Effects Of Saline Water On Soil Water And Salinity Transport And Cotton Yield Under Drip Irrigation

[Object]Xinjiang is a typical inland arid area, agricultural production is completely dependent onirrigation,94%of the arable land is irrigated, agricultural water resources accounting for97%of total usage. Improving irrigation water use efficiency, rational development light andhigh-salinity water has become a national concern. Saline water instead of fresh waterresources can be used for agricultural irrigation, thus effectively reduce the shortage offreshwater resources crisis. This study was designed through years of field experiments,revealing saline drip irrigation soil salt distribution and accumulation characteristics, explorewater drip on cotton growth, nutrient absorption and yield, for the rational use of saline waterresource and provide theoretical basis.[Method].The distribution and accumulation of soil salinity in drip irrigated cotton fields wereinvestigated with a field experiment for two years. The effect of different water salinity onyield of cotton was also evaluated in this study. Three water salinity levels were set as0.35,4.61and8.04dS/m, representing fresh water, brackish water and saline water, respectively. Afield experiment was carried out to evaluate the effect of irrigation amount, water salinity andN application rate on the leaching of water, salt and N in soil and its impact on the cottongrowth under drip irrigation conditions.[Result](1) The differences of water content among three treatments increased with water salinityand irrigation period increased. The water content in0-100cm soil depth under saline watertreatment was significantly higher than those under fresh water and brackish water treatments.(2) With water salinity level increasing, the soil salinity increased. Soil salt mainlyaccumulated in the depth of0~20cm and80~100cm. The yield of cotton under saline watertreatment decreased significantly,(3) The leaching of water, salt and N from soil were increased as irrigation amount andwater salinity increased. Nitrogen application had little effect on the leaching of water and saltfrom soil, but made a significant difference to the dry matter weight of cotton.(4) Appropriate irrigation water salinity, irrigation amount and nitrogen fertilizer isbeneficial to reduce the leakage loss of the soil moisture and nitrogen，promote cotton growtjand increase the dry matter weight of cotton.[Conclusion]With water salinity level increasing, there were no significant differences betweenbrackish water and fresh water treatments. Light saline water has little effect on cotton yield，However, the high salinity water will lead to significant reduction in cotton production. Andthe yield decreasing range will be added year by year，Saline irrigation on cotton single bollweight has little effect, Leading bolls per plant decreased significantly. That says saline water have some value in use. When the salinity of irrigation water reaches a certain range willseriously affect cotton production can not be applied...