Evaluation of varietal response of soybean (Glycine max L. Merrill) to nitrogen (N) fertilization in Tashkent, Central Asia

摘要

A field experiment was conducted under the continental climatic conditions of Tashkent, Uzbekistan to evaluate the response of 3 soyabean cultivars to fertilizers. The rates of N fertilizer were 0, 50, 100, 150, 200 and 250 kg/ha as ammonium sulfatewith 120 kg/ha P2O5 as single superphosphate and 90 kg K2O/ha as potassium chloride. The growth parameters of cultivars Yuldus, Dustlik and Uzbekskaya 2 responded positively to N fertilizer application. Optimum plant height was achieved at 150 kg N/ha.The number of leaves increased linearly with the increase in the N rate but decreased significantly at N rates exceeding 100 kg in all the cultivars. The plant density of the cultivars was increased by increased N application except at 250 kg N. Optimumpod yield was obtained at 150 kg N/ha. Similarly, seed yield increased with increase in N rates, with optimum yields of 3.1-4.0 tons/ha with 100 and 150 kg N/ha.