Update:
January 8, 2021
PI Name: Kenneth Hellevang
Grant Title: Evaluating the Allowable Storage Time of Two Soybean Varieties at Two Moisture Levels at Typical Storage Temperatures (Modified to four moisture levels)
Objectives:
Evaluate the quality (microbial growth, oil quality, and germination) of soybean stored at selected temperatures (40°F, 5°F, and 72°F) and four moisture levels (11%, 13%, 15%, 17%) over 10 months
Completed Work:
The detailed research plan was designed, cooperators to supply the soybeans identified, and research apparatus and testing equipment obtained. Two freshly harvested soybean varieties (ND17009GT and XL80-23) were obtained from fields at harvest moisture contents of 11% and 9.5%. The harvested seeds were conditioned to four moisture levels of (11, 13, 15, and 17% wet basis), and are being stored at selected temperatures of 5°F, 40°F, 72°F, and a sequence of temperatures that represents North Dakota (ND) weather over 12 months. The start of the study was delayed from November 1 to December 1 due to the graduate student having COVID. Samples are being taken every two weeks for two months and then monthly afterward. Mold development, germinability, and oil quality parameters are being monitored throughout storage.
Preliminary Results:
It was observed that at the four moisture contents (11, 13, 15, and 17%), low values of mold count in CFU/ml were recorded on the first day of storage for both varieties. Soybean variety ND17009GT (17%) had a higher value of mold count in contrast to the XL80-23(17%) variety stored at 72°F after two weeks and four weeks. Both varieties at 15 and 17% stored at 72°F yielded >98% seed germination after the first two weeks of storage. Oil quality parameters (peroxide value, free fatty acid, and p-anisidine) measured were at very low percentage levels for all moisture contents and selected storage temperatures within the first two weeks of storage.
Preliminary Results:
For both stored soybean varieties (ND17009GT and XL80-23) at 11% and 13%, a lower mold count is expected in comparison to 15 and 17% for seeds stored at all the selected storage temperatures of 5°F, 40°F, and 72°F throughout storage. Germination is also expected to decrease in 15 and 17% seeds stored at 72°F as storage progresses. Likewise, oil quality, for 15 and 17% moisture seeds at 72°F is expected to record deterioration with an increase in FFA and PV values as storage progresses with lower values for stored seeds at 5F and 40F respectively. Only data from six months of storage will be available by June 2021, so additional funding to continue the research for the full 10-months will be requested.
Benefit to ND Soybean Farmers:
This research will provide information on allowable storage time for soybeans at four moisture contents and three temperatures, which will permit farmers to manage storage and maintain soybean quality. It will also complement research currently being done looking at carbon dioxide production from soybean, which is the common method of determining allowable storage time for cereal grains. The combination of research results will provide a sound basis for managing soybean in storage.
Update:
Analysis of data is continuing. Discrepancies between research results and existing recommendations have been observed.