Resposta do tomateiro à fertirrigação potássica e cobertura plástica do solo

The aim of this work was to determine the effects of fertirrigation with potassium and black polyethylene cover on tomato. A field experiment was carried out on a cambic yellowish podzolic at the Universidade Federal de Viçosa, in Viçosa, MG, Brazil. The treatments, with five replicates, following a randomized block design, were: (A) manual application of 40% of recommended K rate at the seedling transplantation row and manual sidedress application of 60%; (B) manual application of 40% of recommended K rate at the seedling transplantation row and 60% by fertirrigation; (C) similar procedure to B but with black polyethylene cover; (D) application of 100% of K rate by fertirrigation and (E) similar procedure to D but with black polyethylene cover. Treatments B, C, D and E were drip irrigated. Tomato yields were higher with K application by fertirrigation than using the manual fertilization method, but the tomato yields were not influenced by K partial or total fertirrigation neither by black polyethylene cover. The NO3--N, organic-N, K, Ca and Mg concentrations on leave petioles were not influenced by treatments.O objetivo do presente estudo foi determinar os efeitos da fertirrigação potássica e da cobertura do solo em película de plástico preto, na cultura do tomate. O experimento foi realizado na Universidade Federal de Viçosa, em solo Podzólico Vermelho-Amarelo câmbico. Os tratamentos, em cinco repetições, no delineamento em blocos casualizados, corresponderam a: (A) aplicação manual de 40% da dose recomendada de K no sulco de transplante e 60% aplicados manualmente, em cobertura; (B) aplicação manual de 40% da dose de K no sulco de transplante, e 60% aplicados por fertirrigação; (C) procedimento idêntico ao anterior, porém com o solo coberto por plástico preto;(D) aplicação de 100% da dose de K por fertirrigação e (E) procedimento idêntico ao anterior, porém com o solo coberto por plástico preto. Os tratamentos B, C, D e E foram irrigados por gotejamento. Maiores produções de tomates foram obtidas com a aplicação do K por fertirrigação do que com a aplicação manual. Estas produções, entretanto, não foram influenciadas pela aplicação total ou parcial de K por fertirrigação, nem pela presença de cobertura plástica do solo. Os teores de N-NO3-, N-orgânico, K, Ca e Mg no pecíolo do tomateiro não foram influenciados pelos tratamentos

Partition and macronutrients accumulation in pineapple under nitrogen doses and plant density

Studies related to the absorption and exportation capacity of macronutrients by irrigated pineapple are essential for the definition of adequate doses and fertilization management. The objective of this study was to evaluate the accumulation of biomass and macronutrients in the compartments (leaves, shoot, root, seedlings/slip, crown/top, and fruit) of ‘Vitória’ pineapple irrigated in the semiarid region after the use of nitrogen doses and population densities. The treatments, arranged in randomized blocks with three replicates, arranged in a 5x4 factorial scheme, consisted of five nitrogen doses (0, 5, 10, 15 and 20 g per plant) and four population densities (51,282, 76,923, 90,909, and 126,984 plants ha-1). The accumulation of biomass and macronutrients in the pineapple compartments was evaluated at the end of the growing cycle. The increase of N doses combined with the increase of the plant population promoted a linear increase in the accumulation of biomass and macronutrients by the pineapple plants. The leaves presented greater accumulation of macronutrients, followed by the seedlings, shoot, fruit, crown, and roots. The pineapple presented the following decreasing order of macronutrient absorption: K> N> Ca> P> Mg>S. At the dose of 20 g per plant of N and population of 126,984 plants ha-1 were exported from the area by fruits, 1,311 (12%), 150 (9%), 144 (11%), 52 (11%), 46 (12%) and 36 (12%) kg ha-1 of K, N, Ca, P, Mg, and S, respectively; and by the shoots, 2,426 (22%), 480 (29%), 147 (11%), 101 (21%), 67 (18%), and 45 (15%) kg ha-1 of K, N, Ca, P, Mg, and S, respectively.Studies related to the absorption and exportation capacity of macronutrients by irrigated pineapple are essential for the definition of adequate doses and fertilization management. The objective of this study was to evaluate the accumulation of biomass and macronutrients in the compartments (leaves, shoot, root, seedlings/slip, crown/top, and fruit) of ‘Vitória’ pineapple irrigated in the semiarid region after the use of nitrogen doses and population densities. The treatments, arranged in randomized blocks with three replicates, arranged in a 5x4 factorial scheme, consisted of five nitrogen doses (0, 5, 10, 15 and 20 g per plant) and four population densities (51,282, 76,923, 90,909, and 126,984 plants ha-1). The accumulation of biomass and macronutrients in the pineapple compartments was evaluated at the end of the growing cycle. The increase of N doses combined with the increase of the plant population promoted a linear increase in the accumulation of biomass and macronutrients by the pineapple plants. The leaves presented greater accumulation of macronutrients, followed by the seedlings, shoot, fruit, crown, and roots. The pineapple presented the following decreasing order of macronutrient absorption: K> N> Ca> P> Mg>S. At the dose of 20 g per plant of N and population of 126,984 plants ha-1 were exported from the area by fruits, 1,311 (12%), 150 (9%), 144 (11%), 52 (11%), 46 (12%) and 36 (12%) kg ha-1 of K, N, Ca, P, Mg, and S, respectively; and by the shoots, 2,426 (22%), 480 (29%), 147 (11%), 101 (21%), 67 (18%), and 45 (15%) kg ha-1 of K, N, Ca, P, Mg, and S, respectively

