Measuring differences in soil properties in soils with different cultivation practices using computer tomography

Abstract A change in tillage practice from mouldboard ploughing to reduced tillage with a rotavator is suggested to reduce problems with soil erosion in Norwegian soils. The long-term effects on soil properties by this change have to be investigated in order to maintain agricultural production and avoid new negative side effects on the environment. In this investigation, soil with 4entional tillage practice was compared to soil with reduced tillage using computer tomography (CT). The advantage of CT is that it nondestructively provides a spatial density distribution. The macropores are effectively separated from the soil matrix with micropores. It was found that soil with conventional tillage had a loose structure with a wide range of densities in the ploughing layer. Below the ploughing depth the soil was compact with very little macropores. The soil with reduced tillage had a nearly uniform density profile, but macroporosity in the subsoil was significantly larger than near the surface. Computer tomography is a useful tool for nondestructively measuring bulk density and macroporsity. The effect of an increased number of macropores on solute infiltration was also visualised using CT.