Date of Graduation

12-2016

Document Type

Thesis

Degree Name

Bachelor of Science

Degree Level

Undergraduate

Department

Crop, Soil and Environmental Sciences

Advisor/Mentor

Brye, Kristofor

Committee Member/Reader

Popp, Jennie

Committee Member/Second Reader

Wood, Lisa

Abstract

The Alluvial Aquifer is the shallowest and most heavily used groundwater aquifer in the Lower Mississippi River Valley, particularly in the Delta region of eastern Arkansas. However, the Alluvial Aquifer is being depleted faster than the rate of recharge, primarily due to excessive withdrawals for irrigated crop production. Since extensive irrigation in the highly agriculturally productive Delta region of eastern Arkansas has been a main culprit in the groundwater depletion issues the region faces, a better understanding of how ecological factors and/or agricultural best management practices could possibly increase infiltration, to consequently increase recharge, are needed in order to either slow down or reverse the declining aquifer levels through the Delta region of eastern Arkansas. Therefore, the objective of this study was to evaluate the effects of landuse on surface water infiltration into alluvial and loessial soils in the Delta region of eastern Arkansas. Landuse combinations of interest included conventional and no-tillage agricultural practices, deciduous and coniferous forests, and native/natural grasslands. Replicate infiltration measurements were conducted using a double-ring infiltrometer, with a 15-cm inner-ring diameter, across multiple sites representing each of the five landuses. Despite the initial soil water content being greater (P < 0.05) in the grassland than in all other ecosystems, the overall infiltration rate into the deciduous forest ecosystem (1.2 cm hr-1) was greater (P < 0.05) than all other landuse types, which did not differ and averaged 0.10 cm hr-1. In addition, though the slope of the relationship between the natural logarithm of the infiltration rate versus the mid-point of time was unaffected (P > 0.05) by landuse, the intercept parameter differed (P < 0.05) among landuses. Results of this study demonstrated that landuse significantly affects infiltration processes in the fine-textured loessial and alluvial soils in the Delta region of eastern Arkansas; thus, further research is warranted into factors that can increase surface infiltration and potentially groundwater recharge.

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