Effect of Controlled Drainage on Reducing Drainage Coefficient and Drainage Volume in Sugarcane Fields of Imam Khomeini Agro- industry

Sugarcane is one of the high consumption plants that has very high drainage coefficient. Irrigation frequency of Sugarcane in the maximum of consumption month is near 5 days and drainage systems often are removing drain water more than enough from the soil. This study was carried out to investigate the impact of controlled drainage on reduction of drainage coefficient and drainage volumes in three fields of Imam Khomeini sugarcane agro- industry. Two treatments were controlled drainage with water table controlling in 70 and 90 cm depth from soil surface (CD70، CD90) and the third one was free drainage (FD) treatment. According to the results، the CD treatments significantly reduced drainage coefficient during the study، compared to free drainage treatment. Average drainage coefficient in during the study in CD70، CD90 and FD treatments was 3، 4. 12 and 8. 98 mm/day respectively. Controlled drainage treatments (CD70، CD90) reduced drainage coefficient by 67% and 54% respectively، compared to free drainage treatment. CD70 treatment reduced drainage coefficient by 27%، compared CD90 treatment، too. The use of controlled drainage did not limited for plant growth and did not reduce sugarcane yield. Using of this method، in addition to the economic benefits will cause decreasing river pollution load and has a positive environmental impact.