Date of Graduation

Spring 2021

Degree

Master of Science in Agriculture

Department

College of Agriculture

Committee Chair

Melissa Remley

Abstract

Sustainable use of water resources in Southwest Missouri requires a better understanding of factors that influence groundwater use by crop producers. The objective of this study was to assess the influence of weather patterns and edaphic factors on water used for agricultural irrigation. Groundwater withdrawal data from 14 high-use agricultural irrigation wells were monitored between 2009 and 2016 as part of the Southwest Missouri Irrigation Project. Stepwise and linear regression was used to assess the relationship of weather and edaphic factors in response to annual water use from each well. Precipitation volume, number of precipitation events, average maximum and minimum temperature, drought monitor index, soil organic matter, and infiltration rate all showed individual significance using linear regression. Stepwise model showed precipitation volume, soil organic matter, and average minimum temperature as significant factors. Along with assessing irrigation data, a study was conducted to measure soil microbial respiration response in relation to percent water filled pore space and crop residue. Treatments included 15, 30, 45, and 60 percent water filled pore space as well as corn, soybean, and wheat residues. A mixed model analysis of variance was used to describe soil microbial respiration response to treatments. Results showed no significant difference between crop residue types, percent water filled pore space, and their interaction.

Keywords

irrigation, soil microbial respiration, weather factors, edaphic factors, crop residue, water filled pore space

Subject Categories

Agricultural Science | Natural Resources and Conservation | Other Plant Sciences | Water Resource Management

Copyright

© Shirley M. Dobbs

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