Diversidad zoológica asociada a un silvopastoreo leucaena-guinea con diferentes edades de establecimiento

The aim of this work was to evaluate the associated zoological diversity of a silvopastural system leucaena-guinea grass, by characterizing the composition and structures of the birds, insects and the macrofauna of the soil, in four establishment times of the silvopastural systems (3, 4, 5 and 6 years of exploitation). For the species recorded in each zoological group, the following ecological indices were determined: number of individuals, richness, diversity and abundance of species, in each establishment times of the system. A significant increase, in all the zoological groups, was observed for the richness of species and for the index of biological diversity of Shannon, as the system developed. An increase in the abundance of bioregulator insects was observed, and for the birds, the sampling time showed no interaction with the different sowing years. The macrofauna of the soil increased during the management of the system, and a dominance of annelids (Polyferetrina elongata and Oligochaeta elegans) was noted during the 6th and 7th year of exploitation. The silvopastural system leucaena-guinea grass increases the biomass production and other biological components, and contributes to create a sustainable system which is compatible with the environment.The aim of this work was to evaluate the associated zoological diversity of a silvopastural system leucaena-guinea grass, by characterizing the composition and structures of the birds, insects and the macrofauna of the soil, in four establishment times of the silvopastural systems (3, 4, 5 and 6 years of exploitation). For the species recorded in each zoological group, the following ecological indices were determined: number of individuals, richness, diversity and abundance of species, in each establishment times of the system. A significant increase, in all the zoological groups, was observed for the richness of species and for the index of biological diversity of Shannon, as the system developed. An increase in the abundance of bioregulator insects was observed, and for the birds, the sampling time showed no interaction with the different sowing years. The macrofauna of the soil increased during the management of the system, and a dominance of annelids (Polyferetrina elongata and Oligochaeta elegans) was noted during the 6th and 7th year of exploitation. The silvopastural system leucaena-guinea grass increases the biomass production and other biological components, and contributes to create a sustainable system which is compatible with the environment.El objetivo de este trabajo fue evaluar la diversidad zoológica asociada a un silvopastoreo con leucaena-guinea, por medio de la caracterización de la composición y estructura de las aves, insectos y la macrofauna del suelo, en cuatro edades de establecimiento (3, 4, 5 y 6 años de explotación). Con las especies registradas en cada uno de estos grupos zoológicos, se calcularon los índices ecológicos: número de individuos, riqueza, diversidad y abundancia de especies, en diferentes edades del sistema. En todos los grupos, se apreció el aumento significativo en la riqueza de especies y en el índice de diversidad biológica de Shannon, en la medida que se desarrolló el sistema. Se observó incremento en la abundancia de insectos biorreguladores y, en relación con las aves, el horario de muestreo no mostró interacción con los distintos años de siembra. La macrofauna se incrementó, observándose dominancia de anélidos al 6o y 7o año de explotación, caracterizado por Polyferetrina elongata y Oligochaeta elegans. El desarrollo del silvopastoreo leucaena-guinea logra sistemas productivos pecuarios que aumentan la producción de biomasa y de otros componentes biológicos y contribuir para crear un sistema sostenible y compatible con el ambiente

