ABSTRACT Currently in Brazil, large grain cultivation projects on Plinthosols are a reality, however, there is little or no knowledge of the real mechanism of formation of the plinthite feature, in addition to what is reported in the literature as being a product of oxidation-reduction processes of iron element. This study evaluates iron redoximorphic features and investigates their chemical and mineralogical composition in two profiles of Plinthosols from the Araguaia River plain (P1 and P2). The study strengthens the understanding of the pedogenetic processes involved in the formation of mottles and plinthite. In this sense, it assesses whether the formation mechanisms corroborate the literature. Soil features were sampled in the upper right and left position at the initial plinthic horizon, upper right and left position at the main plinthic horizon, and lower right position at the base horizon of the plinthite zone in the profile. Separated samples comprising the soil matrix, mottles, and plinthite under natural moisture conditions were ground into powder form for chemical determinations by X-ray fluorescence (XRF), sulfuric acid attack (H2SO4), sodium dithionite-citrate-bicarbonate (DCB), and ammonium acid oxalate; and mineralogical determinations by X-ray diffraction. Iron contents in all determined forms were always higher in the plinthite feature, intermediate in the mottle feature, and lower in the soil matrix feature. Most of the Fe in all redoximorphic features is included in the structure of primary minerals and their derivatives (vermiculite, illite, and VHEs). Only part of the iron present (about 35.40 % in P1 and 41.98 % in P2) is detected in the form of oxides such as goethite and hematite, which could be formed in redox processes. The mottle and plinthite features under study are not the product of the classic process of segregation, mobilization, and accumulation of iron as a consequence of redox processes. These features were formed or emerged as a result of a relatively slow and constant weathering process of their source material, which is gradually decomposed in an aqueous medium, releasing most of its components. These components include iron and more mobile elements such as bases and silicon, which leave the system through drainage water, and of which a small part may eventually recombine to form new less complex minerals such as kaolinite and oxides. Brazil reality however feature oxidationreduction oxidation reduction element P (P P2. P2 . sense profile Xray X ray XRF, XRF , (XRF) H2SO4, H2SO4 HSO H SO (H2SO4) dithionitecitratebicarbonate dithionite citrate bicarbonate DCB, DCB (DCB) oxalate diffraction vermiculite, vermiculite (vermiculite illite VHEs. VHEs VHEs) about 3540 35 40 35.4 4198 41 98 41.9 hematite segregation mobilization material medium silicon water (XRF H2SO (H2SO4 (DCB 354 3 4 35. 419 9 41. (H2SO

Resumo Após o processamento dos citros, são gerados resíduos que podem ser utilizados na extração do óleo essencial. Assim, o objetivo deste trabalho foi avaliar a composição, o rendimento e a qualidade do óleo comprovado de 30 variedades de laranja, como alternativa para o melhor aproveitamento dos resíduos. As cascas foram trituradas e submetidas à hidrodestilação em máquina tipo Clevenger. As amostras foram submetidas a um Delineamento Inteiramente Casualizado (DIC), e os resultados foram analisados em Análise de Variância, Análise de Componentes Principais e Análise de Agrupamento Hierárquico. As variedades Valência IAC (5,57%), Pera DP 06 (4,75%), Hamlin 20 (4,58%) e Pera DP 25 (4,28%) apresentaram os maiores ganhos em óleo essencial. Valência IAC tem potencial para extrair até 7,24 kg de óleoessencial por tonelada de laranja. O limoneno representa entre 93,18 e 99,61% do óleo, sendo ocomposto majoritário entre as variedades. Algumas variedades não descrevem compostos secundários, ou mais de um composto secundário. Esses componentes são altamente antioxidantes e degrande importância na produção de cosméticos, produtos de higiene pessoal,homeopatia, uso em doenças gastrointestinais, entre outros. É possível concluir que as variedadespossuem diferentes compostos e óleos, mesmo quando submetidas ao mesmo processo de secagem e de extração do óleo, sendo as características intrínsecas de cada variedade. citros essencial Assim composição 3 laranja Clevenger DIC, DIC , (DIC) Variância Hierárquico 5,57%, 557 5,57% 5 57 (5,57%) 0 4,75%, 475 4,75% 4 75 (4,75%) 2 4,58% 458 58 (4,58% 4,28% 428 28 (4,28% 724 7 24 7,2 9318 93 18 93,1 9961 99 61 99,61 secundários secundário cosméticos pessoalhomeopatia pessoal homeopatia pessoal,homeopatia gastrointestinais outros óleos variedade (DIC 55 5,57 (5,57% 47 4,75 (4,75% 4,58 45 (4,58 4,28 42 (4,28 72 7, 931 9 1 93, 996 6 99,6 5,5 (5,57 4,7 (4,75 4,5 (4,5 4,2 (4,2 99, 5, (5,5 4, (4,7 (4, (5, (4 (5 (

