Wheat Yield as Influenced by Nitrogen Rates, Sources and Tillage Systems
M. J. Bahrani *
Department of Crop Production and Plant Breeding, School of Agriculture, Shiraz University, Shiraz, Iran.
M. Davoodi
Department of Crop Production and Plant Breeding, School of Agriculture, Shiraz University, Shiraz, Iran.
S. A. Kazemeini
Department of Crop Production and Plant Breeding, School of Agriculture, Shiraz University, Shiraz, Iran.
*Author to whom correspondence should be addressed.
Abstract
Conservation tillage systems present a challenge for integrating an efficient fertilizer program in wheat (Triticum aestivum L.) production. A 2-year (2011–2013) field experiment was conducted to evaluate wheat response to three tillage systems (conventional, reduced and no tillage) and four nitrogen (N) [(0, 60, 120, 180 kg ha-1), and two nitroxin rates (0, 180 kg ha-1)] at School of Agriculture, Shiraz University, Shiraz, Iran. The experiment was conducted as a split plots arranged in randomized completely blocks design with three replications. Results showed that grain yield and most of the yield components were significantly influenced by tillage systems, N rates and sources. Nitroxin inoculation did not accomplish significant difference in grain yield, but it increased grain yield when it was applied with 180 kg urea ha-1 compared to no nitroxin treatment. The highest grain and biological yields were obtained when crop was sown under reduced tillage (RD) system combined with 180 kg ha-1 of nitroxin inoculation. Therefore, for sustained production of wheat in the region, integration of 180 kg ha-1 of nitroxin inoculation under RD system is recommended.
Keywords: Biological fertilizers, conservation tillage, nitrogen availability