How does tillage intensity affect soil organic carbon? A systematic review protocol

摘要: Soils contain the greatest terrestrial carbon (C) pool on planet. Since approximately 12 % of soil C is held in cultivated soils, management these agricultural areas has a huge potential to affect global cycling; acting sometimes as sink but also source. Tillage one most important practices for and been traditionally undertaken mechanically prepare soils seeding minimize effects weeds. It associated with many negative impacts quality, notably reduction organic (SOC), although still matter considerable debate, depending factors such depth measurement, type, tillage method. No or reduced intensity are frequently proposed mitigation measures preservation SOC improvement example reducing erosion. Whilst several reviews have demonstrated benefits conservation no till agriculture over intensive tillage, general picture unclear. This systematic review proposes synthesise an extensive body evidence, previously identified through map. based studies concerning collated recently completed map impact restricted warm temperate climate zone (i.e. boreo-temperate). These 311 were selected systematically according CEE guidelines. An update original search will be identify newly published academic grey literature time since was performed September 2013. Studies critically appraised their internal external validity, followed by full data extraction (meta-data describing study settings quantitative results). Where possible, included meta-analyses examining effect (‘moderate’ shallow) relative ‘intensive’ methods mouldboard ploughing, where turned throughout profile). The implications findings discussed terms policy, practice research along discussion nature evidence base.