| Cover crops improve soil health and reduce the risk of soil erosion. However, their impact on the carbon dioxide equivalence (CO2e) is unknown. Therefore, the objective of this 2-yr study was to quantify the effect of cover crop-induced differences in soil moisture, temperature, organic C, and microorganisms on CO2e, and to develop machine learning algorithms that predict daily N2O-N and CO2-C emissions. The prediction models tested were multiple linear regression, partial least square regression, support vector machine, random forest (RF), and artificial neural network. Models' performance was accessed using R-2, RMSE and mean of absolute value of error. Rye (Secale cereale L.) was dormant seeded in mid-October, and in the following spring it was terminated at corn's (Zea mays L.) V4 growth stage. Soil temperature, moisture, and N2O-N and CO2-C emissions were measured near continuously from soil thaw to harvest in 2019 and 2020. Prior to termination, the cover crop decreased N2O-N emissions by 34% (p = .05), and over the entire season, N2O-N emissions from cover crop and no cover crop treatments were similar (p = .71). Based on N2O-N and CO2-C emissions over the entire season and the estimated fixed cover crop-C remaining in the soil, the partial CO2e were -1,061 and 496 kg CO2e ha(-1) in the cover crop and no cover crop treatments, respectively. The RF algorithm explained more of the daily N2O-N (73%) and CO2-C (85%) emissions variability during validation than the other models. Across models, the most important variables were temperature and the amount of cover crop-C added to the soil. |
作者：Clay, Sharon A A;Joshi, Deepak R R;Clay, David E E;Moriles-Miller, Janet;Daigh, Aaron L M;Reicks, Graig;Westhoff, Shaina
作者单位：Univ Nebraska;North Dakota State Univ;South Dakota State Univ
期刊名称：AGRONOMY JOURNAL
期刊影响因子：0.0
出版年份：2024
出版刊次：116(3)
原文传递申请：江苏省科技资源（工程技术文献）统筹服务平台