Carbon Stocks in Mined Area Reclaimed by Leguminous Trees and Sludge

Abstract

-Few studies have been carried out on aboveground (or belowground) and soil/substrate C accumulation in severely degraded areas, such as mined areas. The present study was developed in order to find a recovery strategy for a mined area and characterize its potential for C sequestration by planting two nitrogen-fixing Brazilian tree species (Mimosa caesalpiniifolia Benth and M. bimucronata (DC.) O. Kuntze). Sewage sludge was included in the experimental design. An experiment under randomized block condition and 2 x 5 factorial design with four replications were defined and carried out, in Rio de Janeiro State, Brazil. The treatments consisted of a combination of both tree species and five sewage sludge doses (0, 2.85; 5.70; ). M. caesalpiniifolia grows better (p<0.05) in reclaimed areas than M. bimucronata, even though neither the height nor the basal area of both species responded to the sludge application. Carbon stock in the tree trunks differ between species (27.3 and 14.3 Mg ha -1 , for M. caesalpinifolia and M. bimucronata, respectively), and was influenced by the doses of sewage sludge, whereas the soil carbon stock (0-10 cm) did not differ between species and doses (12.0 and 12.2 Mg ha -1 , for M. caesalpiniifolia and M. bimucronata, respectively). Soil fertility in the degraded site was found to be improved by legume trees six years after planting, with a small influence of the sewage sludge level. Mined areas recovered with legume trees can sequestrate significant amounts of C both in aboveground biomass and soil in a short period of time.Keywords: Soil carbon and nutrients accretion; Reclamation of soil; Aboveground biomass accumulation. (0, 2,85; 5,70; 11,40 e 22, ESTOQUE DE CARBONO EM ÁREAS DE MINERAÇÃO RECUPERADA COM LEGUMINOSAS ARBÓREAS E LODO RESUMO -Poucos estudos foram conduzidos em relação à acumulação de C na parte aérea (ou subterrânea) e solo/substrato em áreas severamente degradadas, como áreas mineradas. O presente estudo foi desenvolvido para encontrar uma estratégia de recuperação para uma área minerada e caracterizar o seu potencial de sequestro de C a partir do plantio de duas espécies de árvores brasileiras que fixam nitrogênio do ar (Mimosa caesalpiniifolia Benth e M. bimucronata (DC) O. Kuntze). Lodo de esgoto foi incluído no desenho experimental. Assim, um experimento em delineamento em blocos ao acaso e esquema fatorial 2 x 5 e quatro repetições foi instalado no estado do Rio de Janeiro, Brasil. Os tratamentos consistiram em uma combinação de duas espécies arbóreas e cinco doses de lodo de esgoto

Ecological indices of phytophagous Hemiptera and their natural enemies on Acacia auriculiformis (Fabales: Fabaceae) plants with or without dehydrated sewage sludge application in a degraded area

“…In this context, species of the genus Acacia (Fabales: Fabaceae) may be useful due to their rapid growth and the capacity for biological nitrogen fixation (BNF) in association with symbiotic bacteria [5]. The natural introduction of nitrogen can intensify the cycle of other nutrients and stabilize soil organic matter in degraded environments [6]. Among the species of this genus, Acacia auriculiformis A. Cunn.…”

Effects of the planting of legume species and soil conditions on the recovery of a sand and pebble mining area

“…Balieiro et al (2017) developed a study testing the use of legume species with increasing doses of sewage sludge as organic material and observed an increase in the fertility of the degraded soil with the green manure treatments, despite having observed a significant difference only for the available phosphorus values. These results also corroborate the idea of using legume species with organic matter maintenance for the soil recovery processes.…”

“…Such competition causes the leaching of these basic cations (Tavares, Valadão, Weber, & Espinosa, 2019), which highlights the relevance of understanding the effect of using green manures and the management of soil degraded by mining, in order to ensure success in restoration projects. Balieiro et al (2017) developed a study testing the use of legume species with increasing doses of sewage sludge as organic material and observed an increase in the fertility of the degraded soil with the green manure treatments, despite having observed a significant difference only for the available phosphorus values. These results also corroborate the idea of using legume species with organic matter maintenance for the soil recovery processes.…”

Percentage of importance indice-production unknown: loss and solution sources identification on system

“…Acacia spp. (Fabales: Fabaceae) are used to recover degraded areas (Balieiro et al, 2017), although the introduction of non-native plants may impact natural ecosystems. The abiotic characteristics of the area and the life history facilitate the establishment and dispersal of mangium tree, Acacia mangium Willd.…”