Biochar from different residues on soil properties and common bean production

The production of biochar from organic residues promises to be an interesting strategy for the management of organic waste. To assess the effect of biochar on soil properties and the production and nutrition of common bean (Phaseolus vulgaris L.), three simultaneous experiments were conducted in a greenhouse with different biochar from organic residues (rice husk, sawdust, and sorghum silage) used as filtration material for swine biofertilizer. In each experiment the treatments consisted of five different biochar concentrations (0, 25, 50, 75 and 100 L m−3), arranged in a completely randomized design, with four repetitions. In the experiments, the use of biochar increased soil pH, cation exchange capacity, nutrient availability in the soil, and nutrient accumulation in grains. The biochar concentrations corresponding to the maximum production of grain dry matter of bean plants were 100, 68, and 71 L m−3 for biochar from rice husk filter (BRHF), biochar from sawdust filter (BSF), and biochar from sorghum silage filter (BSSF), respectively

Use of Si-Phytoliths in depollution of mining areas in the Cerrado-Caatinga region, MG, Brazil

International audienceTreating of metal contaminated areas became a very important problem with increasing industrial and agricultural activities. Many of the used methods are very expensive, need intensive human interaction or have a very negative influence on the cleaned regions. The use of Si-Phytolites is a simple, low cost and a very effective way to obtain good results in low contaminated or as the final process in highly contaminated places. The method is based on the fact that a lot of plants produce Si-Phytolits and trap significant quantities of heavy metals in these amorphous to microcrystalline structures. The solubility of the Si-Phytolits under Brazilian soil conditions is lower than that of the heavy elements brought directly in the soil by the wash or fall out, or by degrading of organic parts of the plants at the upper part of surface. In this way, it is possible to retain liberation to the environment from short to longer periods and attend environmental laws and norms.Initial tests with different plants like Ricinus comunis L., Andropogon arundinaceus Willd., Zea Mays L., Brachiaria sp. L. and Saccharum officinarum L. planted on substrates with metal concentrations (Al, Fe, Mn, Ti, Zn, Cu, Pb, Cd, Ba, Hg, S) have shown that the plants absorbed elements and quantities in the different parts like leaves, roots, stems, flowers and fruits. This allows a selective use due to contamination varieties and a possible economic use of parts of the plants and an effective planning of the decontamination conditions

Biodiesel industry waste recovery in agriculture

International audienceWe examine in this study the possibility of using biodiesel industry waste mixed with urban sewage sludge as a source of nutrients for the production and seedling development in agriculture. Biodiesel industry waste is diatomaceous earth (DE) compounds and paraffin. We added DE with urban sewage sludge. The advantage of this operation is to eliminate the two wastes, residues of the biodiesel industry and sludge from wastewater treatment plants. We studied the behavior of Camaldulensis Eucalyptus and white mulberry (Morus Alba Yu vc-62).The Dickson Quality Index (DQI) of White Mulberry and Camaldulensis Eucalyptus plants tested in different substrates (urban sewage sludge and DE) are all above the minimum recommended value of 0.2. The Camaldulensis Eucalyptus and white mulberry (Morus Alba) plants have good growth in substrates containing urban sewage sludge and diatomaceous earth compared to commercial substrate used as control. Biodiesel industry waste can used up to 50% by volume of the substrate without compromising the quality of the plants with a reduction in the cost of production

