Effects Of Biodegradable Liquid Mulch On Saline Ground Vegetation And Soil Environment

Saline land has an important impact on ecological environment and agricultural production,etc.China is a large country with saline land,and saline land is characterized by large area and wide distribution,etc.The management and improvement of saline land is of great significance to protect the ecological environment and arable land safety in China.In this study,a lightly saline soil in Jinghai County,Tianjin was used as the research sample site to study the effect of liquid mulch on the vegetation and soil environment of saline soil.Five different concentration gradients:CK,Y0.5,Y1,Y1.5,Y3(0 kg·hm^-2,187.5 kg·hm^-2,375 kg·hm^-2,562.5kg·hm^-2,1125 kg·hm^-2)were applied as different liquid mulch spraying treatments in the study plots to study the effects on aboveground plant community,belowground soil physicochemical and microbial community structure and diversity.The effects on above-ground plant community,below-ground soil physicochemical and microbial community structure and diversity were investigated.The research results can provide new ideas for saline land management and provide data support and theoretical basis for the improvement of saline soils by biodegradable liquid mulch.The main research results are as follows:（1）Liquid mulch spraying significantly increased above-ground biomass and community diversity.The best increase in above-ground biomass was achieved at 562.5kg·hm^-2,with more than 50%increase compared to the control.The community diversity was significantly increased at the high liquid mulch application rate(1125kg·hm^-2).（2）Spraying liquid mulch can significantly affect the soluble salt ions of saline soils,especially soluble cations and bicarbonate ions（HCO₃^-）and carbonate ions(CO₃^2-).It was found that the spraying conditions at low concentration(187.5 kg·hm^-2)had a more significant tendency to reduce soluble cations and HCO₃^-and CO₃^2-in saline soils.（3）Liquid mulch sprayed at 562.5 kg·hm^-2 had a significantly higher effect on soil organic carbon and soil total nitrogen than the other treatments;liquid mulch concentrations higher than or equal to the standard on-farm spraying concentration(375kg·hm^-2)promoted the accumulation of soil total nitrogen,with the most pronounced effect under the 375 kg·hm^-2 treatment;while liquid mulch at different concentrations promoted the accumulation of soil effective phosphorus at all The effect of liquid mulch at different concentrations on soil effective phosphorus accumulation was the most obvious.（4）The spraying of liquid mulch had a significant effect on the microbial community structure of saline soils.The results showed that the effect of spraying liquid mulch on the diversity of soil bacterial communities in saline soils was significant,and the bacterial diversity was higher at the standard spraying concentration of 375 kg·hm^-2,but the effect on the bacterial community structure did not reach a significant level.In contrast,the diversity and abundance of soil fungal communities increased significantly with the increase of liquid mulch spraying,and the structural diversity of fungal communities was higher at the spraying concentration of 562.5 kg·hm^-2.This study shows that biodegradable liquid mulch has an ameliorating effect on saline soils.It improved the above-ground biomass and diversity of saline land,reduced soil soluble salt ions,increased soil organic carbon and soil microbial diversity,and provided a theoretical basis and data support for further saline land restoration and improvement measures.