Proceedings of the 2019 Mississippi Water Resources Conference

Year: 2019 Authors: Li Y., Tian D., Feng G., Feng L.

Climate extreme events in the forthcoming decades are most likely to affect agriculture production and water consumption. Cover crops could be potentially considered as a strategy to mitigate the negative effects of climate extremes. However, extreme climate events were not well determined, and how will the cover crop affect each water balance component under different climate extreme conditions has not been fully explored in Mississippi State. In this study, future climate data were projected under two Representative Concentration Pathways (RCPs) 4.5 and 8.5 from statistically downscaled outputs of ten GCMs (General Circulation Models) provided by Coupled Model Inter-comparison Project - Phase 5 (CMIP5). A variety of diagnostic methods were used to determine extreme temperature, heavy precipitation, and drought based on data in the past (1956-1985), present (1986-2015), and future (2020-2049 and 2050-2079). Then the calibrated and validated model, Root Zone Water Quality Model version 2 (RZWQM2), was applied to simulate crop yields, evapotranspiration (ET), seepage, and runoff under historical and projected future climate extreme conditions for cover crop and non-cover crop scenarios in Pontotoc, Mississippi. A set of climate indices were calculated using daily data during growing season to investigate relationships of climate indices, crop yield and water balance components. The effect of cover crop on crop yield, ET, runoff and percolation under different climate extreme conditions in a Maize-soybean Rotation cropping system will be presented and discussed.