干旱区生态环境知识资源中心

The Tarim River Basin, the largest area of Chinese cotton production, is receiving increased attention because of serious environmental problems. At two experimental stations (Korla and Aksu), we studied the influence of salinity on cotton yield. Soil chemical and physical properties, soil water content, soil total suction and matric suction, cotton yield and water use efficiency under plastic mulched drip irrigation in different saline soils was measured during cotton growth season. The salinity (mS center dot cm(-1)) were 17-25 (low) at Aksu and Korla, 29-50 (middle) at Aksu and 52-62 (high) at Aksu for ECe (Electrical conductivity measured in saturation-paste extract of soil) over the 100 cm soil profile. The soil water characteristic curves in different saline soils showed that the soil water content (15%-23%) at top 40 cm soil, lower total suction power (below 3500 kPa) and lower matric suction (below 30 kPa) in low saline soil at Korla had the highest water use efficiency (10 kg center dot ha(-1)center dot mm(-1)) and highest irrigation water use efficiency (12 kg center dot ha(-1)center dot mm(-1)) and highest yield (6.64 t center dot ha(-1)). Higher water content below 30 cm in high saline soil increased the salinity risk and led to lower yield (2.39 t center dot ha(-1)). Compared to low saline soils at Aksu, the low saline soil at Korla saved 110 mm irrigation and 103 mm total water to reach 1 t center dot ha(-1) yield and increased water use efficiency by 5 kg center dot ha(-1)center dot mm(-1) and 7 kg center dot ha(-1)center dot mm(-1) for water use efficiency (WUE) and irrigation water use efficiency (IWUE) respectively.