The Secretary is authorized to investigate the handling, weighing, grading, and transportation of grain and to fix and establish (1) standards of kind, class, quality, and condition for corn, wheat, rye, oats, barley, flaxseed, sorghum, soybeans, mixed grain, and such other grains as in the judgment of the Secretary the usages of the trade may warrant and permit, and (2) standards or procedures for accurate weighing and weight certification and controls, including safeguards over equipment calibration and maintenance, for grain shipped in interstate or foreign commerce; and the Secretary is authorized to amend or revoke such standards or procedures whenever the necessities of the trade may require.