Tractor passes and soil cone index interaction on direct drill and conventional tillage soil

RIVERO, D; JORAJURIA, D; BALBUENA, R; GILI A; BOMBEN, M; TOURN, M

Foz do Iguaco - Brazil

Congreso; XXXVII Brazilian Congress on Agricultural Engineering; 2008

In Argentina, soybean (Glycine max L.) is grown mainly on clayey soils (2.6 million ha). These soils are very susceptible to heavy traffic compaction. Soil penetration resistance, in fine textured soil, should not exceed 1200 kPa, because higher values can harm root growth. The initially high level of soil compaction in some direct sowing systems might suggest that the impact of subsequent traffic would be minimal, but data have not been consistent. In the other hand on freshly tilled soils, traffic causes significant increments in soil compaction. The aim of this paper was to quantify the interaction of the soil cone index and rut depth induced by traffic of two different weight tractors in two soil conditions: a) soil with seven years under direct sowing system b) soil historically worked in conventional tillage system. Treatments included four different traffic frequencies (0, 1, 6and 8 passes repeatedly on the same track). The work was performed in the North of the Rolling Pampa region, Buenos Aires State, Argentina at 33o 21’ S, 62o 15’ W, altitude 12 m above sea level.Variables measured were: (1) cone index in the 0 to 600 mm depth profile and (2) rut depth. The tire sizes and the rut depth and rut width ratio are particularly important respect to compaction produced in the soil for different number of passes. Until six passes of tractor (FWA) ground pressure is responsible of the top soil compaction. The tire with low depth/width ratio indicated that most of the compaction occurred near the surface.(Glycine max L.) is grown mainly on clayey soils (2.6 million ha). These soils are very susceptible to heavy traffic compaction. Soil penetration resistance, in fine textured soil, should not exceed 1200 kPa, because higher values can harm root growth. The initially high level of soil compaction in some direct sowing systems might suggest that the impact of subsequent traffic would be minimal, but data have not been consistent. In the other hand on freshly tilled soils, traffic causes significant increments in soil compaction. The aim of this paper was to quantify the interaction of the soil cone index and rut depth induced by traffic of two different weight tractors in two soil conditions: a) soil with seven years under direct sowing system b) soil historically worked in conventional tillage system. Treatments included four different traffic frequencies (0, 1, 6and 8 passes repeatedly on the same track). The work was performed in the North of the Rolling Pampa region, Buenos Aires State, Argentina at 33o 21’ S, 62o 15’ W, altitude 12 m above sea level.Variables measured were: (1) cone index in the 0 to 600 mm depth profile and (2) rut depth. The tire sizes and the rut depth and rut width ratio are particularly important respect to compaction produced in the soil for different number of passes. Until six passes of tractor (FWA) ground pressure is responsible of the top soil compaction. The tire with low depth/width ratio indicated that most of the compaction occurred near the surface.