| dc.contributor.author | Aher, Gabriel Garang | |
| dc.description.abstract | Carbon dioxide (CO2) and nitrous oxide (N2O) concentrations in the atmosphere have greatly increased in recent times. Intensive agricultural practices, combustion of fossil fuels, deforestation, and wetland drainage have been linked to increased greenhouse gases (GHG) levels. Although scientists are not unanimous in their belief that the increases in GHG is a cause behind recent global temperature rise, there is evidence that increases in GHG might directly increase global temperatures and unpredictable weather occurrences. Since human activity may be partially behind the rise in GHG emissions, it follows that changes in agricultural management might reduce the rate of GHG increases or even mitigate existing increases. Agricultural management practices proposed to mitigate GHG emissions in agricultural soils include conservation tillage, diversified cropping systems, and crop residue management. The objective of this study was to determine the impacts of high-residue no-till systems in a diverse rotation using seven cropping systems in which winter wheat (Triticum aestivum L.) was included or not included. The study was imposed on existing rotations present at the Conservation Cropping Systems Project (CCSP) farm near Forman, ND. The CCSP site was established in 2001 under no-till production and managed by the Wild Rice Soil Conservation District. Analysis of 2006 and 2010 soil organic carbon (SOC) data showed no significant difference between winter wheat rotation treatments and rotation treatments without winter wheat. Analysis of 2012 SOC data resulted in greater SOC in the corn (Zea mays L.)-soybean (Glycine max L.) rotation and lower SOC in the spring wheat (Triticum aestivum L.)-winter wheat (Triticum aestivum L.)-cover crop-soybean rotation. Some rotations had greater SOC than others, but the differences were not related to whether or not winter wheat was included in the rotations. Analysis of residue showed a greater C:N ratio and greater potential N requirement for the subsequent crop in fresh residue compared to aged residue. The COMET-VR model used to estimate SOC levels overestimated SOC in greater diversified rotations and underestimated SOC in lower diversified rotations. No-till production and crop residue retention can increase SOC levels, improve soil quality, and increase SOC sequestration in cropping systems. | en_US |
| dc.publisher | North Dakota State University | en_US |
| dc.rights | NDSU policy 190.6.2 | |
| dc.title | Winter Wheat Management for Improving Soil Quality and Reducing Greenhouse Gas Emissions | en_US |
| dc.type | Dissertation | en_US |
| dc.date.accessioned | 2017-12-19T20:51:14Z | |
| dc.date.available | 2017-12-19T20:51:14Z | |
| dc.date.issued | 2014 | |
| dc.identifier.uri | https://hdl.handle.net/10365/27092 | |
| dc.rights.uri | https://www.ndsu.edu/fileadmin/policy/190.pdf | |
| ndsu.degree | Doctor of Philosophy (PhD) | en_US |
| ndsu.college | Agriculture, Food Systems and Natural Resources | en_US |
| ndsu.department | Natural Resources Management | en_US |
| ndsu.department | School of Natural Resource Sciences | en_US |
| ndsu.program | Natural Resources Management | en_US |
| ndsu.advisor | Cihacek, Larry J. | |
