Regulation Of Soil Water-saline Movementing And Improve Tolerance Saline Effect Of Cotton Under Dirp Irrigation

Saline soil is important soil type, it is widely distributed in drought zero. Study on cotton of drought zero was mainly focused on soil water-saline movementing and growth,physiological indexs of cotton. However signal transmission of cotton root-plant system on saline soil in drought zero was little reported.The project will select cotton in saline soil Xin Jiang on drip irrigation（furrow irrigation）,（1） study the regulation of water-saline movementing in drought zero;（2）by using the root research, such as root shape indexs（root energy）, root nutrient absorption dynamics in saline stress,and to found the mechanism of cotton root in saline stress;（3） according to the reactive oxygen species（ROS, such as O₂^-,H₂O₂） and antioxidant enzyme system（SOD, POD,etc）, the project will found the mechanism of cotton root-plant system signal transmission in saline stress;（4） with the biology, agriculture, physiological indexs of cotton in different irrigation mode, the project will found the mechanism of cotton ecological response,adjust and control in Xin Jiang.The results of this research will supply science theoretical basic to study mechanism of cotton endure saline stress and reasonable development-utilization of saline soil. The main results are summarized below.1. The growth of cotton was defered in the saline soil,and the seedling rate、plant height、growth speed and width of leaf were decreased,the chlorophyll of leaf was below than the ck（no saline soil）in the whole growth period,photosynthetic rate of the top and middle leafs was significantly decreased. The above result would influenced the absorb ability、the compound ability of soluble sugar and protein, dry weight and seed cotton yield was decreased in the end. The result showed that the production of some reactive oxygen species and product（MDA） and would be significantly increased in salt stress, the MDA could was important idex of salt stress.2. The distribution of water and salt in soil were significantly influenced by irrigation method,water was seeped deeper in drip irrigation than in furrow irrigation,and salt was concentrated under 30 cm depth,with drip irrigation under mulch,the soil water evaporation was lower than furrow irrigation,and formed a desalted zone located at 0-30 cm depth and in 15 cm width centered emitter,NO3--N was focused in this zero; the distribution position of water 、root and NO3--N were not agree. The result showed that the saline of new plant soil saline farm on drip irrigation saline on was significantly decreased in the beginning stage of drip（1 and 2 year）,with drip irrigation continue, the drip washing of saline was declined, the saline ratio of upper soil（0-40cm） was decreased from 0.6 % to 0.3 %,this soil saline could ensure the cotton normal grow.3. The root of cotton was produced “the compensation effect” in medium saline soil by drip irrigation. The density of root of cotton was increased and the diameter of root was thinned under 30 cm depth soil,the result showed that the length and area of cotton root was increased in medium saline,the “the compensation effect” was offseted the effect of saline influence. But “the compensation effect” was very weak in top saline soil（the saline rate of soil was 0.6 %）.4. Accumulations and distributions of N,P and K in cotton plant were affected by soil salinity in drip irrigation. Accumulations of N,P and K in boll were markedly reduced by soil salinity,but there were no significant difference in leaf and stem among three treatments. With soil salinity increasing,content of Ca2+,Na+ and Cl-in cotton plant were increased. Ca²⁺,Na⁺ and Cl^- were mainly accumulated in leaf and stem,but there were very low in seed cotton.