U.S Corn Export System
This U.S. Grains Council 2018/2019 Corn Export Cargo Quality Report provides advance information about corn quality by evaluating and reporting quality attributes when the corn is ready to be loaded onto the ocean-going vessel or railcar for export. Corn quality includes a range of attributes that can be categorized as:
- Intrinsic quality characteristics – Protein, oil and starch concentrations, and kernel hardness and density, are all intrinsic quality characteristics; that is, they are contained within and are of critical importance to the end-user. Since they are non-visual, they can only be determined by analytical tests.
- Physical quality characteristics – These attributes are associated with the outward visible appearance of the kernel or measurement of the kernel characteristics. Characteristics include kernel size, shape and color; moisture content; test weight; total damaged and heat-damaged kernels; broken kernels; and stress cracks. Some of these characteristics are measured when corn receives an official USDA grade.
- Sanitary quality characteristics – These characteristics indicate the cleanliness of the grain. Attributes include presence of foreign material, odor, dust, rodent excreta, insects, residues, fungal infection and non-millable materials.
The intrinsic quality characteristics are impacted significantly by genetics and growing season conditions and typically do not change at the aggregate level as corn moves through the marketing system. If the measured values of the intrinsic characteristics differ between harvest and export at the aggregate level, the differences can be due, in part, to normal random variation in sampling. On the other hand, the physical and sanitary characteristics can change as corn moves through the marketing channel. The parties involved in corn marketing and distribution use operating practices (such as cleaning, drying and conditioning) at each step in the channel to increase uniformity, prevent or minimize the loss of physical and sanitary quality and to meet contract specifications.
The Harvest Report assesses the quality of the recently harvested corn crop as it enters the marketing system. The Export Cargo Report provides information on the impact of subsequent practices, including cleaning, drying, handling, blending, storing and transporting of the crop up to the point where it is being loaded for export. To provide the backdrop for this assessment, the following sections describe the marketing channel from farm to export, the practices applied to corn as it moves through the marketing channel and the implications of these practices on corn quality. Lastly, the inspection and grading services provided by USDA GIPSA or an official service provider are reviewed.