Biodiversification in intensified agricultural systems: soil health responses and provision of ecosystem services

• Ano de defesa: 2026
• Autor(a) principal: Carvalho, Martha Lustosa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertacoes da USP; Universidade de São Paulo; Escola Superior de Agricultura Luiz de Queiroz
• Palavras-chave em Português: Adicionalidade; Multifuncionalidade do solo; Mitigação de gases de efeito estufa; Manejo ecológico do solo; Agricultura regenerativa; Management additionality; Greenhouse gas mitigation; Ecological soil management; Regenerative agriculture; Soil multifunctionality
• Link de acesso: https://teses.usp.br/teses/disponiveis/11/11140/tde-08052026-160055/

This thesis investigates how biodiversification influences soil health and the provision of ecosystem services in tropical and subtropical Brazilian agroecosystems. Through a systematic literature review, we first demonstrate that multispecies cover crop mixtures significantly increase dry matter production (0.33 to 17.9 Mg ha^{<small>-1</small>}) and nutrient uptake (up to 121, 14, and 131 kg ha^{<small>-1</small>} of N, P, and K, respectively) compared to monocultures. These diverse inputs are critical for climate mitigation, as biological nitrogen fixation by Fabaceae can reduce the need for external N inputs. In consolidated no-till systems with relatively high soil health baselines, we found that conventional indicators (e.g., soil organic carbon and aggregate stability) showed limited short-term sensitivity to diversification. In contrast, biologically mediated indicators, such as active carbon, were more responsive and better captured management additionality, with increases of 23.9% and 26.7% for crop rotation and cover crops, respectively. When evaluated using the Soil Health Assessment Protocol and Evaluation (SHAPE), these indicators enabled an integrated interpretation of soil health by accounting for inherent soil and climate properties, revealing functional differences between systems that are not captured by isolated indicators. Furthermore, diversification increased system climate efficiency and reduced greenhouse gas emission intensity, with reductions of 21% for crop rotation in both evaluated years and 37% and 40% for cover crops in years one and two, respectively. However, these benefits were sensitive to interannual climate variability; El Niño-induced soil saturation triggered episodic surges in CH_{<small>4</small>} and N_{<small>2</small>}O emissions, resulting in a 66.3% increase in emissions in the year under its influence. Collectively, these findings highlight that in conservation systems with already relatively high soil health scores, monitoring should prioritize sensitive and functionally relevant indicators, along with tiered assessment protocols, to accurately and cost-effectively capture long-term soil restoration.