硫包衣缓释肥提升水稻产量及氮肥利用率的技术途径OA

[Objective]Sulfur-coated slow-release fertilizers comprise four nitrogen(N)products with distinct release periods.This study aimed to determine whether these products should be applied individually or in combination,whether they should be blended with quick-release N fertilizers,and how to optimize their application to synergistically improve rice yield and nitrogen use efficiency(NUE).[Method]The field experiments were conducted in Yangzhou and Changzhou,Jiangsu Province from 2022 to 2024,using rice cultivars Nanjing 9108 and Nanjing 46 as test materials.The trials included comparisons of slow-release N products,screening of optimal product combinations,evaluations of fertilizer types,blending ratios of slow-and quick-release N fertilizers,and application timing of quick-release N,and optimization of slow-release N formulations.The effects of sulfur-coated slow-release fertilizer application methods on rice yield formation and nitrogen uptake and utilization were analyzed.[Result](1)The rice yield under the straw return treatment increased by 4.50%and 8.88%compared with the half-straw return and no-straw return treatments,respectively.Additionally,the nitrogen use efficiency(NUE)under the straw return treatment was 11.35%and 25.64%higher than that under the other two treatments,respectively.(2)The rice yield of the 60-day slow-release nitrogen product was 4.10%,15.68%,and 19.09%higher than that of the 30-day,90-day,and 120-day products,respectively,but 4.13%lower than that of the conventional precise fertilization.Overall,the NUE of the 60-day product exceeded that of other slow-release nitrogen products by an average of 8.68%.Under no-straw return and half-straw return conditions,the NUE was 9.88%and 0.93%higher than that under conventional precise fertilization,respectively;however,under full straw return,it was 4.57%lower.(3)The combination of slow-release nitrogen products in the ratio of 3+6+9 achieved the highest rice yield and NUE,yet both were lower than those of the conventional precise fertilization.(4)The treatment with a blending ratio of 7︰3(slow-to quick-release nitrogen)achieved the highest rice yield,nitrogen accumulation,and NUE,averaging 4.31%,3.25%,and 6.15%higher than that under conventional precise fertilization,respectively.Under this treatment,applying quick-release fertilizer as tillering fertilizer(for medium-duration varieties)or panicle initiation fertilizer(for long-duration varieties)synergistically improved yield,nitrogen accumulation,and NUE.The yield increase was primarily attributed to a significant enhancement in spikelets per panicle on the basis of adequate panicle number.(5)When slow-release nitrogen products were blended at a ratio of 30-day︰60-day︰90-day=1︰4︰1,rice yield,nitrogen accumulation,and NUE all achieved the highest values,averaging 3.76%,5.66%and13.35%higher than conventional precise fertilization,respectively,which was closely associated with significant increases in leaf area index(LAI),sink capacity,and biomass yield.[Conclusion]A blended slow-release N fertilizer was formulated by combining three controlled-release fertilizer with dissolution periods of 30 d,60 d,and 90 d at a 1︰4︰1 mass ratio.Application of this blended slow-release N with quick-release N at a 7︰3 ratio—implemented through one-time basal application of slow-release fertilizer and single topdressing of quick-release N as either tillering fertilizer(for 150-day varieties)or flowering-promoting fertilizer(for＞160-day varieties)—significantly increased grain yield by 3.76%and nitrogen use efficiency by 13.55%compared with conventional precision quantification.This field-validated protocol demonstrates sulfur-coated fertilizers enabled synergistic gains in rice productivity and nitrogen utilization efficiency.