Abstract Residues are generated after the processing of citrus fruits and can be used for essential oil extraction. Thus, the objective of this work was to evaluate the composition, yield, and quality of the proven oil of 30 orange varieties, as an alternative for the better use of its residues. The peels were crushed and subjected to hydrodistillation in a Clevenger-type. The samples were submitted to an Entirely Randomized Design (DIC) and the results were analyzed in Analysis of Variance, Principal Component Analysis, and Hierarchical Cluster Analysis. The greatest gains in essential oil were yielded by the varieties Valencia IAC (5.57%), Pera DP 06 (4.75%), Hamlin 20 (4.58%), and Pera DP 25 (4.28%). Valencia IAC has the potential to extract up to 7.24 kg of essential oil per ton of orange. Limonene represents 93.18 to 99.61% of the oil components, being the major compound among all varieties. Some varieties did not describe secondary compounds or more than one. These components are highly antioxidant and of great importance in the production of cosmetics, personal care products, homeopathy, help gastrointestinal diseases, among other uses. It is possible to conclude that the varieties have different compounds and oils, even when submitted to the same drying and oil extraction process, being the intrinsic characteristics of each variety. Thus composition yield 3 residues Clevengertype. Clevengertype Clevenger type. type Clevenger-type DIC (DIC Variance 5.57%, 557 5.57% , 5 57 (5.57%) 0 4.75%, 475 4.75% 4 75 (4.75%) 2 4.58%, 458 4.58% 58 (4.58%) 4.28%. 428 4.28% . 28 (4.28%) 724 7 24 7.2 9318 93 18 93.1 9961 99 61 99.61 one cosmetics products homeopathy diseases uses oils process variety 55 5.57 (5.57% 47 4.75 (4.75% 45 4.58 (4.58% 42 4.28 (4.28% 72 7. 931 9 1 93. 996 6 99.6 5.5 (5.57 4.7 (4.75 4.5 (4.58 4.2 (4.28 99. 5. (5.5 4. (4.7 (4.5 (4.2 (5. (4. (5 (4 (

Abstract The objective of this study is to evaluate the effects of sources and doses of boron on the physiological quality and production yield of Phaseolus vulgaris grown using a central pivot irrigated system on a tropical climate region. The experiment was a 4 x 5 factorial design representing four sources of boron (boric acid, borax, borogran and FTE BR 12) and five boron doses (0, 1, 2, 3 and 4 kg ha-1), with four replications. The following parameters were measured: relative chlorophyll index, transpiration, CO2 internal concentration, stomatal conductance, net photosynthesis, B content, grain yield and economic analysis. The relative chlorophyll index (RCI) of plants showed no significant effects at both 28 and 46 days after emergence (DAE). The extraction order of boron was boric acid > borax > FTE BR12 > Borogran. The application of boron did not affect the physiological quality (stomatal conductance, transpiration and internal concentration of CO2). However, the net photosynthetic rate was lower when boric acid was applied in relation to other sources. The maximum production (4,446 kg ha-1) was obtained using 1.35 kg ha-1 of B with the use of boric acid. However, according to an evaluation of economic viability, it is observed that there are economic differences among sources of boron and evaluated doses. The application of 4 kg ha-1 of borax provides the highest economic return.

Ratoon sugarcane response to potassium is dependent on the environmental conditions of the region. Cropping systems that do not burn crop biomass after harvest leave crop residues on the soil, affecting the soil-plant nutrient dynamics system and fertilizer requirements. The objective of this study was to evaluate the effect of potassium fertilization of first and second ratoon sugarcane crops on potassium contents in the soil, in the plant, and yield and quality of stalksin an Oxisol under a conservation cropping system. The following potassium rates were tested: 0, 27, 54, 108, and 162 kg K ha-1, arranged in a randomized block design with five replicates. The application of potassium increased soil nutrient concentrations at six months, reaching 2.87 and 2.61 mmol c dm-3 with the highest rate in the first and second ratoons, respectively. The increase in available exchangeable-K content in the soil favored a greater plant uptake of this nutrient, reaching 12.1 and 10.0 g kg-1 in the first and second ratoons, respectively. The increase in potassium absorption by plants was reflected in the production of stems; the highest yields (87.0 and 132.9 t ha-1) were obtained with the application of 162 kg K ha-1 in the first and second ratoons, respectively.

