Degree Type

Thesis

Date of Award

2017

Degree Name

Master of Science

Department

Agronomy

Major

Sustainable Agriculture; Crop Production and Physiology

First Advisor

Mary Wiedenhoeft

Abstract

Small grains, such as, barley (Hordeum vulgare L.), oat (Avena sativa L.), rye (Secale cereale L.), triticale (X Triticosecale Wittmack) and wheat (Triticum aestivum L.) contribute to the proper functioning of organic row crop systems in Iowa and the upper Midwest. Besides producing grain and straw, which have value either as sold products or on-farm inputs, they are commonly used rotation crops that contribute functions such as forage legume establishment and weed suppression. Additionally, they may contribute to a suite of below ground functions that included soil quality improvement and disease suppression. However, small grains themselves are less profitable than corn (Zea mays L.) and soybean (Glycine max (L.) Merr.). Some of this has to do with production challenges to grain yield and grain quality, the latter being often more important than the former. Some of this may be dependent on economic considerations such as market options or a lack thereof. Additionally, these challenges and considerations are also intertwined with farmer perceptions, which can shape and be shaped by these different factors. The goal of this research was to use a variety of methodologies, specific to agronomy, sociology, and economics, to explore the present status of organic small grains in Iowa. This was achieved via a large-scale, mixed-methods study involving 41 farmers across the state, a set of three on-farm trials at seven farms, and an agronomic small-plot experiment at the Iowa State University Agricultural Engineering and Agronomy Farm. The mixed-methods study helped to highlight a range of production, economic and farmer perception-based factors and was useful in generating hypotheses for on-farm and on-station research. The latter two studies focused on oat. On-farm trials consisted of testing low-cost tactics such as oat density manipulations, physical weed control and planting oat as a monoculture followed by a mid-season cover crop vs. oat planting with a forage legume underseeding. On-station research further examined the effects of oat population density and delayed planting.

Copyright Owner

David Weisberger

Language

en

File Format

application/pdf

File Size

119 pages

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