Abstract:

To study the effects of one-off application of slow-release nitrogen （N） fertilizer or controlled release urea on yield， N utilization efficiency and economic benefits of summer maize in Huanghuai regions， field experiments with one-off fertilization of controlled release urea or slow release urea blended with normal urea were conducted at 6 experimental sites in Henan province in 2021. 9 treatments were set under field condition： no nitrogen fertilizer （CK）， normal urea alone （U1）， farmers’ fertilization practices （U2）， controlled release urea blended with normal urea （CRU） including 3 ratios of 3∶7 （CRU1）， 5∶5 （CRU2）， 7∶3 （CRU3） ， slow release urea blended with normal urea （LCU） including 3 ratios of 3∶7 （ LCU1）， 5∶5 （LCU2） and 7∶3 （LCU3）. The effects of controlled release urea or slow release urea blended with normal urea on yield， N utilization and economic efficiency of summer maize were studied. The results showed that N application treatments increased yield by 11.6%~49.1% compared with CK. The average yield of N application treatments was in the order of CRU>LCU>U（U1、U2）. The average yield of CRU and LCU was 23.3% and 9.7% higher than U， respectively， with CRU2 having the highest yield of 9 444.0 kg·hm^-2， 8.0%~33.6% higher than other N application treatments， followed by LCU2. Dry matter accumulation， grain number per spike and 1 000-grain weight were significantly higher under CRU and LCU treatments compared with U. The highest N recovery efficiency was 36.9% under CRU2 treatment， followed by LCU2 at 33.2%. Compared with U， CRU and LCU treatments had higher NO{}_{\mathrm{3}}^{-}-N content in 0—40 cm and significantly lower NO{}_{\mathrm{3}}^{-}-N content in deeper soils （40—100 cm）， which resulted in an average revenue increase of 2 186 and 995 yuan·hm^-2， respectively. The sustainable yield index of summer maize was correlated with high yield and coefficient of variation. CRU2 and LCU2 treatments had more stable yields and better sustainability. Combining yield， N utilization and economic efficiency， the N fertilizer management model of 5∶5 combination of controlled release urea and normal urea was recommended for one-off application in summer maize production in Huanghuai regions. Above results could provide a basis for simplified production techniques of summer maize and high yield and efficiency of N fertilizer.

Key words: summer maize, one-off fertilization, controlled release urea, slow release urea, yield, N utilization efficiency

摘要：

为研究一次性施用缓（控）释肥对黄淮夏玉米产量、氮肥利用率和经济效益的影响，于2021年在河南省6个试验点开展一次性施用控释尿素或缓释尿素配施普通尿素的田间试验。共设置9个处理：不施氮肥（CK），单施普通尿素（U1），农民习惯施肥（U2），控释尿素与普通尿素配施（CRU）包括3∶7（CRU1）、5∶5（CRU2）、7∶3（CRU3）3种比例，缓释尿素与普通尿素配施（LCU）包括3∶7（LCU1）、5∶5（LCU2）和7∶3（LCU3）3种比例。研究控释尿素或缓释尿素配施普通尿素对夏玉米产量、氮素利用和经济效益的影响。结果表明，施氮处理较不施氮增产11.6%~49.1%，平均产量表现为CRU>LCU>U（U1、U2），CRU和LCU平均产量较U分别提高23.3%和9.7%，其中CRU2产量最高，为9 444.0 kg·hm^-2，较其他施氮处理提高8.0%~33.6%，LCU2产量次之。CRU和LCU干物质积累量、穗粒数、千粒重较U均显著提高。CRU2氮肥表观利用率最高，为36.9%，LCU2次之，为33.2%。与U相比，CRU和LCU 0—40 cm NO{}_{\mathrm{3}}^{-}-N含量较高，深层土壤（40—100 cm）NO{}_{\mathrm{3}}^{-}-N含量明显降低，分别平均增收2 186和995元·hm^-2。夏玉米产量可持续性指数与产量高低、变异系数均相关，CRU2和LCU2产量较稳定，可持续性较好。综合产量、氮素利用和经济效益，推荐控释尿素与普通尿素5∶5配施的施肥模式在黄淮夏玉米生产上一次性施用。研究结果可为夏玉米轻简化生产和氮肥高产高效提供依据。

关键词: 夏玉米, 一次性施肥, 控释尿素, 缓释尿素, 产量, 氮肥利用效率