Biochar Application Alleviated Rice Salt Stress via Modifying Soil Properties and Regulating Soil Bacterial Abundance and Community Structure

Jing Huang,Lianfeng Zhu,Chunquan Zhu,Yongchun Zhang,Hui Zhang,Yijun Yu,Yunwang Ning,Junhua Zhang,Wenhao Tian,Yali Kong,Xiaochuang Cao

doi:10.3390/agronomy12020409

Abstract

Increased soil salinity significantly inhibits crop production worldwide, and biochar may alleviate salt stress. In the present study, the application of biochar significantly increased the biomass of rice under salt stress treatment. The analysis of soil properties demonstrated that biochar application significantly decreased electrical conductivity and soluble Na+ and Cl− contents in the soil under salt stress. In addition, biochar application increased the soil cation exchange capacity, soil organic matter, humic acid, total nitrogen, and total phosphorus contents in the soil, suggesting that biochar improved the soil nutrient conditions. The application of biochar further increased the abundance of soil bacteria and changed the bacterial community structure under salt stress. Proteobacteria, Chloroflexi, and Acidobacteria were the top three phyla in bacterial abundance. Biochar increased Proteobacteria abundance and decreased Chloroflexi abundance, which were considered to be eutrophic bacteria and oligotrophic bacteria, respectively. Redundancy analysis showed that soil bacterial communities were mainly affected by soil pH and EC (p < 0.05). In conclusion, the application of biochar alleviated salt stress in rice via modifying soil properties and regulating the bacterial abundance and community structure.

Highlights

According to the survey data of the Food and Agriculture Organization of the UnitedNations (FAO), as of 2017, about 7.6 million hm2 of cultivated land in China had saline–alkali soil, including 6.6 million hm2 of saline soil and 1.46 million hm2 of alkaline soil.Sodium salt is the main component in saline–alkali soil and one of the most dissolved salts
Biochar application dramatically reversed thedry inhibition ricethe growth growth induced by salt stress
The application of biochar significantly decreased the value of electrical conductivity (EC), soluble Na+ and Cl− contents, and increased cation exchange capacity (CEC), Soil organic matter (SOM), Humic acid (HA), total nitrogen, and total phosphorus contents in the soil

Summary

Introduction

According to the survey data of the Food and Agriculture Organization of the UnitedNations (FAO), as of 2017, about 7.6 million hm of cultivated land in China had saline–alkali soil, including 6.6 million hm of saline soil and 1.46 million hm of alkaline soil.Sodium salt is the main component in saline–alkali soil and one of the most dissolved salts. According to the survey data of the Food and Agriculture Organization of the United. Alkali soil, including 6.6 million hm of saline soil and 1.46 million hm of alkaline soil. Sodium salt is the main component in saline–alkali soil and one of the most dissolved salts. The accumulation of sodium salt in the soil causes ion imbalance, osmotic stress, and metabolic disorders in plants, in addition to affecting normal physiological processes [1]. Rice (Oryza sativa L.) is a moderately salt-sensitive crop, and soil salinization significantly restricts rice yield and quality. It is estimated that about one-fifth of paddy soils in China are under salt stress.

Methods

Results

Discussion

Conclusion