Comparing the Corn, Millet and Sorghum as Silage Crops Under Different Irrigation Regime and Nitrogen Fertilizer Levels

The present study carried out to evaluate the effects of irrigation regimes (control and water stress) and two nitrogen levels (0, and 112.5 kg ha −1 ) on dry matter yield and silage quality of proso millet, sorghum and corn plants in 2015–2016. Results showed that dry matter (DM) yields of millet, sorghum and corn plants decreased as a result of water shortage. Under both irrigation regimes, the highest DM yields were observed in sorghum. Water stress also reduced irrigation water use efficiency (IWUE) in millet and corn, while it had no significant effect on that of sorghum. Water shortage led to increases in acid detergent fiber (ADF) and neutral detergent fiber (NDF) in corn and sorghum, whereas no significant differences were observed in millet. Furthermore, water deficit resulted in decreased digestibility in corn and sorghum, while increased it in millet. Under normal irrigation, maximum digestibility was observed in corn, while under water stress, no significant difference was observed between corn and millet. Accordingly, it can be said that sorghum is the best option for planting in arid areas, which has the highest yield and is also acceptable in terms of quality. In addition, nitrogen application is recommended to improve IWUE and forage quality. But, because of its insignificant effect on DM yield under stress conditions, application of nitrogen under stress conditions should be tested at more levels to find out optimum amount of nitrogen use and prevent fertilizer loss.