Conservation tillage increases carbon sequestration of winter wheat-summer maize farmland on Loess Plateau in China.

Xingli Lu,Xingneng Lu,Yuncheng Liao,Dafeng Hui

doi:10.1371/journal.pone.0199846

Abstract

The idea of mitigating anthropogenic CO2 emissions by increasing soil organic carbon (SOC) is notable. However, the estimation of the net ecosystem carbon balance after conversion from conventional tillage to conservational tillage has been poorly quantified for the Loess Plateau in China. A 2-year field experiment was conducted to estimate the agroecosystem carbon balance of a winter wheat–summer maize rotation system using a full carbon cycle analysis. The results showed that a positive net ecosystem carbon balance value in the cases of rotary tillage with straw incorporation, chisel plow tillage with straw incorporation, and no tillage with straw mulching treatments. Note that a negative value was detected for the conventional moldboard plowing tillage without crop straw treatment. The conversion from conventional tillage to conservational tillage substantially enhanced the carbon sink potential from 0.84 t C ha−1 yr−1 to 2.69 t C ha−1 yr−1 in both years. Our findings suggest that the expansion of conservational tillage could enhance the potential carbon sink of the rain-fed land in China.

Highlights

Agriculture accounts for approximately 10.0%–12.0% of the total global anthropogenic emissions of greenhouse gases (GHGs) [1]
No difference in the wheat yield was recorded among the different tillage treatments in 2013–14, while the STS significantly (p < 0.05) increased the maize yield by 19.5% as compared with crop straw (CT)
Xu et al [34] reported that when compared to conventional tillage, chisel plow could improve the yield of crops by loosening the soil and promoting the root growth of the crop

Summary

Introduction

Agriculture accounts for approximately 10.0%–12.0% of the total global anthropogenic emissions of greenhouse gases (GHGs) [1]. The winter wheat–summer maize rotation system under a rain-fed condition is one of the major grain productions in North China [3]. It is important to study carbon balance in rain-fed fields to select appropriate tillage methods to develop low-carbon agriculture and promote the development of sustainable agriculture. Previous studies have been conducted to evaluate the carbon source or sink by using several methods such as net carbon flux [4,5], net ecosystem productivity [6], and carbon sustainability [7]. Previous studies on the carbon balance were primarily focused on forest, grassland, and wetland ecosystems [8,9,10,11].

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