The aim of this study was to evaluate the use of biochar (produced by slow pyrolysis of Eucalyptus grandis biomass) as bulking agent for the composting of poultry manure. Three composting mixtures were prepared by the turned-pile system by mixing poultry manure with different organic wastes used as bulking agent (biochar, coffee husk and sawdust) in a proportion of 1:1 (fresh weight). Despite the inert nature of biochar, the composting mixture prepared with biochar underwent an organic matter degradation of 70% of the initial content. The organic matter of the poultry manure-biochar mixture was characterised by a high polymerisation degree of the humic-like substances, with a relative high proportion of humic acids in relation to fulvic acids. At the end of the composting process, the humic acid fraction represented more than 90% of the alkali extractable fraction, reflecting the intense humification of this material. Enrichment of poultry manure with biochar reduced the losses of nitrogen in the mature composts, although the use of sawdust would be more efficient in preserving the organic matter and nitrogen in the mature compost.

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The use of native forests for the purpose of agricultural and livestock occupation have caused the degradation of native ecosystems of caatinga and cerrado. The negative impact of these activities can be minimized with the revegetation of degraded areas. With that comes the need to produce seedlings of native forest species of quality. The objective of this study was to evaluate how the addition of bagana of carnaúba, compost, and cattle manure to Quartzarenic Neosol soil affects the percentage and rate of emergence, growth, and macronutrient contents of Hymenaea stigonocarpa Mart (Jatobá) seedlings. The treatments consisted of the following proportions (v/v) of bagana of carnaúba, compost,

ResumoAs macrófitas aquáticas são muito utilizadas como bioindicadoras de qualidade da água, pois sua proliferação ocorre geralmente em mananciais eutrofizados e tem atingido diversas partes do Brasil e do mundo, restringido os usos múltiplos de ecossistemas aquáticos. Contudo, esse grupo de plantas é capaz de reter considerável quantidade de nutrientes, apresentando alta produtividade e alta taxa de crescimento, constituindo assim uma boa fonte de biomassa vegetal para ser utilizada na produção de substratos. Com o objetivo de avaliar o potencial das macrófitas aquáticas aguapé (Eichhornia crassipes Solms.), alface d'água (Pistia stratiotes L.) e taboa (Typha domingensis Pers.) na produção de substratos, foi realizado, neste trabalho, sua caracterização física e química e avaliação do grau de humificação. Os tratamentos foram dispostos em esquema fatorial 3 × 4, delineamento inteiramente casualizado com 3 repetições. Todos os substratos produzidos com 100% macrófita apresentam densidade dentro do limite de 400 kg m -3 considerado ideal. Os substratos compostos com alface d'água e aguapé encontram-se com condutividade elétrica de 0,79 a 2,49 dS m -1 , dentro do recomendado. Os compostos orgânicos produzidos são considerados maduros e apresentam elevados teores de nitrogênio fósforo e potássio; O substrato produzido com 70%alface d'água+30%esterco e os compostos por 70%taboa+20%esterco+10terra vegetal e 70%taboa+30%esterco apresentam relação C/N dentro do considerado ideal; A razão de humificação e índice de humificação, exceto para os tratamentos 4 (70%alface d'água+30% esterco), 5 (100%aguapé) e 8 (70%aguapé+30% esterco) encontram-se dentro do considerado ideal, a porcentagem de ácidos húmicos e índice de polimerização, exceto nos tratamentos 1(100%alface d'água) e 12 (100%taboa), apresentam-se abaixo do ideal. Palavras-chave: Eichhornia crassipes, Pistia stratiotes, Typha domingensis AbstractAquatic macrophytes are widely used as bioindicators of water quality because their proliferation usually occurs in eutrophic water sources and has hit several parts of Brazil and the world, restricted the multiple uses of aquatic ecosystems. However, this group of plants is able to retain considerable amounts

The use of the system, handling and time adoption of these can effectively alter the quantity of organic matter (OM) and change the cycling of nutrients in the soil. This paper aimed at evaluating the availability of nutrients and OM contents in an Oxisol (Xanthic Ferralsol) located within a Cerrado area (Savannah ecosystem) of the Piauí State in Brazil, after years under different soil use and management systems. The treatments consisted of soils under no-tillage for three, six and nine years (NTS3, NTS6, and NTS9); pasture for two and six years (PA2 and PA6, respectively); eucalyptus plantation for six and 12 years (EU6 and EU12); conventional tillage system for two and eight years (CTS2 and CTS8) and native Cerrado (NC), which represented conditions of equilibrium. For each area, we assessed the levels of OM, pH in water, Al Use and management systems provided significant effects on the availability of soil macronutrients and OM contents, but have inadequate levels of micronutrients in the soil, especially Boron. In areas under tillage, there is an increase in pH, availability of nutrients and OM in the surface layer, especially during the first six years of adoption of the system, while in the areas with nine years; there were an increase in P levels in subsurface. The areas under cultivation with eucalyptus show higher potential in increasing the OM levels in soil subsurface layers. , em quatro profundidades do solo (0-10, 10-20, 20-30 e 30-40 cm) e teores de Cu, Mn, Zn, Fe, B e S, na profundidade de 0-40 cm, todos com quatro repetições. Os sistemas de uso e manejo proporcionaram efeitos significativos na disponibilidade de macronutrientes no solo e nos teores de MO, mas apresentam níveis inadequados de micronutrientes no solo, especialmente boro. Nas áreas de plantio direto, há aumento de pH, disponibilidade de nutrientes e MO na camada superficial, especialmente nos primeiros seis anos de adoção do sistema, enquanto nas áreas com nove anos, houve um aumento nos níveis de P em subsuperfície. As áreas cultivadas com eucalipto apresentam maior potencial de aumento dos teores de MO nas camadas subsuperficiais do solo.Palavras-chave: toxicidade de alumínio; propriedades químicas; fertilidade do solo