The soils of the Brazilian Savanna are generally acidic and have low availability of nutrients, so the use of alternative inputs to improve their fertility should be investigated. The objectives of this study were to evaluate the potential of biochars from rice husk (BHR) and from bovine manure (BCM) in increasing phosphorus availability and their effects on soil chemical properties and in common beans plants. The experiments were carried out in a completely randomized design, in a 4x2+3 factorial scheme with four replicates. The treatments were four biochar doses (1, 2, 3 and 4% m/v), two biochars (BRH and BCM) and three additional treatments (C1, no liming and no fertilization; C2, addition of Ca and Mg carbonate and NPK fertilizers and; C3, addition of Ca and Mg silicate and NK fertilizers). In the highest doses of BRH there was an increase of 2.7, 5.3 and 2.5 times in the P content extracted by Mehlich 1 and quantified by colorimentria, by Mehlich 1 and quantified by spectroscopy and by ion exchange resin and quantified by spectroscopy, respectively. For the highest doses of BCM, the increases in P content were 51.3, 289.2 and 88.4 times greater than in C1, respectively, according to the methods described for BRH. The biochars increased soil pH, CEC, nutrient content and the growth of bean plants compared to C1, especially BCM. However, the production of dry matter was significantly lower than that obtained in C2.

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.

O uso de substratos empregando o biochar como componente consiste de uma alternativa viável na produção de mudas florestais, devido às melhorias nas suas características físico-químicas. Diante do exposto, o objetivo deste trabalho foi avaliar o efeito do tamanho de partícula e da proporção de biochar de casca de Caryocar brasiliensis sobre a produção de mudas de Eucalyptus urophylla. O biochar foi empregado em quatro granulometrias (>0,5; 0,5-1,0; 1,0-2,0; 2,0-4,0 mm), misturados ao substrato comercial @bioplant (turfa de Sphagnum, fibra de Coco, casca de arroz, casca de pinus e vermiculita) em cinco proporções: 0, 25, 50, 75%, 100% (v/v). Avaliou-se as propriedades físicas, densidade de partícula, densidade aparente e porosidade dos substratos testados. Já o desenvolvimento fisiológico da muda foi analisado através das variáveis: porcentagem de germinação, índice de velocidade de emergência, altura, diâmetro de colo, relação altura / diâmetro de colo, comprimento de raiz pivotante, massa seca da raiz e massa seca aérea aos 120 dias, correlacionando com as características físicas e químicas do biochar utilizado. A adição do biochar em menores proporções (< 25%) com o substrato comercial, confere ao substrato melhorias nos atributos físico-químicos, como o aumento da porosidade. Conclui-se que os melhores resultados fisiológicos para a espécie em estudo foram obtidos utilizando granulometrias de biochar entre 1 e 4 mm independente da proporção e biochar aplicada.

Brazil is the world’s largest producer of charcoal. Therefore, there is need for improvement in the gravimetric yield of conversion and the reduction of gas emissions, including greenhouse gases (GHGs), released during carbonization. The objective was to apply the methodology of Measurement, Reporting and Verification (MRV) to evaluate the emission of GHG, mainly CO₂ and CH₄. The charcoal production kiln-furnace system used was composed of 4 kilns with a capacity of ~6 t of wood, each. The MRV cluster of coal gravimetric yield and gas burners were used to determine the gravimetric yield and burner efficiency and thus evaluate the emission of GHGs generated in the carbonization system. The carbonization was performed in an isolated way producing, in total, 3.34 t of charcoal, with an average gravimetric yield of 25.82%. The MRV methodology was effective for evaluating the GHG emissions. The wood burner reduced by 50% the methane burning and provided a reduction of 0.392 tCO₂ eq (23.91%). The humidity of wood and high precipitation were the main limiting factors in this research, and responsible for the decrease in the gravimetric yield. The kiln-furnace system was effective for a sustainable production with the use of non-continuous carbonization gas burners.

In recent years there has been a growing interest in the use of organic waste in agriculture. In this way, was aimed with this study to evaluate the biochar from pequi shell (Caryocar brasiliense Cambess) on the soil chemical properties and on the production and nutrition of common bean plants. The experiment was carried out in pots with soil (4 dm3 ~ 5,44 kg), in a completely randomized experimental design, 4 x 3 + 2 factorial scheme, with four replications. The treatments were four doses of biochar (0.0, 2.5, 5.0, 7.5 and 10.0 % v/v), three different particle size (G1, <0.5 mm; G2, 0.5-1,0 mm and G3, 1.0-2.0 mm) and two control treatments, one without and another with addition of soil corrective acidity. The biochar from pequi shell acted as a corrective of soil acidity and as a source of potassium for the plants. However, in higher doses of biochar there was a decrease in bean plants production due to nutritional imbalances.