Biocarvão, biomassa e composto do subproduto da indústria cítrica nos atributos químicos e biológicos do solo e no crescimento de alface.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)O Brasil é um dos principais países exportadores de suco de laranja do mundo. O processamento da laranja para à obtenção do suco, gera grande quantidade de resíduos sólidos, esses resíduos podem causar problemas ambientais, sociais e econômicos, sua fácil fermentação e decomposição, exalam odor e contribuem para a proliferação de agentes patogênicos e lixiviação de nutrientes como P. O aproveitamento de resíduos da agroindústria como bioproduto rico em nutriente pode trazer contribuição significativa ao ambiente e a sustentabilidade da produção. O objetivo foi produzir e caracterizar os biocarvões, biomassa e composto do bagaço da laranja e avaliar o seu potencial em fornecer fósforo. Foi realizada a caracterização de biocarvões, biomassa, composto de bagaço da laranja, e fracionamento do fósforo destes produtos, bem como o potencial como fonte de P dos bioprodutos, utilizando a alface como planta indicadora. Foram produzidos o biocarvão (BBL) a 300; 500 e 700 ºC, biomassa (BMBL) e composto do bagaço da laranja (CBL), analisados e testados adicionando-os ao solo. O rendimento de BBL foi maior na temperatura de pirólise de 300 ºC e menor a 700 ºC. Os BBLs apresentaram valores de pH alcalinos em todas as temperaturas de pirólise (9,5 a 11,5). Os teores totais dos macronutrientes em todos os produtos do bagaço da laranja foram na seguinte ordem: K>Ca>P>Mg, sendo que o K em BBL, produzido a 700 ºC, foi o mais elevado. Para os micronutrientes a ordem foi: Fe>B>Mn>Zn>Cu>Mo, com maior valor de Fe em CBL. O fracionamento do bagaço da laranja em todas as formas de uso apresentou elevados teores de P, variando as formas em função dos tratamentos. O fósforo total (PT), fósforo associado aos minerais (PAM) e fósforo residual (PR) foram encontrados em maiores concentrações no tratamento sob aplicação de BBL 700 °C, fósforo solúvel (PS) em solo+CBL, e fósforo lábil (PLAB), fósforo adsorvido (PAD) em solo+SFS. A aplicação de CBL no solo influenciou positivamente o desenvolvimento das plantas de alface, sendo o tratamento com maiores médias para todas as variáveis fitométricas, com exceção da variável MVR, cuja maior média foi obtida no tratamento solo+BMBL, no entanto sem diferença estatística para o tratamento solo+CBL. A pirólise do bagaço da laranja a 500 °C e o CBL produziram características químicas promissoras, mostrando potencial para serem utilizados na melhoria da qualidade do solo. O CBL pode ser usado como fonte de P mais prontamente disponível, diferente de BBL 300 e 500 °C que apresentaram frações distintas e possivelmente uma liberação de P para o solo mais lenta. Solo+CBL proporcionou maior concentração de P solúvel no solo. As variáveis fitométricas das plantas de alface foram influenciadas positivamente pelos tratamentos solo+BBL 300 °C, solo+CBL, solo+BMBL, quando comparados aos demais tratamentos. Todos os tratamentos elevaram os teores de P nos tecidos foliares das plantas de alface, quando comparados ao solo+SFS.Brazil is one of the main orange juice exporting countries in the world. The processing of the orange to obtain the juice, generates a large amount of solid residues, these residues can cause environmental, social and economic problems, their easy fermentation and decomposition, exhale odor and contribute to the proliferation of pathogens and leaching of nutrients such as P. The use of agribusiness residues as a nutrient-rich bioproduct can make a significant contribution to the environment and the sustainability of production. The objective was to produce and characterize the biochar, biomass and orange pomace compound and to evaluate their potential in supplying phosphorus. The characterization of biochar, biomass, composed of orange bagasse, and fractionation of the phosphorus of these products was carried out, as well as the potential as a source of P of the bioproducts, using lettuce as an indicator plant. Biochar (BBL) was produced at 300; 500 and 700 ºC, biomass (BMBL) and orange bagasse compound (CBL), analyzed and tested by adding them to the soil. The BBL yield was higher at the pyrolysis temperature of 300 ºC and lower at 700 ºC. BBLs showed alkaline pH values at all pyrolysis temperatures (9.5 to 11.5). The total content of macronutrients in all products of the orange pomace was in the following order: K> Ca> P> Mg, with K in BBL, produced at 700 ºC, being the highest. For micronutrients the order was: Fe> B> Mn> Zn> Cu> Mo, with the highest Fe value in CBL. The fractionation of the orange pomace in all forms of use showed