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To date, the potential of land management for climate change mitigation has primarily been evaluated with a focus on soil organic carbon sequestration or greenhouse gas emissions. However, land management practices can also achieve climate change mitigation through biogeophysical effects, such as changes in the local energy budget owing to modifications in surface albedo (that is, the fraction of incoming sunlight reflected back to space from the surface of the Earth and thus not absorbed and trans-formed into heat), or changes in evapotran-spiration that represents an export of latent heat. To obtain a picture of the biophysical effects of conservation agriculture on cli-mate change mitigation, surface albedo and heat fluxes must be quantified.Four-component net radiometers can be used to monitor incoming and outgoing shortwave (albedo) and longwave (heat flux) radiation. This instrument consists of a pair of pyranometers and a pair of pyrgeom-eters, with one of each pair facing upwards and the other one facing downwards. A pyranometer measures the ratio of reflected versus incoming shortwave solar radiation (0.3–2.8 µm) to enable the calculation of surface albedo. The pyrgeometer measures longwave radiation (4.5–50 µm), either emitted as infrared radiation or converted as sensible or latent heat flux, and allows the calculation of the amount of thermal energy stored or lost by the surface.Albedo and heat flux measurements can quantify the effect of various conserva-tion agricultural practices on the local energy budget. Preliminary results show that mulching with crop residues on clayey soils can increase albedo, leading to a local cooling effect. However, on light-coloured sandy soils, this approach could have the opposite effect. This result shows that land management approaches can alter the local heat budget, which — depending on the soil type — can either offset or contribute to the climate change mitigation that mulching can achieve by slightly increasing the carbon stored by the soil. Four-component net radi-ometers could therefore have an important role in determining the biophysical effects, such as the change in surface albedo, of various conservation agriculture practices for climate change mitigation in specific soil types.

https://www.nature.com/articles/s43017-023-00432-x.epdf?sharing_token=FDSyLB3qYssgrX1lchqAutRgN0jAjWel9jnR3ZoTv0P_NM3renpLLzz1F5irhTWGx4x7bkWoAhn0EgXVbdLJs729PHNbcgVPfjNG8JrvZWfszlEplps0PmKYniliH5dneWwvwdUl9XyrcApUqHsgWTdHh-JkBwHDuKk0Q4NMLX4%3D