Emergence of Soybean and Canola Plants as Affected by Soil Compaction from a Seeder Press Roller

Changes in soil properties under mechanical stress significantly influence the emergence and growth of crops, with different crops responding differently to these changes. To explore the impact of different soil compaction states on crop growth, field experiments were conducted in 2022 and 2023 in sandy loam soil in Manitoba, Canada. The crops (canola and soybean) were planted under three compaction levels created by a seeder’s press roller: no press roller (P0), one pass of the press roller (P1), and two passes of the press roller (P2). Soil mechanical properties and plant growth were measured for each treatment. The results indicated that soil shear strength increased significantly with each level of compaction from P0 to P1 and from P1 to P2, while soil surface resistance remained largely unaffected. Interestingly, soybean and canola responded differently to soil compaction. Soybeans showed no significant changes in emergence speed or final plant population across the three treatments. Conversely, canola exhibited over a 50% increase in emergence speed and more than a 100% increase in final plant population with either one (P1) or two passes (P2) of the press roller, compared to the no press roller (P0) treatment. These findings provide valuable guidance for agricultural producers and engineers in adjusting the down pressure of seeder press wheels when planting different crops.