Assessing the impacts of climate change and tillage practices on stream flow, crop and sediment yields from the Mississippi River Basin

Abstract

This study evaluated climate change impacts on stream flow, crop and sediment yields from three differ-ent tillage systems (conventional, reduced 1–close to conservation, and reduced 2–close to no-till), in theBig Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) modelwas applied to the BSRW using observed stream flow and crop yields data. The model was calibrated andvalidated successfully using monthly stream flow data (2001–2011).The model performances showed the regression coefficient (R²) from 0.72 to 0.82 and Nash–Sutcliffeefficiency index (NSE) from 0.70 to 0.81 for streamflow; R² from 0.40 to 0.50 and NSE from 0.72 to 0.86for corn yields; and R² from 0.43 to 0.59 and NSE from 0.48 to 0.57 for soybeans yields. The Long Ash-ton Research Station Weather Generator (LARS-WG), was used to generate future climate scenarios. TheSRES (Special Report on Emissions Scenarios) A1B, A2, and B1 climate change scenarios of the Intergov-ernmental Panel on Climate Change (IPCC) were simulated for the mid (2046–2065) and late (2080–2099)century. Model outputs showed slight differences among tillage practices for corn and soybean yields.However, model simulated sediment yield results indicated a large difference among the tillage practicesfrom the corn and soybean crop fields. The simulated future average maximum temperature showed ashigh as 4.8◦C increase in the BSRW. Monthly precipitation patterns will remain un-changed based onsimulated future climate scenarios except for an increase in the frequency of extreme rainfall eventsoccurring in the watershed. On average, the effect of climate change and tillage practice together didnot show notable changes to the future crop yields. The reduced tillage 2 practices showed the highestresponses of erosion control to climate change followed by the reduced tillage 1 and conventional tillagein this study.

Citation

Parajuli, P.B.; Jayakody, P.; Sassenrath, G.F.; Ouyang, Y. 2016.Assessing the impacts of climate change and tillage practices on stream flow, crop and sediment yields from the Mississippi River Basin. Agricultural Water Management. 168: 112-124. 13 p.  https://doi.org/10.1016/j.agwat.2016.02.005.