Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release
Empirical models could help us to understand the process of plant residue decomposition and nutrient release into the soil. The objective of this study was to determine an appropriate model to describe the decomposition of hairy vetch (<i>Vicia villosa</i> Roth) and cereal rye (<i>...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-05-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/10/5/701 |
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| author | Madhav Dhakal Gurbir Singh Rachel L. Cook Taylor Sievers |
| author_facet | Madhav Dhakal Gurbir Singh Rachel L. Cook Taylor Sievers |
| author_sort | Madhav Dhakal |
| collection | DOAJ |
| description | Empirical models could help us to understand the process of plant residue decomposition and nutrient release into the soil. The objective of this study was to determine an appropriate model to describe the decomposition of hairy vetch (<i>Vicia villosa</i> Roth) and cereal rye (<i>Secale cereale</i> L.) cover crop (CC) residue and nitrogen (N) release. Data pertaining to above and belowground CC residue mass loss and N release for up to 2633 cumulative decomposition degree days (112 d) after litterbag installation were obtained from two cropping system experiments, a 1-yr study conducted in 2015 and a 2-yr study during 2017 to 2018 in the humid subtropical environment of southern IL, USA. Six exponential and two hyperbolic models were fit to percent mass and N remaining data to find the one with minimum Akaike information criterion (AIC) and residual sum of squares. Modified three-parameter single exponential and two- or three-parameter hyperbolic models best met the assumed criteria of selection for above and belowground CC residue, respectively. Fitting a double exponential model to combined data for percent mass and N remaining identified two mass and N pools, a fast and a slow pool with different rate constants. A five-parameter double exponential with an asymptote met the preset criteria and passed all tests for normally distributed population, constant variance, and independence of residuals at α = 0.05 when fit to combined data of hairy vetch shoot mass and N remaining. However, a two-parameter hyperbolic and three-parameter asymptotic hyperbolic model provided the best fit to a combined data of cereal rye shoot mass and N remaining, respectively. Both hyperbolic decay models showed a good fit for belowground mass decomposition and N release for both CCs. Cereal rye had a poorer fit than hairy vetch for mass and N remaining of both above and belowground mass. The best-selected decay models can be used to estimate the decomposition and N release rates of hairy vetch and cereal rye above and belowground residue in a similar environment. |
| first_indexed | 2024-03-10T19:50:46Z |
| format | Article |
| id | doaj.art-99da432376fb4ec581d9490a2724c779 |
| institution | Directory Open Access Journal |
| issn | 2073-4395 |
| language | English |
| last_indexed | 2024-03-10T19:50:46Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agronomy |
| spelling | doaj.art-99da432376fb4ec581d9490a2724c7792023-11-20T00:26:13ZengMDPI AGAgronomy2073-43952020-05-0110570110.3390/agronomy10050701Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen ReleaseMadhav Dhakal0Gurbir Singh1Rachel L. Cook2Taylor Sievers3USDA-ARS, Sustainable Water Management Research Unit, 4006 Old Leland Road, Leland, MS 38756, USADelta Research and Extension Center, Mississippi State University, P.O. Box 197, Stoneville, MS 38776, USADepartment of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USAOakland City University, Oakland City, IN 47660, USAEmpirical models could help us to understand the process of plant residue decomposition and nutrient release into the soil. The objective of this study was to determine an appropriate model to describe the decomposition of hairy vetch (<i>Vicia villosa</i> Roth) and cereal rye (<i>Secale cereale</i> L.) cover crop (CC) residue and nitrogen (N) release. Data pertaining to above and belowground CC residue mass loss and N release for up to 2633 cumulative decomposition degree days (112 d) after litterbag installation were obtained from two cropping system experiments, a 1-yr study conducted in 2015 and a 2-yr study during 2017 to 2018 in the humid subtropical environment of southern IL, USA. Six exponential and two hyperbolic models were fit to percent mass and N remaining data to find the one with minimum Akaike information criterion (AIC) and residual sum of squares. Modified three-parameter single exponential and two- or three-parameter hyperbolic models best met the assumed criteria of selection for above and belowground CC residue, respectively. Fitting a double exponential model to combined data for percent mass and N remaining identified two mass and N pools, a fast and a slow pool with different rate constants. A five-parameter double exponential with an asymptote met the preset criteria and passed all tests for normally distributed population, constant variance, and independence of residuals at α = 0.05 when fit to combined data of hairy vetch shoot mass and N remaining. However, a two-parameter hyperbolic and three-parameter asymptotic hyperbolic model provided the best fit to a combined data of cereal rye shoot mass and N remaining, respectively. Both hyperbolic decay models showed a good fit for belowground mass decomposition and N release for both CCs. Cereal rye had a poorer fit than hairy vetch for mass and N remaining of both above and belowground mass. The best-selected decay models can be used to estimate the decomposition and N release rates of hairy vetch and cereal rye above and belowground residue in a similar environment.https://www.mdpi.com/2073-4395/10/5/701cover cropcereal ryehairy vetchdecompositionnitrogen releaseexponential and hyperbolic models |
| spellingShingle | Madhav Dhakal Gurbir Singh Rachel L. Cook Taylor Sievers Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release Agronomy cover crop cereal rye hairy vetch decomposition nitrogen release exponential and hyperbolic models |
| title | Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release |
| title_full | Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release |
| title_fullStr | Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release |
| title_full_unstemmed | Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release |
| title_short | Modeling Hairy Vetch and Cereal Rye Cover Crop Decomposition and Nitrogen Release |
| title_sort | modeling hairy vetch and cereal rye cover crop decomposition and nitrogen release |
| topic | cover crop cereal rye hairy vetch decomposition nitrogen release exponential and hyperbolic models |
| url | https://www.mdpi.com/2073-4395/10/5/701 |
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