We studied the influence of different organic residues and water levels on decomposition rate and carbon sequestration in soil. Organic residues (rice straw, rice root, cow dung, and poultry litter) including control were tested under moistened and flooding systems. An experiment was laid out as a complete randomized design at 25°C for 120 days. Higher CO2-C (265.45 mg) emission was observed in moistened condition than in flooding condition from 7 to 120 days. Among the organic residues, poultry litter produced the highest CO2-C emission. Poultry litter with soil mixture increased 121% cumulative CO2-C compared to control. On average, about 38% of added poultry litter C was mineralized to CO2-C. Maximum CO2-C was found in 7 days after incubation and thereafter CO2-C emission was decreased with the increase of time. Control produced the lowest CO2-C (158.23 mg). Poultry litter produced maximum cumulative CO2-C (349.91 mg). Maximum organic carbon was obtained in cow dung which followed by other organic residues. Organic residues along with flooding condition decreased cumulative CO2-C, k value and increased organic C in soil. Maximum k value was found in poultry litter and control. Incorpored rice straw increased organic carbon and decreased k value (0.003 g d−1) in soil. In conclusion, rice straw and poultry litter were suitable for improving soil carbon.
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机译：我们研究了不同有机残留物和水位对土壤分解速率和固碳的影响。在潮湿和水浸系统下测试了有机残留物（稻草，稻根，牛粪和家禽垃圾），包括对照。在25°C下进行了120天的完整随机设计实验。在潮湿状态下观察到的CO2-C（265.45 mg）排放量比在淹没状态下高了7至120天。在有机残留物中，家禽垃圾产生的CO2-C排放最高。与对照相比，带有土壤混合物的家禽垫料累积的CO2-C增加121％。平均而言，添加的家禽垫料C中约有38％矿化为CO2-C。孵育后7天发现最大的CO2-C，此后随着时间的增加，CO2-C的排放量减少。对照产生最低的CO2-C（158.23mg）。家禽垫料产生的最大累积CO2-C（349.91 mg）。在牛粪中获得最大的有机碳，其次是其他有机残留物。有机物残留与洪水条件一起降低了土壤中的累积CO2-C，k值并增加了有机碳。在家禽垫料和对照中发现最大k值。秸秆还田增加了土壤有机碳，降低了土壤k值（0.003 g d -1 ）。总之，稻草和家禽垫料适合改善土壤碳含量。
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