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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #304695
Title: Agricultural policy environmental eXtender model simulation of climate change impacts on runoff from a small no-till watershed

Author
item GAUTAM, SAGAR - South Dakota State University
item MBONIMPA, ERIC - South Dakota State University
item KUMAR, SANDEEP - South Dakota State University
item Bonta, James - Jim
item LAL, RATTAN - The Ohio State University

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2015
Publication Date: 3/1/2015
Citation: Gautam, S., Mbonimpa, E., Kumar, S., Bonta, J.V., Lal, R. 2015. Agricultural policy environmental eXtender model simulation of climate change impacts on runoff from a small no-till watershed. Journal of Soil and Water Conservation. 70(2):101-109. doi:10.2489/jswc.70.2.101.

Interpretive Summary: This study was conducted to evaluate the impacts of long-term management and climate on runoff from a small watershed with a rotation of continuous corn (CC) and a corn-soybean-rye (CSR, cover crop management) and managed with the no-till (NT) system. The Agricultural Policy Environmental eXtender (APEX) was used in this study, a field scale hydrologic model capable of simulating the management impacts on runoff. Measured watershed data from WS118 (0.79 ha) on the North Appalachian Experimental Watershed (NAEW) near Coshocton, Ohio were used for calibrating the model over a 12-yr period (2000 through 2011) under the two practices, and to aid in climate change studies. Simulated climate change impacts on runoff were investigated over 50 years using different temperature, precipitation and carbon dioxide (CO2) scenarios generated from the APEX model. The results indicate that the CSR rotation showed 37% lower simulated mean annual runoff compared with that of CC under the NT system during the 50-yr climate change period. The climate change scenarios indicated runoff was most sensitive to precipitation, and interactions of precipitation, temperature, and carbon dioxide concentrations. The highest increase of runoff (61%) was observed with 15% increase of precipitation, and the highest reduction in runoff (47%) with the 15% decrease in precipitation, demonstrating the magnification of hydrological system response to precipitation. The results demonstrate the benefits of cover crops in the CSR over the CC rotation under NT system, and show the significant impacts of climate change on runoff response from a small, upland, agricultural watershed. The results will be useful to scientists, producers, and conservation practitioners to aid in managing landscapes under a changing climate.

Technical Abstract: Long-term hydrologic data sets are required to quantify the impacts of management, and climate on runoff at the field scale where management practices are applied. This study was conducted to evaluate the impacts of long-term management and climate on runoff from a small watershed managed with no-till (NT) system. The Agricultural Policy Environmental eXtender (APEX), a field scale hydrologic model which is capable of simulating the management and climate impacts on runoff, was used in this study. The specific objectives of the study were to: (i) simulate the impacts of cropping management and tillage system on runoff and, (ii) simulate climate change impacts on runoff using different temperature, precipitation and carbon dioxide (CO2) scenarios generated from the APEX model. The study was conducted on a small watershed located on the North Appalachian Experimental Watershed (NAEW) near Coshocton, Ohio. This watershed (WS 118, ~0.79 ha) includes NT management with two periods of crop rotations: continuous corn (Zea mays L.) (CC; 2000-2005) and corn-soybean (Glycine max L.)-rye (Secale Cereale L.) (CSR; 2006-2011). The results from this study indicate that the CSR rotation showed 37% lower simulated mean annual runoff compared with that of CC under NT system. The climate change scenarios indicated runoff was most sensitive to the precipitation, and interactions of precipitation, temperature and carbon dioxide concentrations. The highest increase of runoff (61%) was observed with 15% increase of precipitation, and the highest reduction in runoff (47%) with the 15% decrease in precipitation, demonstrating the nonlinearity of hydrological systems. The results demonstrate the benefits of cover crops in the CSR over the CC rotation under NT system, and show the significant impacts of climate change on runoff response from a small, upland, agricultural watershed.