Structural changes in a silt loam under long-term conventional or minimum tillage

Abstract

The effects of conventional tillage (CT) and minimum tillage (MT) on the stability of soil aggregates, pore-size distribution, bulk density, infiltration and penetration resistance were assessed after more than 10 years of crop production at a silt loam soil in Canterbury, New Zealand. Results show that a detrimental decrease in the aggregate stability occurred if the soil was cultivated annually. Conventional tillage slightly increased total and macro-porosity at the cultivated depth. Below this depth, however, this practice resulted in soil compaction as indicated by lower soil porosity, higher bulk density and higher penetration resistance than those under MT. No significant differences were found in the infiltration rate.