Banca de DEFESA: PAULO MOUTINHO ANDRADE DE SOUZA

NUTRIENTS IN AGROFORESTRY GARDENS

homegarden, nutrients, agroforestry system, soil

Throughout millennia, agriculture has undergone significant changes, with the Green Revolution being a phase that, despite promoting advancements, introduced environmentally harmful practices such as intensive monocultures and pesticides. In the pursuit of sustainable alternatives, researchers have turned their attention to agroforestry systems (AFS), which integrate agricultural and forest plants to promote environmental and social benefits. The literature highlights the lack of specific studies on agroforestry home gardens. Agroforestry home gardens, managed by family farmers and indigenous peoples, stand out as sustainable models that can also meet nutritional and economic needs. In addition to practical benefits, there is cultural and social relevance in agroforestry practices, as ancestral knowledge is recognized and mobilized, the role of women in managing agroforestry systems is valued, and income is generated for local communities. Despite their importance, the scarcity of research on agroforestry home gardens limits knowledge about them and public policy support for their promotion. Case studies indicate that these home gardens can enrich the soil, contributing to the fertility and productivity of the agroecosystem. Therefore, more comprehensive ecological research is needed to understand nutrient availability in these systems. In light of this need, the study's objective is to systematically review the available knowledge in the scientific literature on nutrient availability in agroforestry home garden soils. The study employed systematic review as a rigorous method preserving essential elements of a systematic review while adjusting procedures for a less extensive study. Google Scholar, Scielo, Scopus, and Web of Science were used for literature review, with searches conducted in Portuguese, Spanish, and English from 1992 to 2023. Specific keyword combinations were used to filter articles, theses, and dissertations on chemical analysis, cycling, and nutrient availability in agroforestry home gardens. Data analysis involved coding and categorizing the selected works to extract broad themes that facilitated the construction of a systematic understanding of nutrient availability and transfer in the soils of these home gardens, based on the available knowledge in the scientific literature. Seventeen documents were examined, generating 329 analysis records and 27 codes. Key themes included carbon availability (11.5%), water (6.6%), and phosphorus (9.5%). The studies covered home gardens in Brazil, India, Bangladesh, Peru, and Ethiopia. Based on the results of the systematic review conducted in this study, it can be concluded that agroforestry home gardens, especially in tropical environments, can positively impact nutrient availability in the soil, such as phosphorus, potassium, carbon, and nitrogen. Furthermore, the results demonstrate how the presence of organic matter and agroforestry management are crucial, especially in acidic soils, and that nutrients tend to concentrate in surface layers, influenced by various factors beyond management, such as the presence of aluminum, acidity, rainfall, and altitude. This study is important for understanding the nutrients available in agroforestry home garden soils and the mechanisms of nutrient availability.