The presence of mulch on the soil surface after the mechanical harvesting of sugarcane (Saccharum officinarum L.) enhances the cycling of nutrients, especially K, which can decrease K fertilizer recommendations for the crop. The aim of this study was to evaluate the effect of K addition to an Oxisol, with an initial concentration 0.07 cmol c K kg-1, in first and second ratoon (no-till) sugarcane cultures by a conservationist system, i.e. rational use of fertilizers, use of alternative inputs and especially the maintenance of residues in soil that was previously burned to facilitate cutting. The following K doses were tested: 0, 32.5, 65, 130, and 195 kg K2O ha-1, arranged in a randomized block design with five replicates. Potassium content in the soil and in the plant, as well as the yield and the quality of stalks were evaluated. Soil K application increased K concentration in soil and plant, and was reflected in the production of stalks, with higher production (87.5 and 107.5 t ha-1) with the use of 120 and 123 kg K2O ha-1 in first and second ratoon sugarcane, respectively. At the first 2 yr it was not possible to reduce the K fertilization in ratoon. Therefore, with the introduction of the conservationist system there was an increase (20 t ha-1) at the second ratoon regarding the first one with the same applied rate.

Na colheita mecanizada sem o uso de fogo ocorre deposição de palhada na superfície do solo, a qual pode ser reciclada e reduzir a adubação potássica para a cana-de-açúcar, em relação à cana queimada, o que pode refletir em menor custo de produção. Objetivou-se avaliar o efeito da aplicação de potássio no desenvolvimento inicial da soqueira de primeiro corte da cana-de-açúcar (variedade SP 89-1115), em sistema de colheita sem despalha a fogo. O experimento foi instalado em uma área de primeira soqueira de cana-de-açúcar, cultivada em Latossolo Vermelho, textura argilosa. Os tratamentos foram constituídos por cinco doses de K2O (0 kg ha-1; 32,5 kg ha-1; 65,0 kg ha-1; 130,0 kg ha-1; e 195,0 kg ha-1), na forma de KCl, aplicado em 2009, dispostos em blocos casualizados e com cinco repetições. As variáveis de crescimento avaliadas foram: número de perfilhos, altura de planta e diâmetro de colmo, aos 120 dias após o brotamento. A aplicação de potássio proporcionou incremento com ajuste linear do teor de potássio no solo, nas camadas 0-0,20 m e 0,20-0,40 m de profundidade, atingindo 0,18 cmol c dm-3 e 0,12 cmol c dm-3, respectivamente, para a maior dose de K. A aplicação de K não afetou o número de perfilhos e diâmetro de colmo, mas influenciou a altura, atingindo maior valor na dose de 195,0 kg ha-1 de K2O.

In the mechanized harvesting without the use of fire, there is deposition of straw on the soil surface, which may be recycled and reduce the potassium fertilization for sugarcane, if compared to the burned sugarcane, what may reflect in a lower production cost. This study aimed to evaluate the potassium application effect in the early development of first cutting sugarcane ratoon (SP 89-1115), in an unburned harvesting system. The experiment was installed in a first sugarcane ratoon area, in a clay Oxisol. The treatments consisted of five K2O doses (0 kg ha-1, 32.5 kg ha-1, 65.0 kg ha-1, 130.0 kg ha-1, and 195.0 kg ha-1), as KCl, applied in 2009, in a randomized blocks design with five replications. The growth variables measured were number of tillers, plant height, and stem diameter, 120 days after budding. The potassium application provided a linear increase in the soil potassium content, at the 0-0.20 m and 0.20-0.40 m depth layers, reaching, respectively, 0.18 cmol c dm-3 and 0.12 cmol c dm-3, for the highest K dose. The K fertilization did not affect the number of tillers and stem diameter, but it affected plant height, which reached its highest value at 195.0 kg ha-1 of K2O.