Effect of Salinity on the Transformation of Wheat Straw and Microbial Communities in a Saline Soil

Abstract

Currently, straw transformation in saline soil is largely unknown. The effect of soil salinity on wheat straw transformation and the roles of nitrogen (N) and phosphorus (P) were evaluated in a greenhouse experiment. By sodium chloride (NaCl) addition, straw was applied at the rate of 30 g kg−1 in various saline soils (2.0–4.0 g kg−1). N or combined N and P added in straw amended saline soil (3.0 g kg−1). Three replications of each treatment were sampled to determine straw residues at 30, 60, and 90 d. Results showed straw application significantly increased microbial biomass, especially fungal biomass. Soil salinity increased by 1.0 g kg−1, which decreased straw decomposed rate by 6.3 ~ 11.1%. N application significantly increased straw decomposed rate (p < 0.05), and high salinity obviously inhibited the humidification process of straw. We suggested that straw carbon transformation regulation and little straw residue accumulation in saline soil should arouse more attentions in future studies.