Effect of increased deflection tire technology on soil compaction

Authors: TEKESTE, MEHARI - Iowa State University; Way, Thomas - Tom; BIRKENHOLZ, WAYNE - Bridgestone Americas Tire Operations, Llc; BRODBECK, SALLY - Precision Inflation, Llc

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2022
Publication Date: 2/21/2023
Citation: Tekeste, M., Way, T.R., Birkenholz, W., Brodbeck, S. 2023. Effect of increased deflection tire technology on soil compaction. Journal of the ASABE. 66(1):75-84. https://doi.org/10.13031/ja.14794.
DOI: https://doi.org/10.13031/ja.14794

Interpretive Summary: Soil compaction is often detrimental to crop production, as compaction can inhibit crop root growth, thereby reducing the ability of roots to uptake water. Compaction can be caused by vehicle traffic on soil, and in row-crop production, traffic during planting can cause compaction detrimental to crop growth and yield. Starting around the year 2000, agricultural tire manufacturers are now offering new types of radial-ply tires designed to operate with greater tire deflections than conventional radial-ply tires. A field experiment was conducted on a loam soil at the Iowa State University farm (Boone, Iowa) using Increased Flexion (IF) tires. Two tire inflation pressure configurations were used on dual front (Firestone IF 420/85R34) and dual rear (Firestone IF 480/80R50) tires of a John Deere 8310R mechanical front-wheel drive (MFWD) tractor, and transport tires (the four tires at the middle of the planter, Super single 445/50R22.5) on a John Deere DB60 planter. Potential soil compaction from the tractor and planter transport tires, as indicated by mechanical stresses in soil, is expected to be greater for standard radial tire inflation pressures (relatively high tire air pressures) than for IF radial tire inflation pressures (relatively low tire air pressures).

Technical Abstract: New agricultural tire standards, designated as Increased Flexion (IF) and Very High Flexion (VF), have been introduced for agricultural machines. These tires provide larger contact areas than a standard radial tire carrying the same load. Limited studies have been conducted on how the newly adopted IF tires and precision tire inflation pressure management systems affect soil compaction, fuel economy, and crop yield response. The purpose of the study was to investigate the effects of field and transport (road) tire inflation pressure settings of row-crop agricultural tractor and planter tires on soil compaction. A completely randomized design experiment was conducted on a loam soil at the Iowa State University farm at Boone, Iowa for two tire inflation pressure levels on dual front (Firestone IF 420/85R34) and dual rear (Firestone IF 480/80R50) tires on a John Deere 8310R MFWD tractor, and transport tires (Super single 445/50R22.5) on a John Deere DB60 central-fill planter. Soil compaction was measured using Stress State Transducers (SSTs) buried at 150 mm and 300 mm depths beneath the untrafficked soil surface. The soil cone penetration resistance was measured at tire centerline before and after tractor and planter tire passes. After the tractor and planter passes, rut depth was also measured at tire centerline. Peak octahedral normal stress (ONS) and the corresponding octahedral shear stress (OSS) values in soil were calculated from the SST data. The peak ONS for the rear tractor tire was significantly greater for the Standard Radial Tire Pressures treatment than for the IF Radial Tire Pressures treatment. The tire inflation pressure treatment did not significantly affect the peak ONS for the front tractor tire and the planter transport tire. For this tractor and planter configuration, soil stress results identify the rear tractor tires as the main source of soil compaction during planting. The Standard Radial Tire Pressures treatment caused significantly greater soil cone index and soil rut depth compared with the IF Radial Tire Pressures (P < 0.05). Potential soil compaction from the tractor and planter transport tires, as indicated by soil stresses, is expected to be greater for standard radial tire inflation pressures than for IF radial tire inflation pressures.