Changes in the physical properties of soils under conventional and no-Tillage practices in temperate regions and simulations using selected agroecosystem models

Abstract

No-Tillage (NT) systems are currently recommended because they are assumed to support more ecosystem services than conventional tillage (CT) systems. Although no-Till systems have shown long-Term success in agriculture in subtropical regions, no clear evidence of NT-driven improvements in soil properties and crop growth conditions has been put forth in temperate climates. The current study summarizes the findings of 26 previously published studies, in which the authors compared 76 experimental sites in temperate regions to represent changes in soil bulk density (BD) and soil organic carbon (SOC) contents under tillage practices. The studies were grouped by soil texture and experiment duration, and the results were tested for significant changes under NT relative to CT. Statistically significant differences in SOC were found for loamic soils, and differences in BD were found for siltic soils. For loamic soils, the average increase in the carbon (C) concentration was 0.16%, which corresponded to a C stock increase of 6.48 Mg C/ha and increase of BD for siltic soil 0.01 Mg/m3in NT system. Two agroecosystem models, HERMES2Go and MONICA, were tested for their sensitivity in simulating these differences in SOC between NT and CT systems. In a 60-year simulation, the HERMES2Go model predicted a C stock loss of 0.31 Mg C/ha under NT for loamic soils, whereas the MONICA model predicted a gain of 0.53 Mg C/ha. At present, neither model can effectively reproduce the increase in SOC content observed under NT in experiments.