Effect of Water Irrigation Amounts and Nitrogen Fertilizer Levels on Teosinte Productivity and Optimal Economic N-Rates Under Salinity Stress

Abstract

The teosinte plant is one of the most important fodder crops that is affected by drought and nitrogen supply, and therefore the optimal supply of N- fertilization may be affected by the amount of irrigation water added to teosinte plants to obtain an economic crop. Two field experiments were done to study the effect of irrigation amount at three levels (100%, 80% and 120%) and nitrogen fertilizer levels (60, 90 and 120 kg N fed-1) (Feddan = 4200 m2) on the yield productivity of teosinte and determined the optimal and economic optimal N rate as affected by irrigation amount levels, and water relations. The results showed that the highest values of the fresh and dry weight of cuts, as well as plant height and stem diameter, were obtained when applying the full irrigation rate with full irrigation and 120 kg N fed-1. The results also showed that a 20% decrease in the irrigation rate led to a deterioration in the values of those parameters. Although the results showed that the full irrigation amount more saved water at two seasons under various levels of nitrogen. Moreover, all water relationships gave the best mean values for actual evapotranspiration, water utilization and use efficiencies also, higher application efficiency values at full irrigation and 120 kg N-levels than the other treatments. Also, the results showed that the economical yield of teosinte fresh cuts when using 211.01 kg N fed-1 with 120% of the recommended irrigation rate was higher when using 148.22 kg N fed-1 with the recommended irrigation rate. Therefore, we recommend using 211.01 kg N fed-1 to get an optimum economic yield of teosinte fresh cuts, especially in saline soil, with 120% of the recommended irrigation rate.