The Examination of the effects of different irrigation waterquality and leaching fractions applied in the different growth stages of cotton

This study was done with the aim to determine the effects of irrigation water which have different EC on the salt resistance of cotton, depending on the relationships between water-salt level-leaching fraction and biomass. The experiment was conducted at the research field of the Department of Agricultural Structure and Irrigation, Agricultural Faculty, University of Çukurova, Adana in 1997 and 1998. In this study, the line source sprinkler irrigation technique was used and during irrigation events, different amount water and salt were applied to the plants. Three growth stages namely vegetative, flowering and ball formation, and ball opening, were taken into consideration and different leaching and different amount of water were applied at each growth stage. As a result of this, in the 7 main treatments with 28 and 21 irrigation levels for the first and second years, respectively, were obtained. According to the results, it was determined that the irrigation water with different EC affected the yield and biomass of cotton, especially, the growth stages were affected by different water and salt levels. Evapotranspiration and yield of cotton decreased when the salt content of irrigation water increased. The salt content in irrigation water caused salt accumulation in the soil however both winter rainfall and leaching decreased this salt accumulation in the soil. It was found that the salt removed from the soil was lower in the treatments in which high leaching fractions were used. Key Words: Salinity, Irrigation Water, Drainage Water, Cotton, Leaching Fraction n