between the yield of spring maize,the partial productivity of N fertilizer and the fertilization profits and the blending proportion of controlled-release urea.The appropriate blending proportions of controlled release urea were worked out as 64.3%,71.2%and 61.8%in terms of yield,partial productivity of nitrogen and fertilization profit,respectively.Combined application of controlled-release urea and common urea was beneficial to the growth and development of spring maize,the yield and income improvement,and N efficiency.According to the performance of all aspects,the optimal proportion of controlled-release urea in the blended fertilizer was 60%~75%for spring maize.