Pedosphere 30(5): 661--670, 2020
ISSN 1002-0160/CN 32-1315/P
©2020 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Co-incorporation of rice straw and leguminous green manure can increase soil available nitrogen (N) and reduce carbon and N losses: An incubation study |
Guopeng ZHOU1,2, Weidong CAO1,3 , Jinshun BAI1, Changxu XU4, Naohua ZENG1, Songjuan GAO1,2, Robert M. REES5, Fugen DOU6 |
1Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing100081 (China)
2Graduate School, Chinese Academy of Agricultural Sciences, Beijing 100081 (China)
3Soil and Fertilizer Institute, Qinghai Academy of Agriculture and Forestry Sciences, Qinghai University, Xining 810016 (China)
4Institute of Soil & Fertilizer and Resource & Environment, Jiangxi Academy of Agricultural Sciences, Nanchang 330200 (China)
5Scotland's Rural College (SRUC), Edinburgh EH9 3JG (UK)
6Texas A & M AgriLife Research Center at Beaumont, Texas 77713 (USA) |
| ABSTRACT |
| Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China. Despite the popularity of this practice, our understanding of the underlying processes for straw and manure combined application is relatively poor. In this study, rice straw (carbon (C)/nitrogen (N) ratio of 63), green manure (hairy vetch, C/N ratio of 14), and their mixtures (C/N ratio of 25 and 35) were added into a paddy soil, and their effects on soil N availability and C or N loss under waterlogged conditions were evaluated in a 100-d incubation experiment. All plant residue treatments significantly enhanced CO2 and CH4 emissions, but decreased N2O emission. Dissolved organic C (DOC) and N (DON) and microbial biomass C in soil and water-soluble organic C and N and mineral N in the upper aqueous layer above soil were also enhanced by all the plant residue treatments except the rice straw treatment, and soil microbial biomass N and mineral N were lower in the rice straw treatment than in the other treatments. Changes in plant residue C/N ratio, DOC/DON ratio, and cellulose content significantly affected greenhouse gas emissions and active C and N concentrations in soil. Additionally, the treatment with green manure alone yielded the largest C and N losses, and incorporation of the plant residue mixture with a C/N ratio of 35 caused the largest net global warming potential (nGWP) among the amended treatments. In conclusion, the co-incorporation of rice straw and green manure can alleviate the limitation resulting from only applying rice straw (N immobilization) or the sole application of leguminous green manure (high C and N losses), and the residue mixture with a C/N ratio of 25 is a better option because of lower nGWP. |
| Key Words: active C and N pools,C/N ratio,global warming potential,greenhouse gas,plant residues,straw returning |
| Citation: Zhou G P, Cao W D, Bai J S, Xu C X, Zeng N H, Gao S J, Rees R M, Dou F G. 2020. Co-incorporation of rice straw and leguminous green manure can increase soil available nitrogen (N) and reduce carbon and N losses:An incubation study. Pedosphere. 30(5):661-670. |
| |
|
View Full Text
|
|
|
|
