Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Krutz, L. Jason
Committee Member
Reynolds, Daniel
Committee Member
Locke, Martin
Committee Member
Golden, Bobby
Committee Member
Irby, Jon
Date of Degree
12-13-2019
Original embargo terms
Worldwide
Document Type
Dissertation - Open Access
Major
Plant and Soil Sciences (Agronomy)
Degree Name
Doctor of Philosophy
College
College of Agriculture and Life Sciences
Department
Department of Plant and Soil Sciences
Abstract
Mid-southern USA soybean [Glycine max (L.) Merr.] producers are being pushed to increase adoption of conservation tillage systems as a means of increasing the application efficiency of gravity flow irrigation systems. This research was conducted to determine whether the efficiency of furrow-irrigation systems could be manipulated through conservation tillage systems while maintaining soybean productivity and profitability. Three experiments were conducted near Stoneville, MS on a Dubbs silt loam (Fine-silty, mixed, active, thermic Typic Hapludalfs) to determine the effects of reducing tillage and increasing ground cover residues on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs. In experiment 1, transitioning from conventional tillage to a conservation tillage system had no adverse effect on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, or net returns above specified costs when subsoiling was included. For experiment 2, replacing subsoiling with a cereal rye or tillage radish cover crop in a conservation tillage system either had no effect or reduced irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs up to 41%. In experiment 3, independent of cover crop, reducing tillage to only furrow creation had no adverse effect on irrigation application efficiency, irrigation water use efficiency, soybean grain yield, and net returns above specified costs relative to a conservation tillage system with subsoiling. Conservation tillage systems that include subsoiling maximize irrigation application efficiency and irrigation water use efficiency while minimizing adverse effects on yield and net returns relative to conservation tillage systems that further reduce tillage and/or increase ground coverage with cover crops. Our data indicate that soybean producers in the mid-southern USA maximize furrow-irrigation functionality, yield, and profitability while minimizing risk by transitioning from a conventional tillage system to a conservation tillage system with subsoiling.
URI
https://hdl.handle.net/11668/16420
Recommended Citation
Bryant, Corey, "Maintaining agronomics, economics, and furrow-irrigation efficiency in mid-southern USA soybean conservation production systems" (2019). Theses and Dissertations. 2990.
https://scholarsjunction.msstate.edu/td/2990
Comments
Conservation Tillage||Irrigation Efficiency||Cover Crops