Crop – Livestock integration via maize straw recycling increased carbon sequestration and crop production in China

• Published in: Agricultural systems 2023-08, Vol.210, p.103722, Article 103722
• Main Authors: Liu, Ling, Zheng, Hui-fang, Liu, Zhen, Ma, Yu-Zhao, Han, Hui-fang, Ning, Tang-yuan
• Format: Article
• Language: English
• Subjects: Carbon sequestration; Crop-livestock system; Organic waste
• ISSN: 0308-521X; 1873-2267
• DOI: 10.1016/j.agsy.2023.103722

Agriculture production is crucial in mitigating climate change while securing food productivity. However, the impact of the practices such as organic waste (crop residue and animal manure) recycling or integrating crop-livestock system on productivity and carbon sequestration was unclear. This study presents a potential crop-livestock model to enhance carbon sequestration from a whole system perspective. This study aimed to (i) examine the effect of different organic waste recycling on contents of SOC, MBC, and EOC at a depth of 0–60 cm of soil; (ii) analyze the sequestration potential of SOC for different organic wastes recycling models using the substance flow balance method; and (iii) propose suitable organic wastes recycling models for crop and livestock production system in China from the whole-system perspective. This study conducted a comparative assessment of carbon sequestration of diverse organic wastes in China using a four-year field experiment and substance flow balance method. The field experiment involved three types of organic waste (raw maize straw (MS), biogas slurry (BS), dairy manure (DM)) and two fertilizer application treatments (unfertilized control (CK), and only chemical fertilizer (CF)). Based on the field results, the carbon flow for different organic waste recycle models was compared using the substance flow approach. The content and sequestration of SOC and its fractions increased with the application of organic wastes. The effect of organic wastes on SOC sequestration followed the order DM > MS > BS. Additionally, organic waste, especially DM, significantly increased the sequestration of MBC and EOC by 198% and 359%, respectively, compared to CF. The SOC, MBC, and EOC sequestration rates for DM treatment were 2.9–3.2, 0.3–0.6, and 2.7–3.0 Mg ha−1 yr−1, respectively. On a per-crop yield basis, the “crop straw-livestock-manure-field” model contributed about six times more for SOC sequestration than CF. Future estimation showed that the DM model could reduce chemical fertilizer use by 36% compared to CF, resulting in lower costs. Therefore, the “crop straw-livestock-manure-field” system benefits carbon sequestration and emphasizes the importance of expanding the organic waste management chain. The findings have significant implications for the agricultural system, highlighting the importance of integrating the “crop straw-livestock-manure-field” model for carbon sequestration and sustained productivity. The results demonstrate th