high levels of P, varying the forms depending on the treatments. Total phosphorus (PT), phosphorus associated with minerals (PAM) and residual phosphorus (PR) were found in higher concentrations in the treatment under application of BBL 700 °C, soluble phosphorus (PS) in soil+CBL, and labile phosphorus (PLAB), adsorbed phosphorus (PAD) in soil + SFS. The application of CBL in the soil positively influenced the development of lettuce plants, with the treatment with the highest averages for all phytometric variables, except for the MVR variable, whose highest average was obtained in the soil + BMBL treatment, however without statistical difference for soil treatment+CBL. Pyrolysis of orange bagasse at 500 °C and CBL produced promising chemical characteristics, showing the potential to be used to improve soil quality. CBL can be used as a more readily available source of P, different from BBL 300 and 500 °C, which presented different fractions and possibly a slower release of P into the soil. Soil+CBL provided a higher concentration of soluble P in the soil. The phytometric variables of the lettuce plants were positively influenced by the treatments soil+BBL 300 °C, soil + CBL, soil+BMBL, when compared to the other treatments. All treatments increased the levels of P in the leaf tissues of lettuce plants, when compared to soil+SFS

SOIL ACIDITY AND SOY PHYTOMETRY UNDER APPLICATION OF LIMESTONE AND AGRICULTURAL GYPSUM

The soybean is one of the main agricultural crops in Brazil, because the use of its grains is an important source of protein and vegetable oil. One of the main limiting factors for obtaining high yields in soybean in tropical soils is related to the need to correct soil acidity. The objective of the study was to evaluate the development of (Glycine max (L.) Merrill) and the variation of pH values ​​of the soil under the application of limestone and agricultural gypsum. The experimental design was completely randomized, distributed in a 4x4 factorial scheme. The treatments consisted of doses of 0, 1,5, 3,0 and 4,5 t ha-1 of only limestone, only gypsum and the combination of limestone and gypsum, repeated four times, totaling 64 experimental units. The soil pH was evaluated at 30 (pH1), 45 (pH2), 60 (pH3), 75 (pH4) days before sowing. The plant variables were: number of pods (NP), shoot green mass (SGM), shoot dry mass (SDM), root green mass (RGM), root dry mass (RDM), root length (RL) and shoot / root ratio (S/RR). The variables pH4, SGM, RL and S/RR were significantly influenced by the treatments, alone or in interaction. For pH1, pH2, pH3, NP and SDM, there were isolated effects of treatments for gypsum and limestone. At the RGM the deformation was significant for limestone and gypsum interaction with limestone. For RDM, the effect of the treatment was verified only with the use of limestone. As a conclusion, the application of limestone and gypsum reduces the soil acidity, obtaining higher pH values ​​from the doses of 3000 kg ha-1, with the combination of limestone and gypsum. The use of gypsum consortium with limestone promotes significant results in the development of soybean plants.The soybean is one of the main agricultural crops in Brazil, because the use of its grains is an important source of protein and vegetable oil. One of the main limiting factors for obtaining high yields in soybean in tropical soils is related to the need to correct soil acidity. The objective of this study was to evaluate the growth of (Glycine max (L.) Merrill) and the variation of soil pH values under the application of limestone and agricultural gypsum. The experimental design was completely randomized, distributed in a 4x4 factorial scheme. The treatments consisted of doses of 0, 1.5, 3.0 and 4.5 t ha-1 of only limestone, only gypsum and the combination of limestone and gypsum, repeated four times, totaling 64 experimental units. The soil pH was evaluated at 30, 45, 60, 75 days before sowing. The growth variables were: number of pods, shoot dry mass, root dry mass, root length and shoot/root ratio. The variables pH 75 days, root length and shoot/root ratio were significantly influenced by the treatments, alone or in interaction. For pH 30, pH 45 and pH 60 days, number of pods and shoot dry mass, there were isolated effects of treatments for gypsum and limestone. In root dry mass, the effect of the treatment was verified only with the use of limestone. As a conclusion, the application of limestone and gypsum reduces the soil acidity, obtaining higher pH values from the doses of 3000 kg ha-1, with the combination of limestone and gypsum. The use of gypsum consortium with limestone promotes significant results in the growth of soybean plants