Water has been identified as one of the scarce inputs, which can severely restrict agricultural production and productivity unless it is carefully conserved and managed. Increasing the adoption of irrigation technology is an important requirement for increasing Nigeria’s agricultural productivity. Farmers use the furrow irrigation method and fixed irrigation interval schedule for maize production in this region. The irrigation method used by the farmers has become unsustainable due to low yield, low water use efficiency, low quality of maize kernels and low net farm income. Thus, there is a growing gap between the demand for maize and its production to meet the food requirement for the growing population. The aim of this study was to determine the profitability of sprinkler irrigation method for maize production in semi-arid environment of Nigeria. Two field experiments were conducted in the 2014 and 2015 seasons at the Teaching and Research Farm of Ramat Polytechnic Maiduguri, Borno State which is located in the semi-arid region of Northern Nigeria. The sprinkler irrigation system used consisted of a reservoir, mainline and six laterals spaced 12 meters apart. Each treatment was irrigated using two laterals and each lateral has a control valve for regulating the flow of water.  Each lateral consisted of three double nozzle sprinklers spaced 6 meters apart along the lateral. The diameters of the mainline and the laterals were 101.6 and 31.75mm respectively. The area irrigated by the sprinkler system was cleared and marked out into plots of sizes 12m2. Scheduling was on the use of tensiometer, pan evaporation and fixed irrigation interval. Irrigation was conducted in the plots monitored by the tensiometer whenever the trigger level of 30cb is reached. The crops were irrigated at 1.0 IW/CPE ratio for optimum yield based on the evaporation pan method.  The profitability analysis result revealed that Sprinkler irrigation was found to be a profitable irrigation method for maize production with net farm income of $460.8 and benefit cost ratio of 1.99. Based on the results, it is recommended that farmers in the semi-arid region of Nigeria should use the sprinkler irrigation method for improved maize production.

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Lake Chad region is currently experiencing trending issues. Climate change is among the major influencers of these issues that require inevitable consideration for a sustainable ecosystem. Various crop models have been developed and employed in various environmental conditions and management practices, which are cheaper and easier than field experiments. Therefore, crop models could be used to simulate various water management strategies and suggest suitable options. In this work, the FAO AquaCrop model has been evaluated to simulate deficit irrigation (DI) scenarios for wheat crops using data generated from a field experiment. The model simulated grain yield (GY), biomass yield (BMY), biomass production (BMP) and canopy cover (CC) adequately during its calibration and validation. However, its performance in simulating water productivity (WP) and actual crop evapotranspiration (ETa) was low with average r2, NRMSE, model efficiency (EF) and Willmot Index of agreement (d) of 0.58, 11.0 %, -1.40 and 0.69 respectively. The study of DI scenarios using the model revealed that the application of DI throughout the growth stages of the crop could significantly affect GY and WP. The highest GY and WP of 5.3 t/ha and 1.50 kg/m3 were respectively obtained at the application of full irrigation (T100). Increasing DI beyond 20 % depressed both GY and WP significantly. However, increasing the irrigation interval from seven to ten days did not affect GY, thereby improving WP from 1.28 kg/m3 to 1.38 kg/m3. Therefore, applying an 80 % irrigation requirement throughout the wheat growing season at 10-day intervals could save 25 % of irrigation water, a valuable strategy to improve irrigation water use without significant yield reduction. Furthermore, irrigation-related scientists and managers can use the validated model to decide the current and future irrigation water management for similar wheat varieties in similar environmental conditions.