Crop evaportranspiration was studied with measured data of Kongque river irrigation district in Xinjiang Province based on application of BP neural networks, a sensitivity analysis about crop evaportranspiration was conducted according to each input factor by using default factor method, and the grey relational analysis method was applied to certify the results.The results showed that the artificial neural networks model could express quantitatively the response relationship between crop evaportranspiration and various factors with sufficient high accuracy. Soil moisture and solar radiation were the main sensitive factors for soil water-salt dynamic in this irrigation district, the interaction amongst various factors formed coupling relationship under the complicated condition. The grey relational analysis method could further verify the sensitivity degree amongst various factors. The combination of the above methods provides feasible method for analyzing the rules of crop water comsumption during crop growing season, and it is complement and perfection for the traditional research methods of crop evaportranspiration.

Salt transfer law for cotton field with drip irrigation under the plastic mulch was analyzed from two aspects: different postemergences and different direction (vertical direction and horizontal direction). The results show that with the retardation of postemergences, the accumulation of salt in 0-50cm soil layers decrease in different extent. The accumulation of salt in vertical direction increase at the soil layers from 50 to 70cm, but the one at the soil layers from 70 to 90cm change a little. The accumulation of salt in horizontal direction at the narrow row is more than any other position and the one under the emitter is least.