Effect of Nitrogen Fertilizer and Zinc Sulfate on Quantitative and Qualitative Yield of Forage Maize under Deficit Irrigation Stress

<p>In order to investigate the effect of nitrogen and zinc sulfate fertilizers on the quantitative and qualitative yield of forage maize under low irrigation stress, this experiment was conducted as a split-factorial randomized complete block design with 4 replications in Ilam province during the two crop years of 2019 and 2020 was implemented. Three levels of irrigation including full irrigation (control or 90% of field capacity), irrigation based on 75% of field capacity (25% soil moisture discharge) and irrigation based on 50% of field capacity (50% soil moisture discharge) in the main plots Done. Factorial wetting of three levels of nitrogen from urea source, including zero (control), 150 and 300 kg ha-1 urea fertilizer; and foliar application of zinc sulfate at 3 levels of 0, 2 and 4 per thousand as the second factor in random was randomized. The results of combined analysis of variance showed that the interaction of year deficit irrigation stress&times;foliar application of zinc sulfate and the interaction of year deficit irrigation stress&times;nitrogen on total fresh yield were significant. The interaction of year deficit irrigation stress, year. Nitrogen fertilizer, year and foliar application of zinc sulfate, low irrigation stress&times;foliar application of zinc sulfate and the interaction of low irrigation stress&times;nitrogen fertilizer on the concentration of digestible dry matter were significant. Wet forage yield in full irrigation and consumption of 150 kg urea per hectare was 77728 kg.ha-1. Wet forage yield was obtained in complete irrigation treatment and consumption of 4 per thousand zinc sulfate in the amount of 78163 kg.ha-1. At irrigation levels based on the presence of 75% and 50% of field capacity, consumption of 4 per thousand zinc sulfate increased this index, so that in the mentioned treatments wet yield was obtained at 67460 and 49855 kg.ha-1, respectively. Irrigation treatment based on 50% of field capacity, application of 300 kg of urea fertilizer and 2 per thousand zinc sulfate resulted in grain protein content of 8.6%. Due to the lack of significant differences between treatments 2 and 4 per thousand zinc sulfate in different levels of nitrogen fertilizer, so the use of 300 kg of urea fertilizer per hectare and 2 per thousand zinc sulfate has good performance and economic justification and as the superior compound was selected to counteract the harmful effects of dehydration.</p>