RESPONSE OF WINTER WHEAT (Triticum aestivum L.) TO IRRIGATION INTERVAL AND NITROGEN RATE AT SHASHOGO HADIYA ZONE, CENTRAL ETHIOPIA

Abstract

Winter wheat (Triticum aestivum L.) is one of the most exciting food grain crops grown under diverse agro ecological condition. It is considered to be the world's second important crop after rice. However, wheat productivity is affected by so many factors such as blanket nitrogen fertilizer application, similar irrigation interval for all types of soils, poor agronomic practices, and insufficient relevant technology generation and dissemination. Applying appropriate scheduling of irrigation water and balanced rate of nitrogen fertilizer are the main solutions to maximize wheat production in the study area. Therefore, the objective of the present study was designed to determine nitrogen fertilization levels and irrigation interval on growth, yield and yield components of winter wheat during 2023 cropping season at farmers training Centre of Shashogo, Central Ethiopia. The experiment consisted of four nitrogen rates (0, 69, 80.5 and 92 kg ha-1) and three irrigation intervals (11, 12 and 13 days). The treatments were laid out in a split plot design with three replications. Data on number of days to 50% heading and number of days to 75% physiological maturity, plant height, leaf area, leaf area index, spike length, number of kernel per plant, gain yield and above ground biomass, straw yield and harvest index were collected. Results of analysis showed that nitrogen fertilizer applied at 200 kg ha-1 and irrigation interval of 12 days resulted in the highest plant height, spike length, leaf area index, above ground biomass yield, number of spikelet spike-1, number of kernels spike-1 and weight of 1000 seeds, as compared to control and other treatments. The result of nitrogen use efficiency analysis showed that the highest agronomic efficiency (9.83) and partial factor productivity (26.74) were for 12days irrigation and at 69kg N ha-1 treatment. The highest water productivity (9.9kg mm-1) and grain yield (4467.59kg ha-1) were recorded due to application of 92kg N ha-1 for irrigation interval of 11 days. The same rate of nitrogen fertilizer application also gave the highest net benefit (116,003.1 Ethiopian Birr ha-1) and marginal rate of return (2427.78%). Therefore, it can be concluded that application of 92kg ha-1 nitrogen fertilizer for 13 days of irrigation interval would enable producers to harvest better wheat yield and get more economic return from the crop in the study area. However, further studies are required by including other nitrogen fertilizer rates and irrigation intervals by repeating the experiment over seasons and locations to come up with comprehensive recommendations