Agriculture, Ecosystems & Environment ( IF 6.0 ) Pub Date : 2022-01-13 , DOI: 10.1016/j.agee.2022.107865 Wanmao Liu 1, 2 , Yuee Liu 3 , Guangzhou Liu 1 , Ruizhi Xie 1 , Bo Ming 1 , Yunshan Yang 4 , Xiaoxia Guo 4 , Keru Wang 1 , Jun Xue 1 , Yonghong Wang 5 , Rulang Zhao 5 , Wenjie Zhang 5 , Yongjun Wang 6 , Shaofeng Bian 6 , Hong Ren 7 , Xiaoyan Zhao 7 , Peng Liu 8 , Jianzhi Chang 9 , Guohe Zhang 9 , Jiayou Liu 10
Accurate estimation of maize (Zea mays L.) straw production and exploration of appropriate straw return rate have important reference for guiding the comprehensive utilization of crop straw. In this study, we estimated the maize straw production (including aboveground straw and root straw) in recent ten years (2009–2018) of the four largest maize growing regions across China using the latest obtained region-specific maize straw index and root-shoot ratio and then determined the appropriate straw return rate of different regions based on the carbon (C) balance between straw C input and the total C emissions generated in maize cultivation. Our results showed that there were significant differences in maize straw index (MSI) and root-shoot ratio between different maize growing regions in China with spatial distribution trends of Huanghuaihai (HM) > North (NM) > Southwest (SW) > Northwest (NW) maize regions and SW > NW > NM > HM, respectively. On average, in the recent ten years, the total maize straw production of the four major regions was 216.03 Mt yr−1, including 192.73 Mt yr−1 for the aboveground straw production and 23.30 Mt yr−1 for root straw production. Nationally, when the maize straw return rate was 70.4% (45.8%, 57.4%, 62.2% and 84.5% in SW, HM, NW and NM respectively), the straw C input into soil can theoretically counterbalance the total C emission generated in maize cultivation. Additionally, the total soil organic C sequestration increased from 11.26 to 18.88 Mt C yr−1 for the whole four regions under the scenarios of 0%, 25%, 50%, 75% and 100% maize straw return.