Abstract Non-Technical Summary Agriculture is the single largest cause for transgressing planetary boundaries. A global transformation to sustainable intensification is required in order to hold the windows open for meeting the Paris climate accord of limiting global warming to 1.5°C and the global biodiversity framework of halting loss of biodiversity, while securing food for a growing world population. Conservation Agriculture (CA) offers the only universally applicable agricultural practices that can be adopted at scale and speed, i.e., across all agro-ecological zones within the coming 1–2 decades. We review the rationale, evolution, and prospects of CA across the world. Technical summary We estimate that CA has almost doubled from approximately 100 to 200 M ha between 2008/09 and 2018/19, covering approximately 15% of global cropland. Our projections until 2024, estimates another 30% increase (to 250–270 M ha), with a potential of expanding to 50% of global cropland area by 2050 (≈700 M ha). CA includes three fundamental principles; zero-tillage, cover crops, and diverse crop rotations. Converting from conventional tillage-based ploughing to CA sequesters ∼0.1–2 t C ha −1 yr −1 . Considering an average sequestration potential with CA of 0.5–0.9 t carbon ha −1 y −1 , converting the total 1.5 billion ha of global cropland to CA could sequester 0.41–0.82 billion t of carbon ha −1 y −1 . Additionally, CA reduces pressure on biodiversity, increases soil moisture holding capacity, builds resilience of plant production to extremes, and reduces fuel use for tillage by 50–70 %. CA has proven to maintain, stabilize, and increase high yield levels in intensive agricultural systems, which currently are stagnating or even decreasing in tillage-based agricultural systems, while significantly increasing yield levels on relatively poor or degraded agricultural soils. While CA is not a panacea for all food production challenges, it is difficult to find a more ready-to-scale farm practice. Multi Media Summary Conservation Agriculture offers a universally applicable agricultural practices that can be adopted at scale and speed.
Rockström et al. (Thu,) studied this question.