Soil Enzyme Activity and Microbial Metabolic Function Diversity in Soda Saline–Alkali Rice Paddy Fields of Northeast China

Sining Wang,Zihao Zhou,Zhaoyang Li,Yidan Cao,Jie Tang,Jingjing Wang,Yunke Qu

doi:10.3390/su122310095

Abstract

Western Jilin province has the most serious area of soda salinization in Northeast China, which affects and restricts the sustainable development of agriculture. The effects of physico-chemical properties of rhizosphere and non-rhizosphere soil on soil microbial diversity and enzyme activities (polyphenol oxidase, catalase, invertase, amylase) were evaluated in typical soda saline-alkali paddy field. Community-level physiological profile (CLPP) based on Biolog-ECO plates was used to assess the functional diversity of soil microorganisms. Exchangeable sodium percentage (ESP) and pH were negative correlated with the microbial activity (AWCD), soil enzyme activities (amylase, sucrose, and catalase, except for polyphenol oxidase) in rice rhizosphere and non-rhizosphere soil (P < 0.05). The indexes of microbial diversity in rice rhizosphere soil were significantly higher than that of non-rhizosphere soil. The utilization of amino acids by rice rhizosphere microorganisms was relatively high, while non-rhizosphere soil had relatively high utilization of carboxylic acid, phenolic acid, and amine. Among the selected physico-chemical properties, soil organic carbon (SOC) and soil water content (SWC) had the greatest influence on the variation of microbial diversity indexes and enzyme activities in rhizosphere soil. ESP and pH showed a significant positive correlation with carbon source utilization, especially for amine (AM) and phenolic acid (PA) carbon source utilization (P < 0.05) by means of RDA, and the utilization rate of AM and PA carbon sources by rice rhizosphere and non-root soil microorganisms was P1 < P2 < P3.

Highlights

Songnen Plain, an important grain-producing area in China, is one of the three major concentrated distribution areas of soda saline-alkali soil in the world [1]
The content of soil organic carbon (SOC) decreased with the increase of soil pH and Exchangeable sodium percentage (ESP)
The effects of different physical-chemical properties of rhizosphere and non-rhizosphere on soil enzyme activity and utilization of carbon source of saline-alkali paddy fields (P1, P2, P3) in Northeast China were evaluated by field sampling and laboratory experiments, the following conclusions were drawn: (1) Saline-alkali soil affected soil microbial diversity by affecting the physical-chemical properties of rice rhizosphere and non-rhizosphere soil

Summary

Introduction

Songnen Plain, an important grain-producing area in China, is one of the three major concentrated distribution areas of soda saline-alkali soil in the world [1]. It lies in the central part of Northeast China, which is a typical vulnerable area for global carbon cycle research [2,3]. Soil salinization will harm the normal growth of plants, changes the structure and function of the cell membrane, and produces toxic effects on cells. Effective measures should be taken to reduce soil salinization [11]

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