Seed Cleaning and Sorting

removing foreign impurities (seeds of other crop plants and weeds and dead waste) from seed material and breaking the material down in order to identify the most economically valuable seed for planting. With combine harvesting, seed cleaning and sorting begins in the field, in the combine itself. The process is completed at a grain cleaning and drying station after the harvest, and sometimes additional operations are conducted before sowing. Seed cleaning and sorting is done by grain cleaning machines, whose operation is based on differences in dimensions (thickness, width, and length), weight, aerodynamic qualities (seeAERODYNAMICS OF SEEDS), shape, and surface texture of the seeds.

Pneumatic sorting tables are used to separate seeds by weight, and a grain cleaning column is used for cleaning seeds from other substances with different aerodynamic properties. Gravity seed cleaners and electromagnetic seed cleaning machines sort the seeds by shape and surface texture.

The cleaned seeds of corn, cotton, sugar beets, and sunflower are divided according to size into groups. This ensures even sowing, sprouting, and development of the plants.