High-capacity grain carts that can hold more than 1,000 bu. of grain are in high demand this year as farmers look for ways to eliminate lag time during harvest. Jerry Ecklund, advertising manager for Unverferth Manufacturing, outlines what you need to know to size one up:

Capacity. Carts considered “high capacity” can carry at least 1,000 bu. of grain, the size needed to fill a semi. However, optimum size will vary by farm operation, combine size, and region. “In Canada and some of the western states, where load laws permit you to haul a semi plus a 500-bu. pup trailer, 1,500-plus carts are more appealing,” Ecklund says.

Auger design. Carts can have either one or two unloading augers. Manufacturers that offer single augers claim they provide better all-round visibility and easier cleanout than dual-auger carts. Manufacturers of dual-auger carts claim they move more grain faster.

Auger size. Unloading augers on high-capacity carts typically range from 18 to 24 in. in diameter. The bigger the auger, the faster the unloading speed.

Unloading speed. Carts can unload grain in as fast as 90 sec., or 1,090 bu./min. Faster speeds reduce wait time for the semi and give the grain cart more time to catch up to the combine after grain is unloaded.

Undercarriage options. Undercarriages are being redesigned to reduce the weight and stress on each axle. Options include single, dual, and triple axles, single wheels, walking tandem dual wheels, in-line steerable tandem wheels, and tracked undercarriages. Choice depends on size of cart, farming practices, and soil conditions. Jodi DeJong-Hughes, University of Minnesota Extension education, says grain carts can compact soil up to 3 ft. deep, which can reduce crop yields. Keeping axle loads under 10 tons can localize compaction to the top 6 to 10 in. of soil. “Look for dual axles, inline tandems, and large combine or flotation tires to minimize the effect on soil porosity," DeJong-Hughes says.

Tractor horsepower. Bigger carts require more horsepower to pull. Ecklund recommends a 200-hp tractor, minimum, for a 1,000-bu. cart. Consult your dealer to calculate horsepower needed for both pulling and controlling a loaded cart in the field. Also make sure the tractor has the required PTO to power the unloading auger.