Improvement of nitrogen and phosphorus availability by Pseudoalteromonas sp. during salt-washing in saline-alkali soil

Abstract

In saline-alkali soils, the inactivation of phosphorus and loss of nitrogen resulting in soil infertility could be intensified by salt, which simultaneously leads to pollution of water sphere. However, there is no complete solution for this challenge due to the weak nutrients biological turnover caused by salt dynamic accumulation. In this study, halophilic marine bacteria strains with carriers were screened to decrease the leaching of nitrogen and phosphorus inactivation in saline-alkali soil during salt-washing. Results showed the combination of Pseudoalteromonas sp. CF8-6 and corn cob significantly increased not only soil available phosphorus by 37.03%, but also the soil bioavailable phosphorus content. Moreover, the concentration of TN, NO3−, TP and PO43− in salt washing eluents reduced by corn cob colonized with CF8-6 significantly. It was also found that the abundance of nitrogen-fixing bacteria (such as Azotobacter), and abundance of Proteobacteria and Actinobacteria in soil were all increased by this combination, which were corresponding for the turnover of nitrogen and phosphorus. We demonstrated that the combination of CF8-6 and corn cob has promising potential in improvement of bioavailability of soil nitrogen and phosphorus during the salt-washing process in saline-alkali soil.