Melhorando a função SOIL SPONGE para se adaptar às mudanças climáticas – quantificando sinergias e compensações agroecologia-biochar para combater de forma sustentável a desertificação

In 2022, the Commission included biochar in the Fertilising Products Regulation, which has opened the Single Market to biochar and other organic and waste-based fertilisers. According to the IPCC report on Climate and Land: “Biochar could make a significant contribution to mitigating both land degradation and climate change, simultaneously” and “Biochar is a land-management technique of high potential, but controversial”. SOILSPONGE aims to quantify the contributions, specifically those relevant for combating desertification, and SOILSPONGE aims to reduce the controversy by monitoring the sponge function at the slope scale to improve accuracy of models at the catchment scale. Regarding the research challenge, i.e. the knowledge gap, please see the “WHY?” part of the previous section (“descrição). The necessity of combining biochar application with soil bunds and deeper rooting plant species was also a conclusion of a review paper on the topic: “integrating physical soil and water conservation practices with agronomic soil and water conservation practices are essential to increase both provisioning and regulating ecosystem services” (Adimassu et al., 2017). SOILSPONGE’s main innovative aspect is the spatiotemporal upscaling of biochar’s effect on the soil sponge function COMBINED with soil bunds and deeper rooting perennials. This 3-pronged synergy (biochar+bunds+deeper rooting) can be regarded as the maximum potential improvement of the soil sponge function in rainfed pastures in Portugal, in a sustainable way, i.e. without negative effects on soil health – uniquely enabled by the broad experience of the PI and team and the strategic partnerships within Portugal and internationally. SOILSPONGE will develop novel C and water scarcity footprint methods, apply SWAT and LISEM models to account for increased water storage in the rooting zone achieved by biochar incorporation into soils, and scale up by applying large-scale land surface modelling. The attached “SOILSPONGE Methodology” pdf shows the relation between, and the related methods of, the 5 main questions of the 3 experimental tasks: 2. How can soil bunds be designed to optimize water infiltration without disrupting farming operations? 3a. How does biochar incorporation affect slope hydrology? 3b. How does biochar incorporation + soil bunds affect slope hydrology? 3c. How does biochar and biochar+bunds affect soil and crop health? 3d. How do cows and soil biota affect the soil sponge function? 4. Can we integrate and upscale the data? The research objectives/questions are ambitious and innovative. At the time of writing, there were no publications on combining soil bunds with biochar for any land use, let alone rainfed pastures. Installing and monitoring slope-scale plots in a robust way is an ambitious undertaking. The ”monitoring” slides in the attached “SOILSPONGE Methodology” pdf provide a visual overview of how we propose to manage this challenge, i.e. by monitoring soil moisture content (and temperature) throughout the whole soil profile (groundwater recharge, ET) at upslope, midslope and downslope positions (every 30 minutes), and by considering spatial heterogeneity in soil health monitoring. Adimassu et al., Environmental Management (2017) 59:87–101 DOI 10.1007/s00267-016-0776-1