Conservation agriculture reduces climate change impact of a popcorn and wheat crop rotation

difference was due to NH3 emissions, which were higher for the conservation agriculture sys- tem, which used compost in addition to mineral fertiliser, whereas the conventional agricul- ture system used only mineral fertiliser. Marine eutrophication was 7% lower for the conservation system than for the conventional system due to lower NO3 leaching because of the cover crop in the former. Land competition was 3% higher for the conservation system than for the conventional system because more land was needed to produce cover crop seeds. Cumulative energy demand was 2% higher for the conservation system than for the conven- tional system because the cover crops required more inputs (i.e. seeds, diesel, and transport of inputs). 4.4 Other beneficial effects of conservation agriculture SOC sequestration due to conservation agriculture ceases when a new equilibrium is reached, but this does not mean that its benefits cease. Under climate change, droughts are becoming increasingly frequent and severe, with negative effects on cop productivity [46]. Increase in soil organic matter can increase plant available water capacity in the root zone, and thus improve climate-resilience of soils and agroecosystems and reduce the need for irrigation [47]. More generally, an increase of SOC has been shown to increase yields of wheat and maize and reduce the need for fertilizer N [48]. Furthermore, cover crops have beneficial effects beyond their effect on SOC [10]. Due to their albedo effect, they mitigate climate change by reflecting more sunlight than most bare

soils [49, 50]. The annual albedo effect of cover crops on climate change has been estimated to Fig 5. Net climate change impact over 50 years considering greenhouse gas emissions and soil organic carbon sequestration according to three scenarios of popcorn and wheat crop rotations. See Table 2 for a description of the scenarios. https://doi.org/10.1371/journal.pone.0285586.g005 PLOS ONE Conservation agriculture reduces climate change impact of a crop rotation PLOS ONE | https://doi.org/10.1371/journal.pone.0285586 May 23, 2023 14 / 18