Format:
1 Online-Ressource (18 p)
Content:
Deforestation in the Amazon has resulted in large areas of depleted soils on abandoned pastures and agricultural sites that present a restoration challenge central to protecting biodiversity and ecosystem function in the region. Biochar – charcoal made from waste materials – can improve soil physical, chemical, and biological properties, but the few tropical field trials to date do not give consistent results regarding tree growth. This study presents three years of soil performance and tree growth of a secondary forest shading nontimber forest product (NTFP) plantations of Ocotea quixos (Lauraceae), Myroxylon balsamum (Fabaceae), and their mixture. Open kiln and traditional mound biochars were added at 10 t.ha-1 at two sites with contrasting soil types. Biochar additions resulted in pronounced effects on soil properties that varied over time and with depth in the soil profile. Biochar additions generally increased soil organic matter, electrical conductivity, and plant mineral nutrients (in particular K, Ca, and Mg), but there were interactive effects of NTFP treatments, and stronger responses on the poorer soil type. Biochar amendments resulted in increased tree growth, with a 29% increase in aboveground biomass (AGB) on plots amended with kiln biochar and a 23% increase in plots with mound biochar compared to controls. Tree species also varied in growth responses to biochar additions, with the largest increases observed in Jaccaranda copaia and Piptocoma discolor. Significant interactions between biochar and NTFP treatments were also seen for tree growth responses, such as Cecropia spp. Only showing increased biomass on mound biochar plots planted with Ocotea quixos. Overall, our results demonstrate a stronger effect of biochar in less favorable soil conditions, and an overriding effect of legumes in richer soils. Therefore, biochar and legumes are critical alternatives to increase ecological resilience in the Amazon Forest using NTFP
Language:
English
DOI:
10.2139/ssrn.4358515
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