02622nas a2200277   4500008004100000020001400041245011400055210006900169260001200238520171500250653003001965653002401995653002302019653003102042653002702073653001702100653001402117653002602131653003602157653001602193100002302209700002502232700002002257700002402277856004302301       2015                        eng d  a1944-797300aUntangling the effects of shallow groundwater and soil texture as drivers of subfield-scale yield variability0 aUntangling the effects of shallow groundwater and soil texture a  c07/20153 aWater table depth (WTD), soil texture, and growing season weather conditions all play critical roles in determining agricultural yield; however, the interactions among these three variables have never been explored in a systematic way. Using a combination of field observations and biophysical modeling, we answer two questions: (1) under what conditions can a shallow water table provide a groundwater yield subsidy and/or penalty to corn production?; and, (2) how do soil texture and growing season weather conditions influence the relationship between WTD and corn yield? Subfield-scale yield patterns during a dry (2012) and wet (2013) growing season are used to identify sensitivity to weather. Areas of the field that are negatively impacted by wet growing seasons have the shallowest observed WTD (< 1 m), while areas with consistently strong yield have intermediate WTD (1-3 m). Parts of the field that perform consistently poorly are characterized by deep WTD (> 3 m) and coarse soil textures. Modeling results find that beneficial impacts of shallow groundwater are more common than negative impacts under the conditions studied, and that the optimum WTD is shallower in coarser soils. While groundwater yield subsidies have a higher frequency and magnitude in coarse-grained soils, the optimum WTD responds to growing season weather at a relatively constant rate across soil types. We conclude that soil texture defines a baseline upon which WTD and weather interact to determine overall yield. Our work has implications for water resource management, climate/land use change impacts on agricultural production, and precision agriculture. This article is protected by copyright. All rights reserved.10a0402 Agricultural systems10a0486 Soils/pedology10a1813 Eco-hydrology10a1829 Groundwater hydrology10aagroecosystem modeling10aAgroIBIS-VSF10aHydrus-1D10aPrecision agriculture10asoil-plant-atmosphere continuum10awater table1 aZipper, Samuel, C.1 aSoylu, Mehmet, Evren1 aBooth, Eric, G.1 aLoheide, Steven, P.  uhttp://dx.doi.org/10.1002/2015WR017522