Microbial mechanisms of cotton straw return to regulate soil N cycling in saline water drip irrigation cotton fields in arid zones

Summary

Long-term saline irrigation exacerbates soil salinity , inhibits nitrogen cycling efficiency, and threatens crop yield. Straw returning can mitigate these adverse effects, but the mechanism is unclear. This study conducted field experiments and set up treatments fresh water (FWCK), fresh water with straw (FWST), saline water (SWCK), and saline water with straw (SWST) to elucidate the driving mechanism of straw returning to the field on microbial nitrogen cycling. The results showed that whether straw is returned to the field or not, compared to fresh water irrigation, saline water irrigation increased soil salinity and water content, decreased NO 3 − -N and NH 4 + -N content, potential nitrification rate, cotton nitrogen uptake , and yield. Returning straw to the field (SWST vs SWCK) incre