优化缓释氮肥与尿素配施比例提高冬小麦产量和氮肥利用效率

为探究匹配冬小麦氮素需求规律的最佳缓释氮肥与尿素配施比例，优化施肥结构，达到氮肥高效利用与经济效益“双赢”的目标，该研究以冬小麦为研究对象，通过2 a(2019—2020年和2020—2021年)田间试验，设置7个施肥处理：仅施尿素(U)、仅施缓释氮肥(S)、缓释氮肥与尿素1:3配施(SU1)、缓释氮肥与尿素1:1配施(SU2)、缓释氮肥与尿素3:1配施(SU3)、不施氮肥(N0)和不施肥(CK)，研究缓释氮肥配施比例对冬小麦干物质积累和转运、产量和氮肥利用效率的影响。结果表明，冬小麦干物质快速生长期和最大累积速率随缓释氮肥配施比例的增加而增加，缓释氮肥与尿素配施的冬小麦干物质平均累积速率比普通尿素提高1.90%～19.91%。缓释氮肥与尿素配施可在改善花前干物质转运量的同时提高花后生产量，花后干物质生产量对籽粒贡献率达53.18%～71.83%。产量随缓释氮肥配施比例的增加而显著提高，SU3处理2 a产量分别为7 243和8 021 kg/hm²，较S和U处理分别提高了7.25%和16.07%，其经济效益较S和U处理提高了15.18%和25.67%。与仅施尿素相...

Combined the application of slow-release N fertilizer and urea to improve the yield and N use efficiency of winter wheat

Here, the best ratio of slow-release nitrogen fertilizer to urea was determined to match the nitrogen demand of winter wheat. The fertilizer application structure was also optimized for the efficient use of nitrogen fertilizer and economic benefits. Seven fertilizer treatments were applied into the winter wheat in a two-year field trial: urea only (U), slow-release N fertilizer only (S), slow-release N fertilizer with the urea 1:3 (SU1), 1:1 (SU2), and 3:1 (SU3), no N fertilizer (N0) and no fertilizer (CK). A systematic investigation was made to explore the effects of slow-release N fertilizer application rates on the dry matter accumulation and transport, yield, and N fertilizer use efficiency of winter wheat. The results showed that there was an increase in the rapid growth period and the maximum accumulation rate of dry matter in the winter wheat with the proportion of slow-release N fertilizer. The average dry matter accumulation rate of slow-release nitrogen fertilizer combined with the urea increased by 1.90% to 19.91%, compared with the ordinary urea. The proportion of slow-release nitrogen fertilizer application posed a significant impact on the post post-flowering dry matter production. There was an increase in the pre and post post-flowering dry matter transport. Meanwhile, the post post-flowering dry matter production was contributed 53.18% to 71.83% of the grain yield. The yield increased significantly with the increasing proportion of slow-release N fertilizer, with the two-year yields of 7 243 and 8 021 kg/hm2 in the SU3, which were 7.25% and 16.07% higher than the S and U treatments, respectively, and their economic benefits were 15.18% and 25.67%, respectively. The cumulative nitrogen uptake of winter wheat increased by the application of slow-release nitrogen fertilizer with the urea. Specifically, the cumulative nitrogen uptake values were 24.08% to 36.63% higher than those in the SU3, compared with the U treatment. The slow-release N fertilizer with the urea was improved the N fertilizer use efficiency. The agronomic use efficiency, physiological use efficiency, and biased productivity were improved by 130.39%, 70.96%, 58.33%, and 23.05%, respectively, in the SU3, compared with the U treatment. But there was no significant difference between SU2 and SU3 treatments (P>0.05). The slow-release N combined with the urea was significantly improved the N use efficiency, but there was no significant difference between SU2 and SU3 treatments (P>0.05). Therefore, the slow-release N fertilizer mixed with the urea can be expected to improve the winter wheat yield and N use efficiency. The dry matter growth period was significantly extended to promote the maximum accumulation rate for the post-flowering dry matter production and its transport rate to the seed. The fitting analysis showed that the high yield of winter wheat was achieved with 55% of slow-release N fertilizer in the combination with urea under the condition of 180 kg/hm2 of N application. Among them, the yield was 7 563 kg/hm2, and the nitrogen absorption efficiency was 50.23%. Agronomic utilization rate, physiological utilization rate, and partial production rate were 17.57, 31.97, and 43.59 kg/kg, respectively. The finding can provide the theoretical basis for the rational fertilization of winter wheat. Follow-up studies need to consider the environmental effects and carbon and nitrogen emissions, together with the impact of slow-release nitrogen fertilizer combined with the urea on the soil nitrate nitrate-nitrogen distribution, ammonia volatilization, and greenhouse gas emissions. Further research can be conducted to determine the amount and proportion of slow-release nitrogen fertilizer and urea application for the high yield, high efficiency, and simultaneous emission reduction in winter wheat farmland..