EFFECTS OF IRRIGATION FREQUENCY ON SALT REGIME AND COTTON GROWTH UNDER MULCHED DRIP IRRIGATION

Xinjiang, located in west part of China, is the biggest cotton production region of thecountry, with acreage of about 1 million ha planted annually. The area under mulched drip irrigationamounts for 100,000 ha. This study investigated the influences of irrigation application frequencieson the soil salt regimes and cotton growth, under mulched drip irrigation of soils of different salinity.Field experiments were arranged with the following treatments: 2 levels of soil salinity (0.08% and0.8%), 2 irrigation application frequencies (one irrigation every 2 and 6 days during the stage ofblooming-bolling ). Records were made on spatial and temporal soil moisture and salt distributionsand the growth and yields of cotton. The experimental results showed that with the same amount ofwater irrigated, higher frequency irrigation to the soil of higher salinity during the stage of bloomingbollingeffectively reduced the salinity level of the wetted soil body and increased yield by 28%.While the higher frequency of irrigation had no significant impacts on the growth and yield of cottongrown in the soil of lower saline level.