تاثير تنش كم آبي و كود نيتروژن بر عملكرد و راندمان مصرف آب سورگوم و ارزن علوفه اي

The effect of drought stress and nitrogen levels on yield and water use efficiency of forage millet and sorghum

In order to evaluation of different irrigation and nitrogen levels on yield and yield components and water use efficiency of forage millet (cv. Notrifeed) and sorghum (cv. Speedfeed), an experiment was conducted in agricultural research station of Islamic Azad university of Birjand in 2005. Experimental design was split-split plot based on randomized compelet block design in three replications. The main plots were three irrigation levels (33, 67 and 100 precent of water requirment), sub plots were three nitrogen levels (46, 92 and 138 kg/ha) and sub-sub plots were plant species (forage sorghum and millet). The results showed that the effect of irrigation and nitrogen treatments and plant were significant at 0.01 confidence level on total fresh and dry yield and water use efficiency. The dry forage yield in 33 and 67 percent water requirement treatments were 62.6 and 15.5 percent lower than 100% water requirement treatment, respectively. The highest water use efficiency was belonge to medium water stress. Also total fresh and dry yield of forage and water use efficiency in millet were greater than sorghum. In addition, interaction between irrigation and nitrogen fertilizer in mentioned traits was significant at 0.01 confidence level. Application of higher levels of nitrogen increased total fresh and dry yield of forage and water use efficiency at all irrigation levels, significantly.