Effects of nitrogen and sulfur combined application on nitrogen use efficiency and grain yield of winter wheat

【Objectives】 Nitrogen (N) and sulphur (S) are essential nutrients required for all living organism, which play important role in grain yield and quality of wheat. Insufficient S, especially physiological deficiency S caused by large amounts of N supply, will result in decreased grain yield and diminished S amino acid content of the grain protein. This paper aims to compare the effects of different N and S combined application on the N use efficiency and grain yield of winter wheat and to give some reasonable advices about N and S fertilization technology in the North China Plain. 【Methods】 A wheat cultivar, Yumai49-198, was used as test material. Field experiments were conducted with five N levels of 0, 120, 180, 240 and 360 kg/ha (recorded as N0, N120, N180, N240, N360) and two S levels of 0 and 60 kg/ha (S0, S60) during wheat growth seasons. The dry matter accumulation (DMA), N accumulation and distribution, and grain yield formation were measured in 2012-2013 at Wenxian County in Henan Province, China.【Results】 The DMA at late growth stages is increased with the increase of N application rate. Under the same N application rates, S application could significantly increase DMA of winter wheat compared with no S application, in which at maturity stage the DMA of N180S60, N240S60 and N360S60 compared with N180S0, N240S0 and N360S0 increased 2225, 3607 and 3120 kg/ha, respectively, showing the order of N180S60 N240S0, N240S60 N360S0, and the differences all reach significant level. The total N accumulation in wheat plant also increased with the increase of N application rate, the S application could significantly increase the accumulation under higher N application rates (240 and 360 kg/ha). Compared with no S application, S application at five N application levels could also increase the grain yield by 10.5%, 18.3%, 5.2%, 5.6% and 4.9%, respectively. N partial factor productivity gradually declined with the increase of N application rates, N recovery efficiency, agronomic efficiency and physiological efficiency are all the highest in the N180 treatment, and combined with S application could further significantly increase the N recovery efficiencies, and the increases in agronomic efficiency and N partial factor productivity are significant at N application rates of 120, 180 and 240 kg/ha. 【Conclusions】Comprehensively considering grain yield and N use efficiency in the current wheat production of North China, we conclude that combined N and S fertilization is effective technology for achieving simultaneously high grain yield and N use efficiency of winter wheat. N of 180-240 kg/ha combined with S of 60 kg/ha are recommended to obtain stable and high yield and high efficiency of winter wheat in the tested area.