The Interaction Effect of Salinity, Drought and Harvesting Dates on Yield, Quality and Efficiency of Forage Sorghum in Subsurface Drip Irrigation (Case Study: Sistan Plain)

Forage sorghum is one of the tolerant salinity plants that can provide a good source of forage under irrigated conditions with saline water. Considering the quality of the products, their value is estimated with regard to their quality. Therefore, similar to many crops, the quality of forage plants should be considered. The quality of forage can be a function of forage consumption and its digestibility(Paterson et al., 1994). Forage plants in livestock trapping as a result of livestock production are undeniable in the supply of human needs. Unfortunately, in Iran, less attention is paid to the production and management of forage compared to other crops. As a result, lack of attention to the quantitative and qualitative increase of forage has led to a shortage of meat and dairy products and a decrease in their quality. Therefore, paying attention to the cultivation of forage plants with a scientific method in a country that is faced with the excessive growth of population and the shortage of rich meadows is very important (Noroozi et al., 2015). Sorghum is one of the important forage crops that is widely cultivated as summer forage in most of the dry and semi-arid countries of the world. Forage sorghum is used as green, dry, silage, or even for direct grazing of livestock (Rezvani moghaddam and Nasir mahallati, 2004). In thecurrent research, the effect of drought stress on sorghum was investigated. The results showed that the yield components including the number of seeds per plant and weight of 100 seeds decreased compared to the control (Innes and Black, 2001). Therefore, in this study, the effect of different levels of salinity and irrigation water and harvest on the yield of forage sorghum was investigated in order to use the results for proper planning to increase agricultural production in specific conditions, i.e., salinity and water restriction.