Does the applied gauge-wheel loads have influence on seeding depth and soil structure?

Abstract

The inadequate use of farming machinery could have negative impacts on soil structure and crop growth. During planting, a row-unit downforce system is used to reach and maintain a target seeding depth by applying downward forces to the planter’s gauge-wheels. These forces are transferred to the soil and can increase the soil bulk density resulting in soil compaction. This study aimed to evaluate if gauge-wheel load, created by a hydraulic downforce system, have influence on seeding depth, soil cone index and bulk density using downforce in active (dynamic) and fixed (static) operational modes during cotton sowing. The test was conducted under a no-tillage loamy sand soil. A six row John Deere Max Emerge Plus planter set to 91 cm row spacing was equipped with a hydraulic downforce system. For the static operational mode of the downforce mechanism, five load levels were tested: NDF (Row-unit weight), Low – 535 Newtons (N), Medium 667 N, High – 890 N, and Very High – 1112 N. Four loads were evaluated using the dynamic mode: same low and medium loads as in manual mode, and also 756 N and 867 N, which were considered as High and Very High, respectively. When the static mode was used, the applied load exceeded the target load, especially when 890 and 1112 N were applied. Overall, the applied final load was close to the target and exhibited less variability when the dynamic mode was used compared to the static mode. As the downward forces increased, seeding depth increased with less variability.