生物炭对中重度盐胁迫下棉花苗期根系形态及根系分泌物的影响OA北大核心

To reveal the regulatory effect of biochar on cotton seedling root growth and root exudates under moderate to severe salt stress,pot experiments were conducted by adding concentrations of 0(control),0.5%,1%,and 2%biochar and phosphoric acid-modified biochar to moderate and severe saline alkali soils,respectively,and the total root length,root surface area,root volume,and amounts of root exudates such as methane acid,acetic acid,and oxalic acid were measured during the seedling-stage of cotton.The results indicated that the increase in soil salinity significantly inhibited the total root length,root surface area,and root volume of cotton roots of the seedling stage.Under moderate and severe salt stress conditions,compared with the control,the total root length of cotton treated with 2%biochar and phosphoric acid-modified biochar significantly increased by 55.92%and 43.69%,respectively,and the root volume significantly increased by 41.73%and 55.88%,while the total root length of cotton treated with 0.5%biochar decreased by 25.31%.The use of unmodified biochar mainly increased the root methane acid content in cotton roots at seedling stage,while phosphoric acid-modified biochar significantly increased the content of oxalic acid,methane acid and citric acid in roots.Soluble total sugars showed a significant positive correlation with soil pH and soil total salt content.The content of methane acid in the cotton root was significantly negatively correlated with soil pH.The contents of oxalic acid,methane acid,and citric acid were significantly positively correlated with cotton root growth indicators(P<0.05).It can be concluded from the results that the recommended application of 2%phosphoric acid-modified biochar in moderately or severely saline soil is better than unmodified biochar in improving cotton root growth and salt tolerance physiological characteristics.