Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA)
The transition of natural landscapes to agricultural uses has resulted in severe loss of soil organic carbon, significantly contributing to CO<sub>2</sub> emissions and rising global temperatures. However, soil has the largest store of terrestrial carbon (C), a considerable sink and effe...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Environments |
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| Online Access: | https://www.mdpi.com/2076-3298/9/9/109 |
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| author | Alexandra G. Firth John P. Brooks Martin A. Locke Dana J. Morin Ashli Brown Beth H. Baker |
| author_facet | Alexandra G. Firth John P. Brooks Martin A. Locke Dana J. Morin Ashli Brown Beth H. Baker |
| author_sort | Alexandra G. Firth |
| collection | DOAJ |
| description | The transition of natural landscapes to agricultural uses has resulted in severe loss of soil organic carbon, significantly contributing to CO<sub>2</sub> emissions and rising global temperatures. However, soil has the largest store of terrestrial carbon (C), a considerable sink and effective strategy for climate change mitigation if managed properly. Cover crops (CC) and no-till (NT) management are two management strategies that are known to increase percent organic carbon (%OC); however, adoption of these practices has been low in the mid-South due to lack of region-specific research and resistance to unproven practices. Therefore, the purpose of this study was to evaluate the impacts of CC-NT treatments in soybean cropping systems on soil percent organic carbon (%OC) and CO<sub>2</sub> flux following long-term implementation. Results showed significantly greater %OC in NT (1.27% ± 0.03) than reduced till (RT; 1.10% ± 0.03; <i>p</i> < 0.001) and greater in both CC (rye: 1.23% ± 0.03, rye + clover: 1.22% ± 0.03) than no cover (1.11% ± 0.03; <i>p</i> < 0.001). Bacterial abundance (<i>p</i> = 0.005) and pH (<i>p</i> = 0.006) were significant predictors of %OC. There was no overall significant difference in CO<sub>2</sub> flux between tillage or CC treatments; however, there were significant differences between NT and RT in July of 2020 when %RH increased (<i>p</i> < 0.001). Bacterial abundance negatively impacted CO<sub>2</sub> flux (<i>p</i> < 0.05), which contradicts most studies. The rate of proportional change and pattern of variability in C pools suggested loss of %OC in RT treatments that were not apparent when considering %OC alone. The results of this study provide valuable insight into C turnover and the effectiveness of CC use in the Mid-South to increase soil C stocks. |
| first_indexed | 2024-03-10T00:05:14Z |
| format | Article |
| id | doaj.art-5bdadf1ca491492bb4832c4ca21dbab2 |
| institution | Directory Open Access Journal |
| issn | 2076-3298 |
| language | English |
| last_indexed | 2024-03-10T00:05:14Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Environments |
| spelling | doaj.art-5bdadf1ca491492bb4832c4ca21dbab22023-11-23T16:09:44ZengMDPI AGEnvironments2076-32982022-08-019910910.3390/environments9090109Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA)Alexandra G. Firth0John P. Brooks1Martin A. Locke2Dana J. Morin3Ashli Brown4Beth H. Baker5Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mississippi State, MS 39762, USAUSDA-ARS, Genetics and Sustainable Agriculture Research Unit, Mississippi State, MS 39762, USAUSDA-ARS, National Sedimentation Laboratory, Oxford, MS 38655, USADepartment of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mississippi State, MS 39762, USADepartment of Biochemistry, Molecular Biology Entomology and Plant Pathology, Mississippi State, MS 39762, USADepartment of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mississippi State, MS 39762, USAThe transition of natural landscapes to agricultural uses has resulted in severe loss of soil organic carbon, significantly contributing to CO<sub>2</sub> emissions and rising global temperatures. However, soil has the largest store of terrestrial carbon (C), a considerable sink and effective strategy for climate change mitigation if managed properly. Cover crops (CC) and no-till (NT) management are two management strategies that are known to increase percent organic carbon (%OC); however, adoption of these practices has been low in the mid-South due to lack of region-specific research and resistance to unproven practices. Therefore, the purpose of this study was to evaluate the impacts of CC-NT treatments in soybean cropping systems on soil percent organic carbon (%OC) and CO<sub>2</sub> flux following long-term implementation. Results showed significantly greater %OC in NT (1.27% ± 0.03) than reduced till (RT; 1.10% ± 0.03; <i>p</i> < 0.001) and greater in both CC (rye: 1.23% ± 0.03, rye + clover: 1.22% ± 0.03) than no cover (1.11% ± 0.03; <i>p</i> < 0.001). Bacterial abundance (<i>p</i> = 0.005) and pH (<i>p</i> = 0.006) were significant predictors of %OC. There was no overall significant difference in CO<sub>2</sub> flux between tillage or CC treatments; however, there were significant differences between NT and RT in July of 2020 when %RH increased (<i>p</i> < 0.001). Bacterial abundance negatively impacted CO<sub>2</sub> flux (<i>p</i> < 0.05), which contradicts most studies. The rate of proportional change and pattern of variability in C pools suggested loss of %OC in RT treatments that were not apparent when considering %OC alone. The results of this study provide valuable insight into C turnover and the effectiveness of CC use in the Mid-South to increase soil C stocks.https://www.mdpi.com/2076-3298/9/9/109carbonno-tillcover cropssoil carbon sequestrationconservation agriculturecarbon measurement |
| spellingShingle | Alexandra G. Firth John P. Brooks Martin A. Locke Dana J. Morin Ashli Brown Beth H. Baker Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) Environments carbon no-till cover crops soil carbon sequestration conservation agriculture carbon measurement |
| title | Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) |
| title_full | Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) |
| title_fullStr | Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) |
| title_full_unstemmed | Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) |
| title_short | Dynamics of Soil Organic Carbon and CO<sub>2</sub> Flux under Cover Crop and No-Till Management in Soybean Cropping Systems of the Mid-South (USA) |
| title_sort | dynamics of soil organic carbon and co sub 2 sub flux under cover crop and no till management in soybean cropping systems of the mid south usa |
| topic | carbon no-till cover crops soil carbon sequestration conservation agriculture carbon measurement |
| url | https://www.mdpi.com/2076-3298/9/9/109 |
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