Scientists for the U.S. Department of Agriculture have completed a study focusing on optimal characteristics of tractor drive tires in tilled vs. no-till soil, finding that adjustments to tire pressure, size and tread design could make tractors more efficient and less disruptive to crops in no-till fields.
The 21-day study tested contact pressures of tractor drive tires on different types of soil to determine the impact variations of tire pressure, tire size and tread design had on soil compaction and the pulling efficiency and fuel efficiency of tractors, said a spokesman for the Agricultural Research Service (ARS), the research arm of the USDA.
The study was conducted because of the growing popularity of no-till farming as it enhances water infiltration into the soil, resulting in increased crop yields, less runoff and reduced soil erosion, said Thomas Way, co-author of the study and an agricultural engineer at the ARS' National Soil Dynamics Laboratory in Auburn.
``Contact pressures of tractor tires on loose, tilled soil had been measured in several previous studies,'' he said, ``but few, if any, previous studies had investigated contact pressures for tractor tires on structured soil, the soil that is characteristic of no-till systems.''
Mr. Way's co-author was Tadashi Kishimoto of the Obihiro University of Agriculture and Veterinary Medicine in Japan.
To obtain their results, the engineers ran a tractor tire equipped with six sensors on its tread in three bins containing different kinds of soil, Mr. Way said. The different soils were a ``structured clay soil'' indicative of no-till conditions, and ``loose sandy loam'' and ``loose clay loam'' expected in conventional tilled fields, he said.
The researchers expect that their results may be useful to tractor tire designers and manufacturers in determining load values-weight put on the tire-and tire pressure, as well as the size of the lugs on tires' treads, which make considerable contact with the soil and can affect compaction, Mr. Way said. The researchers made no specific recommendations about tractor tire design or use, he said.
The results of Mr. Way's and Mr. Kishimoto's study are available in American Society of Agricultural Engineers' Paper 021123, ``Interface Pressures for a Tractor Drive Tire on Structured Soil.''