Effect of fertilizer management and the application of zeolite on agronomic traits and grain yield of maize (Zea mays L.) hybrids under deficit irrigation conditions

Drought stress is considered as the most important limiting factor for growing of crops such as maize. Under low irrigation conditions, proper nutrition of plants can improve the effects of drought stress. This experiment was carried out in order to investigate the effect of nutrition management along with application of zeolite on agronomic traits of two hybrids of maize under deficit irrigation conditions in a field research in Soil and Water Research Institute in Karaj, Iran in 2015 and 2016 via a factorial split-plot plan based on a randomized complete block design with three replications. Experimental treatments included two levels of irrigation; full irrigation (I1) and deficit irrigation (70% of full irrigation) (I2) as the main factor and  factorial combination of fertilizer application at five levels; application of fertilizer in the conventional method (F1), fertilization application in conventional method + 10 tons of zeolite.ha-1 (F2), fertilizer application based on local recommendation (F3), fertilizer application based on local recommendation + 10 tons of zeolite.ha-1 (F4) and control (without fertilizer) (F5). Besides, maize hybrids including a late hybrid (SC704) (H1) and an early maturity hybrid (260 = Fajr) (H2) were considered as sub-factors. The results of analysis of variance showed that deficit irrigation had a significant effect on grain yield, number of grain.ear-1, ear weight, number of ear.m-2, and fertility of florets, while under deficit irrigation condition the values of these traits decreased. Under deficit irrigation treatment, the highest grain yield of maize hybrids (7934.3 and 7793.8 kg.ha-1 for 704 and 260 hybrids, respectively) was obtained from recommended fertilizer application + zeolite, which were 7% and 15% less than grain yield of corresponding maize hybrids (8180 and 9170.29 kg.ha-1 for 704 and 260 hybrids, respectively) where recommended application of fertilizer + zeolite were used under full irrigation condition. In general, the appropriate fertilizer management with the application of 10 tons of zeolite.ha-1 led to a higher grain yield of both late and early hybrids of maize and saving 30% water consumption (up to 2100 m3.ha-1).