Nitrogen use efficiency, yield and yield traits of wheat response to slow-releasing N fertilizer under balanced fertilization in Vertisols and Cambisols of Tigray, Ethiopia

The study was initiated to investigate the effects of slow nitrogen-releasing fertilizer (UREA(Stabil)) on yield, yield components and nitrogen use efficiency indices of bread wheat at Emba Alaje and Hawzien Districts in Tigray, Ethiopia in 2015 at six farmers' field and arranged in a randomized complete block design with three replications. Treatments were four levels of nitrogen (0, 32, 64 and 96) kg ha(-1). The nitrogen source was UREA(Stabil), which is slow N-releasing fertilizer. Conventional urea at the recommended rate (64 kg N ha(-1)) was included as a positive control at both sites. A full dose of UREA(Stabil) were applied at planting while prilled urea (conventional urea) was applied in two splits 1/3 at planting and 2/3 at tillering. Application of UREA(Stabil) significantly influenced yield and yield components at both soil types. The highest grain yield was obtained on plots treated with 64 kg N ha(-1) in the form of UREA(Stabil) and prilled urea (conventional urea) in Hawzien and Emba Alaje districts, respectively. The highest nitrogen uptake was recorded on plots treated with 64 kg N ha(-1) in the form of UREA(Stabil) and prilled urea (conventional urea) in Hawzien and Emba Alaje, respectively. Nitrogen uptake, agronomic, physiological and apparent recovery efficiency were significantly influenced by the application of slow-releasing and conventional nitrogen fertilizers at both sites. In Hawzien, the application of slow-releasing N fertilizer in the form of UREA(Stabil) reduces the amount of N used and application time. Hence, it could be concluded application of slow-releasing fertilizer could be used as an alternative source of nitrogen for wheat production in the study site.