Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Firth A., Brooks J., Locke M., Morin D., Brown A., Baker B.

Agriculture is the greatest contributor to overall consumptive water use with deleterious effects seen in river depletion and groundwater over draft. Despite negative documented effects of agricultural land use (i.e. soil erosion, compaction, nutrient runoff) on critical natural resources (i.e. water), food production must increase in order to meet the demands of a rising human population. Given the environmental and agricultural productivity concerns of intensely managed soils, there is a growing interest in conservation practices that mitigate the negative effects of crop production and enhance environmental integrity. In the Mississippi Alluvial Valley (MAV) region of Mississippi, USA, the adoption of cover crop (CC) and no-till (NT) management practices has been low because of a lack of research specific to the regional nuisances. Therefore, this study assed the long-term soil physical responses from integrating CC and NT management to agricultural soils in the MAV region of Mississippi. It was hypothesized that the combination of a diverse CC mixture and NT management would provide more favorable soil physical properties compared with single CC mixtures or tillage treatments. Bulk density, aggregate stability, water holding capacity and water infiltration were measured after 5 years of CC and NT treatments. Data on soil properties were subjected to analysis of variance to assess the effects of tillage, CC and time on soil physical response (bulk density, aggregate stability, moisture retention, moisture porosity, water infiltration). Generalized linear mixed models were used to determine how dependent variables interact with independent treatments. Bulk density was found to be significantly lower in NT plots and aggregate stability was greatest in plots with a single CC species (elbon rye) as a CC. No differences were found in water infiltration; however, data collection may not have used optimal methods. Water porosity was greatest in a NT-CC combination, suggesting that conservation agriculture can improve soil physical characteristics that are linked with decreased water runoff.