The Crop Residue Removal Threshold Ensures Sustainable Agriculture in the Purple Soil Region of Sichuan, China

Peng Zhang,Yuxin He,Tao Ren,Chao Liu,Yang Wang,Naiwen Li,Longguo Li

doi:10.3390/su13073799

Abstract

Sichuan, a hilly area in southwestern China, is recommended as a bioethanol production base because of its abundant crop residue resources. However, removing the crop straw for bioethanol may negatively affect soil fertility and productivity due to the local purple soil vulnerability. To explore the impact of crop residue removal on soil fertility and productivity and meet the needs of sustainable agriculture, we conducted a crop residue removal experiment by measuring the soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents, and crop yield in the purple soil region in southwest China. Soil erosion was also simulated by Revised Universal Soil Loss Equation version 2 (RUSLE 2). The results showed that soil erosion increased with the increase of the straw removal rate. Compared with 0% removal treatment, the SOC content reduced at other removal rate treatments, especially for long-term residue removal. The effect of residue removal on soil TN and TP was not consistent within one year. After two years, residue removal greater than 25% caused a decrease in TN by 1.6–3.7%, and straw removal greater than 50% caused a TP decrease by 8.5–9.3%. More than 25% of the residue removed reduced maize and canola yields, and TN and TP content. However, all crop residue removal treatments resulted in SOC content reduction and soil erosion deterioration. In conclusion, crop residue removal was not recommended due to agricultural sustainability in Sichuan, China.

Highlights

The Sichuan Basin, with its rich biodiversity and complex landscapes in southwesternChina, is the main agricultural production region in the upper reaches of the YangtzeRiver [1]
The results showed that the crop residue removal rate, duration, and interaction significantly (p < 0.05) affected the soil organic carbon (SOC)
High straw removal rate would significantly decrease the SOC content, and the decrease in the SOC content became more evident as the experiment time increases

Summary

Introduction

The Sichuan Basin, with its rich biodiversity and complex landscapes in southwesternChina, is the main agricultural production region in the upper reaches of the YangtzeRiver [1]. The Sichuan Basin, with its rich biodiversity and complex landscapes in southwestern. China, is the main agricultural production region in the upper reaches of the Yangtze. The primary soil type in this region is purple soil, which is often neutral or alkaline [2]; rich in mineral nutrients [3]; and prone to weathering, erosion, and leaching [4]. Ignoring the effect of residue removal on soil physical and chemical properties may not suitable for sustainable agriculture [7]. Making full use of residue resources is essentially in line with sustainable agriculture requirements, there are more aspects to consider, such as soil erosion control, fertility loss, and productivity deteriorating

Objectives

Methods

Results

Conclusion