No-till systems: gains and drawbacks for carbon sequestration, ecosystem services and environmental health

摘要

Changes in land use from native woodlands, shrub-lands or grasslands to agricultural lands have generated considerable modifications in hydrological systems, biodiversity and nutrient cycling . The conversion from natural lands to croplands has also had a detrimental effect on soil quality and functioning, specifically through the breakdown of macro-aggregates and the increased decomposition rates of soil organic carbon (SOC). First and foremost, these changes are attributed to tillage action, which leads to deformation of soil structure and exposes the previously protected SOC to oxidation. Also, excluding crop residues from the field decreases the replenishment of organic matter back into the system . Because SOC determines soil quality and fertility as well as regulates a range of related ecosystem services, the diminished SOC pools result in both onsite and offsite degradation processes .