Changes in carbon and nitrogen contents and greenhouse gas emissions during the vermicomposting of rice straw amended with Azolla

作者：Christian Nkurunziza, Jean Yves Dukuzumuremyi, Shuirong Tang, Margi Asih Maimunah, Samuel Munyaka Kimani, Shigeto Sudo, Keitaro Tawaraya, K. Horiguchi, Yupeng Wu, Weiguo Cheng · 发表于：Soil Science & Plant Nutrition · 年份：2025 · DOI：10.1080/00380768.2025.2490651 · 被引用次数：5 · 研究领域：Composting and Vermicomposting Techniques、Constructed Wetlands for Wastewater Treatment、Biological Control of Invasive Species

Rice straw (RS) composting, while time-consuming and associated with substantial greenhouse gas (GHG) emissions due to its high carbon (C) content, may be accelerated by the application of Azolla and earthworms, which stimulate the composting of agricultural residues. To outline this issue, an indoor box experiment was set up in a composting house for 12 weeks at Yamagata University, Tsuruoka, Japan in 2022, with and without applying Azolla and earthworms. Four treatments as ① RS only, ② RS with earthworm (RSE), ③ RS amended with Azolla (RSA, the ratio of RS and Azolla was 9:1), and ④ RSA with earthworm (RSAE) were set in the experiment. The total C (TC), total nitrogen (TN), δ13C, δ15N, and total phosphorus (TP) were measured after composting, while methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) fluxes were measured twice a week during the composting period. As a result, δ13C, δ15N, N2O, CH4, and CO2 significantly changed as affected by different input materials. The Azolla (RSAE and RSA) treatments recorded substantially higher total N2O and CH4 emissions (P < 0.001) but, significantly lower CO2 emissions than the non-Azolla (RS and RSE) treatments. Furthermore, Azolla treatments had higher TN and TP contents but lower TC contents than non-Azolla treatments. Compared with non-Azolla treatments, the Azolla treatments increased TN and TP contents by 69% and 29% for RSA and by 60% and 19% for RSAE, respectively. The higher TN and TP contents in both Azolla treatm...