Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Davis, Jeremiah

Committee Member

Larson, Erick

Committee Member

Montross, Michael

Committee Member

Raper, Randy

Date of Degree

5-12-2012

Document Type

Dissertation - Open Access

Major

Biological Engineering

Degree Name

Doctor of Philosophy (Ph.D)

College

James Worth Bagley College of Engineering

Department

Department of Agricultural and Biological Engineering

Abstract

Grain production in the Mid-South US has exceeded traditional grain bin storage capacity in recent years. Alternative grain storage methods were adopted. One method was grain bag storage. This system has been used for silage and high moisture corn storage for decades and has been employed for dry grain in other regions of the world, but little research was available to describe the internal environment of the grain bags and its effects on grain quality. Weather conditions, agricultural methods, and cultural practices vary; therefore further research was required to assess this storage practice and describe best management practices for the local region. The objectives of this study were to develop a system and method to monitor the grain bag internal environment, to determine the internal environment and quality of dried grains stored in grain bags, and to determine the internal environment and quality of harvest moisture and condition corn stored in grain bags. An instrumentation system of thermocouples and relative humidity sensors was successfully developed. Fourier analysis was applied and sampling interval less than 10 hours was required to fully describe the grain bag environment. Commercially conditioned (dried and blended) corn (14.1 % MCwb) and soybeans (10.4 %MCwb) were stored in grain bags for 20 and 16 weeks, respectively. Corn immediately after harvest (17.1 %MCwb) was stored for 12 weeks. There were significant differences between grain in the center of the bag and peripheral temperature, with the periphery closely tracking ambient conditions. Psychrometric calculations (humidity ratio and dew-point) indicated that moisture migrated to the bag edges. Temperature within the grain mass never fell below the temperature required for condensation, condensation at the bag internal surface was likely. Grab samples did not reflect significant differences in grain moisture content across the bag profile. Geostatistical methods were used to interpolate the thermal environment of the grain bags; ordinary kriging was the best method of interpolation. Commercially conditioned corn maintained its quality while in storage, while soybeans lost one US grade. Harvest condition corn deteriorated in quality to US Sample grade while in storage. Short storage periods for early harvest corn are recommended.

URI

https://hdl.handle.net/11668/17921

Download

Share

COinS