Résumé
A global meta-analysis identifies the key predictors of compost on crop yield, soil organic carbon and nitrous oxide emissions. The proposed precision compost strategy has the technological potential to increase the production of major cereal crops by 4% and restore 26.5% of current topsoil soil organic carbon stocks on a global scale.
Compost represents an important input for sustainable agriculture, but the use of diverse compost types causes uncertain outcomes. Here we performed a global meta-analysis with over 2,000 observations to determine whether a precision compost strategy (PCS) that aligns suitable composts and application methods with target crops and growth environments can advance sustainable food production. Eleven key predictors of compost (carbon-to-nutrient ratios, pH and salt content electric conductivity), management (nitrogen N supply) and biophysical settings (crop type, soil texture, soil organic carbon, pH, temperature and rainfall) determined 80% of the effect on crop yield, soil organic carbon and nitrous oxide emissions. The benefits of a PCS are more pronounced in drier and warmer climates and soils with acidic pH and sandy or clay texture, achieving up to 40% higher crop yield than conventional practices. Using a data-driven approach, we estimate that a global PCS can increase the production of major cereal crops by 96.3 Tg annually, which is 4% of current production. A global PCS has the technological potential to restore 19.5 Pg carbon in cropland topsoil (0-20 cm), equivalent to 26.5% of current topsoil soil organic carbon stocks. Together, this points to a central role of PCS in current and emerging agriculture.