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Feedstock and pyrolysis conditions of biochars
Publication . Coelho, L.; Canedo, J. N. G. V.; Custódio, M.; Flores, D.; Mourão, P.; Palma, P.; Prats, S. A.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Elsevier Science B.V., Amsterdam.
The use of biochar for soil restoration requires understanding ecological trade-offs, particularly how feedstock selection, dose, and production methods influence soil and aquatic ecotoxicity. The ecotoxicological effects of nine biochars derived from vineyard residues, Acacia wood, and olive pomace were evaluated after mixing them at rates of 1.5–5 % into two agricultural soils. Additionally, specific details of the biochar production method were assessed: blending ratios (vine pruning:stalks), pyrolysis temperature, (for Acacia wood) and hydrothermal activation method (for olive pomace). Physicochemical characterization—pH, electrical conductivity, organic matter, carbon and nitrogen content, polycyclic aromatic hydrocarbons (PAHs), FTIR spectroscopy and inertinite content—was combined with ecotoxicological assessment (Lactuca sativa L. phytotoxicity test and aquatic lethal and sub-lethal bioassays with Daphnia magna and Thamnocephalus platyurus). Vineyard pruning and shredded Acacia biochars, which had higher OM contents and lower EC and PAH concentrations, showed the lowest toxicity in soils and aqueous extracts. Soil mixed with biochar at 3–5 % blends optimally restored acidic soils through pH neutralization and moisture retention, which favoured seed growth. The aquatic assays showed stimulatory effects on D. magna feeding rates, increasing by 20–90 % at 5 % biochar concentration. Finally, production assessment revealed that both blending ratios and pyrolysis temperature caused minimal variability in organisms' responses. Hydrothermal activation reduced PAH content (<0.08 mg kg−1) but failed to reduce salinity-driven ecotoxicity. These results suggest that 3–5 % wood-derived biochars are suitable to restore soils without risk to aquatic ecosystems. Olive pomace and vine stalk alternatives need a pre-application screening to detect PAHs and salinity conditions, essential factors affecting physicochemical properties of agricultural soils and environmental safety.
Partial replacement of concentrate in the lactating ewe's diet with silages of agro-industrial by-products
Publication . Jerónimo, Eliana; Cachucho, Liliana; Alves, Helder; Guerreiro, Olinda; Paulos, Kátia; Costa, Cláudia; Costa, João; Gomes, Sandra; Alvarenga, Nuno; Alves, Susana P.; Bessa, Rui J. B.; Santos-Silva, José; Dentinho, Maria Teresa P.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Elsevier BV
The purpose of this experiment was to evaluate the effect of partial replacement of concentrate feed with mixed ingredient silages (MIS) produced with agro-industrial by-products in the diets of lactating ewes on the body weight of ewes, growth performance of suckling lambs, composition and fatty acid (FA) profile of milk, and serum metabolites of the ewe. After lambing, 54 lactating ewes and their lambs were distributed to one of the following experimental diets (18 ewes/diet): C – concentrate diet; SPBG – concentrate and silage containing 200 g/kg sweet potato, 500 g/kg brewers grains and 300 g/kg alfalfa hay; and AHBG – concentrate and silage containing 200 g/kg almond hulls, 600 g/kg brewers grains and 200 g/kg alfalfa hay. Hay was provided ad libitum in all diets. In both silage diets (SPBG and AHBG) the concentrate and silage constitute 33.3 and 66.6 % DM of the diet, respectively. Every day, the ewes received the same amount of the diet, which was completely consumed. Lambs were weighed at birth and weekly during the 8 weeks of trial. In the last 4 weeks of the trial, individual milk samples were collected weekly and then pooled per each ewe for chemical analysis. At the end of the trial, a blood sample was collected from the ewes to analyse serum metabolites. SPBG and AHBG silage showed pH values of 4.00 and 4.29, respectively. Total N as NH3-N and as soluble-N varied from 3.23 to 5.23 and from 348 to 354 g/kg total N, respectively. The animals well accepted the silages. Partial replacement of concentrate with silage of agro-industrial by-products in lactating ewe diets did not affect the growth performance of suckling lambs and the composition of milk. Both silage dietary treatments changed the milk FA composition, reducing the short-chain FA (6:0–14:0), branched-chain FA, and 18:1 trans-10, and increasing the saturated FA 16:0, 18:0, 20:0, 22:0, 23:0 and 24:0 and 18:1 trans-11. Regarding serum metabolites, silage diets increased the urea concentration and decreased the β-hydroxybutyrate concentration. Results showed that ensiling is a good approach to preserving sweet potato, almond hulls, and brewers grains, producing a good quality feed that can be introduced to diets of lactating ewes without compromising animal performance.
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Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017/2018) - Financiamento Programático
Número da atribuição
UIDP/05183/2020