An investigation into the effect of traffic and tillage on soil properties using X-ray computed tomography

摘要

Compaction of soils from agricultural machinery alters soil aggregate and pore structure whilst increasing bulk density. This leads to decreased soil aeration and water and nutrient uptake and increases root penetration resistance that can result in reduced crop yields. A randomised 3x3 factorial traffic (Random Traffic Farming, Controlled Traffic Farming and Low Ground Pressure systems) and tillage (Deep, 250mm; Shallow, 100mm and No-till) field experiment at Harper Adams University, UK, was setup in 2011. An investigation was conducted in 2016 using X-ray Computed Tomography (CT) to assess the effects of tillage and traffic on the soil pore size and distribution. The study highlighted that deep tillage reduces the ability of soil to support vehicular traffic which leads to soil recompaction. Deep tillage caused soil percentage porosity to decrease with depth with corresponding increases in the frequency of smaller size pores. Shallow tillage treatments increased the percentage porosity with depthwhilst providing the lowest penetration resistance. Percentage porosity is higher in untrafficked treatments. Further investigation is required to investigate the effect that the complex interactions between soil pore structure and developing root architecture have on crop yield.