Predicting soil organic matter stability in agricultural fields through carbon and nitrogen stable isotopes |
| |
| Institution: | 1. Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium;2. Soil and Water Management & Crop Nutrition Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria;3. Department of Resources and Environmental Sciences, Fujian Agriculture and Forestry University, Fujian, China;4. Soil Service of Belgium, Willem de Croylaan 48, BE-3001 Leuven, Belgium;5. Isotope Research and Nuclear Physics, VERA Laboratory, University of Vienna, Vienna, Austria;6. Climate/Air Pollution Group, Agroscope, Institute for Sustainability Sciences ISS, Zürich, Switzerland;1. Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA;2. Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria;3. Department of Soil Ecology, University of Bayreuth, Bayreuth, Germany;4. Department of Forest Ecology, Federal Research and Training Centre for Forests, Natural Hazards and Landscape – BFW, Vienna, Austria;1. Department of Microbiology & Plant Biology, University of Oklahoma, Norman, OK, USA;2. Key Laboratory of Soil and Water Conservation and Ecological Restoration in Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing, China;3. School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China;1. Department of Soil Science and Land Management, Federal University of Agriculture, P.M.B 2240, Abeokuta, Nigeria;2. The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera, 11, 1-34151 Trieste, Italy;1. State Engineering Laboratory of Efficient Water Use of Crops and Disaster Loss Mitigation/Key Laboratory of Dryland Agriculture, Ministry of Agriculture and Rural Affairs, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China;2. National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China;3. University de Liège, GxABT, Terra Research Center, 2 Passage des Déportés, 5030, Gembloux, Belgium |
| |
| Abstract: | In order to evaluate the sustainability and efficiency of soil carbon sequestration measures and the impact of different management and environmental factors, information on soil organic matter (SOM) stability and mean residence time (MRT) is required. However, this information on SOM stability and MRT is expensive to determine via radiocarbon dating, precluding a wide spread use of stability measurements in soil science. In this paper, we test an alternative method, first developed by Conen et al. (2008) for undisturbed Alpine grassland systems, using C and N stable isotope ratios in more frequently disturbed agricultural soils. Since only information on carbon and nitrogen concentrations and their stable isotope ratios is required, it is possible to estimate the SOM stability at greatly reduced costs compared to radiocarbon dating. Using four different experimental sites located in various climates and soil types, this research proved the effectiveness of using the C/N ratio and δ15N signature to determine the stability of mOM (mineral associated organic matter) relative to POM (particulate organic matter) in an intensively managed agro-ecological setting. Combining this approach with δ13C measurements allowed discriminating between different management (grassland vs cropland) and land use (till vs no till) systems. With increasing depth the stability of mOM relative to POM increases, but less so under tillage compared to no-till practises. Applying this approach to investigate SOM stability in different soil aggregate fractions, it corroborates the aggregate hierarchy theory as proposed by Six et al. (2004) and Segoli et al. (2013). The organic matter in the occluded micro-aggregate and silt & clay fractions is less degraded than the SOM in the free micro-aggregate and silt & clay fractions. The stable isotope approach can be particularly useful for soils with a history of burning and thus containing old charcoal particles, preventing the use of 14C to determine the SOM stability. |
| |
| Keywords: | Soil organic matter Stability Stable isotopes Aggregate fractions Depth effect |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
