Tillage and soil carbon sequestration—What do we really know? |
| |
| Institution: | 1. USDA-ARS, 454 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN 55108, USA;2. Department of Soil, Water & Climate, University of Minnesota, 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN 55108, USA;1. Campus Dois Vizinhos, Universidade Tecnológica Federal do Paraná, 85660-000 Dois Vizinhos-RS, PR, Brazil;2. Departamento de Solos e Engenharia Agrícola, Universidade Federal do Paraná, 80035-050 Curitiba, PR, Brazil;3. Departamento de Solos, Universidade Federal do Rio Grande do Sul, 90001-970 Porto Alegre, RS, Brazil;1. College of Agronomy and Biotechnology, China Agricultural University, Key Laboratory of Farming System, Ministry of Agriculture of China, Beijing 100193, China;2. Limpopo Department of Agriculture, Research Services (Cropping Systems Division), Polokwane 0699, South Africa;3. Carbon Management and Sequestration Center, School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio 43210, USA;1. Thuenen Institute of Climate-Smart Agriculture, Bundesallee 50, 38116 Braunschweig, Germany;2. Swedish University of Agricultural Sciences (SLU), Department of Ecology, Box 7044, 75007 Uppsala, Sweden;1. Dep. of Agronomy and Horticulture, Univ. of Nebraska-Lincoln, 1875 N. 38th Street, Lincoln, NE 68583, United States;2. Department of Biological Systems Engineering, University of Nebraska-Lincoln, NE 68583, United States;1. ICAR Research Complex for NEH Region, Tripura Centre, Tripura, India;2. Carbon Management and Sequestration Centre, The Ohio State University, Columbus, USA;3. Institute of Agricultural Sciences, Banaras Hindu University,Kabir Colony, Varanasi, Uttar Pradesh, 221005, India;4. ICAR Research Complex for NEH Region, Umiam, Meghalaya, India;5. College of Agriculture, Tripura University, Tripura, India;1. Universidad Pablo de Olavide, Ctra. de Utrera, km. 1, 41013 Sevilla, Spain;2. UPMC/CNRS, UMR Sisyphe, 4, Place Jussieu, 75005 Paris, France;3. Department of Ecology, Universidad Complutense de Madrid, c/José Antonio Novais, s/n, 28040 Madrid, Spain;4. Research Institute of Organic Agriculture, Ackerstrasse, CH-5070 Frick, Switzerland;5. Ecotoxicology of Air Pollution, CIEMAT, Avda. Complutense 22, 28040 Madrid, Spain |
| |
| Abstract: | It is widely believed that soil disturbance by tillage was a primary cause of the historical loss of soil organic carbon (SOC) in North America, and that substantial SOC sequestration can be accomplished by changing from conventional plowing to less intensive methods known as conservation tillage. This is based on experiments where changes in carbon storage have been estimated through soil sampling of tillage trials. However, sampling protocol may have biased the results. In essentially all cases where conservation tillage was found to sequester C, soils were only sampled to a depth of 30 cm or less, even though crop roots often extend much deeper. In the few studies where sampling extended deeper than 30 cm, conservation tillage has shown no consistent accrual of SOC, instead showing a difference in the distribution of SOC, with higher concentrations near the surface in conservation tillage and higher concentrations in deeper layers under conventional tillage. These contrasting results may be due to tillage-induced differences in thermal and physical conditions that affect root growth and distribution. Long-term, continuous gas exchange measurements have also been unable to detect C gain due to reduced tillage. Though there are other good reasons to use conservation tillage, evidence that it promotes C sequestration is not compelling. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
