Soil structure dynamics in annual croplands under controlled traffic management

• Published in: Canadian Journal of Soil Science 2019-06, Vol.99 (2), p.146-160
• Main Authors: Guenette, Kris G, Hernandez-Ramirez, Guillermo, Gamache, Peter, Andreiuk, Roger, Fausak, Lewis
• Format: Article
• Language: English
• Subjects: Agglomeration; Agricultural equipment; Agricultural land; Agricultural production; Agricultural resources; Agricultural technology; agriculture durable; Agronomy; Bulk density; compactage; Compaction; Control equipment; controlled traffic; Crop yield; Crops; Farm management; Management systems; Porosity; porosité; qualité physique du sol; régulation de la circulation; Soil characteristics; Soil compaction; Soil dynamics; Soil improvement; Soil management; soil physical quality; Soil porosity; Soil quality; Soil structure; sustainable agriculture
• ISSN: 0008-4271; 1918-1841; 1918-1833
• DOI: 10.1139/cjss-2018-0117

Soil samples were collected from commercial agriculture sites within western Canada that were subjected to compaction from farm equipment in both conventional (imposed) traffic and controlled traffic regimes. Soil characteristics such as bulk density, pore volume fractions, and unsaturated hydraulic conductivity were compared with soil physical quality parameters, such as S-index and mass fractal aggregation between trafficked and untrafficked field areas. Our results showed that untrafficked soil characteristics displayed substantial improvements over those exposed to equipment compaction. Untrafficked soils in the controlled traffic regime exhibited total porosity improvements up to 15% in more than half of the study sites. In addition, spatial reductions of equipment compaction increased the volume of soil pore diameters associated with preferential water transmission from 40% to 180%. Changes in these soil characteristics within untrafficked soils correlated well with enhancements in the soil structure metrics, as improvements to the S-index were coupled with evidence of hierarchical aggregation. Irrespective of the positive changes to soil structure, significant increases in crop yield were rarely observed in favor of a controlled traffic regime. Our results suggest that the integration of controlled traffic farming into management systems may take several years for the benefits to soil physical quality to translate into observable improvements in crop yield.