Air seeders use standard drill openers or unit planters on a framework similar to a chisel plow. A very large, towed hopper meters seed and moves the seed by airflow to the furrow opening device. Hopper capacity varies from 200 to 400 bushels. Some systems have an additional hopper that supplies fertilizer in concert with the seeding operation. The seeding units vary in width from 28 to 60 feet. Row spacing varies from 7.5 to 30 inches depending on the type of crop. Different types of fluted metering systems are available to supply very low to very high rates of different sized seed or fertilizer. The systems use electronic seed counting, and seeding rates can be monitored or changed on-the-go from the tractor cab. Many of the same options to improve grain drill efficacy in different soil conditions are available for air seeders.
Air seeders are designed for high-acreage output on clean-tilled land or land with heavy crop residue. They can operate on rolling land but are not suited for rocky or rough terrain.