Stored Grain pack factor measurements for soybeans, grain sorghum, oats, barley, and wheat

R. Bhadra, M. E. Casada, A. P. Turner, M. D. Montross, S. A. Thompson, S. G. McNeill, R. G. Maghirang, J. M. Boac

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Grain and oilseed crops stored in bins undergo compaction due to overbearing pressure of the grain inside the structure. Thus, volume measurements of grain in bins need to be combined with the amount of packing (usually called pack factor) in addition to the initial density so that the mass in the structure can be calculated. Multiple pack factor prediction methods are in use in the grain industry, but they have only been validated in the literature and compared with field data for corn and hard red winter wheat. Predictions from WPACKING, the program in ASABE Standard EP413.2, and two standard USDA methods, the USDA Risk Management Agency (RMA) and USDA Farm Service Agency-Warehouse Licensing and Examination Division (FSA-W) methods, were compared to field measurements of 92 bins containing soybeans, grain sorghum, oats, barley, or soft white or durum wheat. The WPACKING predictions had the lowest absolute average error of predicted mass for soybeans, grain sorghum, barley, and wheat, while the FSA-W method had the lowest error for oats. The RMA method gave the largest prediction errors for all five crops and struggled especially with the low-density, high-compaction crops oats and barley, giving average percent absolute errors near or above 10% in both cases. Overall, WPACKING, the RMA method, and the FSA-W method had average percent absolute errors of 2.09%, 5.65%, and 3.62%, respectively, for the 92 bins. These results can be used to improve pack factor predictions for the grain industry.

Original languageEnglish
Pages (from-to)747-757
Number of pages11
JournalTransactions of the ASABE
Issue number2
StatePublished - 2018

Bibliographical note

Publisher Copyright:
© 2018 American Society of Agricultural and Biological Engineers.


  • Barley
  • Grain
  • Grain sorghum
  • Oats
  • Pack factor
  • Sorghum
  • Soybeans
  • Steel and concrete bins
  • Stored grain inventory
  • Test weight
  • Wheat

ASJC Scopus subject areas

  • Forestry
  • Food Science
  • Biomedical Engineering
  • Agronomy and Crop Science
  • Soil Science


Dive into the research topics of 'Stored Grain pack factor measurements for soybeans, grain sorghum, oats, barley, and wheat'. Together they form a unique fingerprint.

Cite this