Variability of gauge-wheel loads resulting from a hydraulic downforce system and the impacts on corn seeding depth and emergence

The quality and efficiency of agricultural operations is a function of how the machinery and implements are performing. Current hydraulic downforce systems on the market could work using two operational modes, static and dynamic. Both, if not set properly can reduce the quality of crop planting. This work aimed to evaluate if the quality of corn planting is affected by the downforce operational mode or gauge-wheel loads. Planting was conducted using a six-row John Deere Max Emerge Plus planter equipped with a commercial hydraulic downforce system. For the static operational mode, six gauge-wheel load levels were tested: No downforce (NDF – Row-unit weight only), Very Low – 444 Newtons (N), Low – 535 N, Medium 667 N, High – 890 N, and Very High – 1112 N. Five loads were evaluated using dynamic mode: same very low, low and medium loads as in static mode, and also 756 N and 867 N, which were designated as High and Very High, respectively. The data was collected through the time, according to statistical control process specifications in a complete randomized blocks design with four replications. Data of seeding depth and emergence was collected from every treatment/replication. Gauge-wheel load variability was larger when not a specific load was applied (only row-unit weight). Higher loads in dynamic or static mode reduced seeding depth variability. The different gauge-wheel loads evaluated either on dynamic and static modes had positive correlation with seeding depth. There was a positive association between static-mode applied loads, seeding depth and emergence velocity index.