Dynamics of Soil Organic Carbon and Labile Carbon Fractions in Soil Aggregates Affected by Different Tillage Managements

Xiaolin Shen,Gang Li,Weiming Xiu,Lili Wang,Qichen Yang,Guilong Zhang,Jianning Zhao

doi:10.3390/su13031541

Abstract

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.

Highlights

IntroductionSoil organic carbon (SOC) is one of the most widely used indicators of soil fertility
Soil organic carbon (SOC) is one of the most widely used indicators of soil fertility.SOC affects soil physical, chemical, and biological characteristics, regulating soil quality and ecosystem function [1]
Soil aggregate distribution was influenced by tillage effects (Figure 1)

Summary

Introduction

Soil organic carbon (SOC) is one of the most widely used indicators of soil fertility. SOC affects soil physical, chemical, and biological characteristics, regulating soil quality and ecosystem function [1]. Agricultural soils, as strongly affected by human activities, are important parts of terrestrial SOC pools [3]. Increasing soil organic carbon pools through appropriate agricultural measures is of great significance, in agricultural production, and in the sustainable development of ecological environment. SOC stocks are not sensitive to changes in agricultural soil management due to the complexity and stability of its multiple compounds. The labile pools of SOC are usually measured to evaluate the rapid change of soil quality [1]

Objectives

Results

Discussion

Conclusion