Adsorção de fosfatos em três solos da região semi-árida do Rio Grande do Norte

To evaluate phosphate adsorption in Rio Grande do Norte semiarid soils, laboratory determinations were made utilizing samples collected at up to 20 cm of depth, from a Vertisol (V) and two Fluvents (Ae1 and Ae2). In these soils remaining phosphorus was determined after agitation of the samples with a solution of CaCl2 10 mmol/L containing 60 mg/L of P, for one hour. The phosphorus doses for Langmuir isotherm adjustment were defined based on the remaining P values and corresponded to 0.0; 6.0; 12.0; 18.0; 30.0; 42.0; 54.0; 66.0; 84.0; 102.0; and 120.0 mg/L. The data of adsorbed P and the concentrations of equilibrium solutions obtained after 24-hour agitation of soil samples with the solutions of CaCl2 10 mmol/L containing the above-cited P concentrations, were adjusted to Langmuir isotherm. Three different adsorption regions were identified and adjusted to linear regression models. The maximum phosphate adsorption capacity (CMAF) and the constant related to the adsorption energy of phosphates (EAF) were determined. The CMAF presented values of 0.312; 0.291 and 0.249 mg of P/cm3 of soil for soils V, Ae1 and Ae2, respectively. Phosphate adsorption was strongly influenced by the specific surface and P content of the soils. In soils V and Ae1, the remaining phosphorus decreased with and increase in the clay content, while CMAF and EAF increased with an increase in clay.Com o objetivo de avaliar a adsorção de fosfatos em solos da região semi-árida do Rio Grande do Norte, foram realizadas determinações de laboratório utilizando-se amostras, coletadas até 20 cm de profundidade, de um Vertissolo (V) e de dois solos Aluviais eutróficos (Ae1 e Ae2). Nesses solos, o P remanescente foi determinado após agitação das amostras com uma solução de CaCl2 10 mmol/L, contendo 60 mg/L de P, durante uma hora. As doses de fósforo para o ajuste da isoterma-de-Langmuir foram definidas com base nos valores de P remanescente e corresponderam a 0,0; 6,0; 12,0; 18,0; 30,0; 42,0; 54,0; 66,0; 84,0; 102,0 e 120,0 mg/L de P. Os dados de P adsorvido e as concentrações das soluções de equilíbrio, obtidos após a agitação por 24 horas das amostras de solo com as soluções de CaCl2 10 mmol/L contendo as concentrações de P supracitadas, foram ajustados à isoterma-de-Langmuir. Três diferentes regiões de adsorção foram identificadas e ajustadas a modelos de regressão linear. Foram determinadas a capacidade máxima de adsorção de fosfatos (CMAF) e a constante relacionada com a energia de adsorção de fosfatos (EAF). A CMAP apresentou valores de 0,312; 0,291 e 0,249 mg de P/cm3 de solo, para os solos V, Ae1 e Ae2, respectivamente. A adsorção de fosfatos foi fortemente influenciada pela superfície específica e pelo teor de P dos solos. Nos solos V e Ae1, o P remanescente diminuiu com o aumento do teor de argila, enquanto a CMAF e EAF aumentaram com o incremento de argila

Indicadores de qualidade do solo em cultivos irrigados de cana-de-açúcar

The objective of this work was to evaluate the effects of land use change on the dynamics of organic carbon, on total nitrogen, and on microbial soil properties over time, in irrigated sugarcane crops. The systems were evaluated in four areas with sugarcane in a chronosequence of 5, 7, 8, and 9 years of cultivation, besides a native vegetation area. The soil samples were analyzed for C and N stocks, and for the microbiological properties of the soil. The system with 8 years showed the highest C values of microbial biomass and basal respiration, and the lowest ones for microbial metabolic quotient (qCO2). The highest values of C and N stocks were observed in the native vegetation area. These results are associated with the constant deposition of litter and intense biological activity in the native vegetation. The deposition of sugarcane straw on the soil surface, over time, improved soil quality and kept the soil stocks of C and N similar to those observed in the native vegetation area.O objetivo deste trabalho foi avaliar os efeitos da mudança de uso da terra na dinâmica do carbono orgânico, no nitrogênio total e em atributos microbiológicos do solo ao longo do tempo, em cultivos irrigados de cana-de-açúcar. Os sistemas foram avaliados em quatro áreas com cana-de-açúcar, numa cronossequência com 5, 7, 8 e 9 anos de cultivo, além de uma área com vegetação nativa. As amostras foram analisadas quanto ao estoque de C e N e quanto às propriedades microbiológicas do solo. O sistema com 8 anos apresentou os maiores valores de C na biomassa microbiana e de respiração basal, bem como os menores de quociente metabólico (qCO2). Já os maiores valores de estoque de C e N foram observados na área com vegetação nativa. Estes resultados estão associados à deposição constante de serrapilheira e à intensa atividade biológica na vegetação nativa. A deposição de palhada de cana-de-açúcar sobre a superfície, ao longo tempo, melhorou a qualidade do solo e manteve os estoques de C e N semelhantes aos observados na área de vegetação nativa

Fertilidade do solo e estoques de carbono e nitrogênio sob sistemas agroflorestais no Cerrado mineiro

Agroforestry systems are used to diversify food production, provide an increase in the biodiversity of fauna and flora as well as the conservation of carbon and nutrients in the soil. Thus, the objective of this study was to evaluate the fertility and carbon (C) and nitrogen (N) stocks of the soil after ten years of agroforestry system (SAFs) implantation in the Cerrado biome of Minas Gerais state, Brazil. The study was carried out in the American Agroextractivist Settlement, located in the municipality of Grão Mogol, northern mesoregion of the state of Minas Gerais. Three SAFs and two adjacent native vegetation areas (VNs) were used as reference for the study, which were grouped according to the soil class: Red-Yellow Latosol and Haplic Cambisol. The soil sampling was carried out in March 2013, ten years after the implementation of the SAFs, where composite samples were removed from the 0-5 and 0-20 cm soil depth layers for the evaluation of nutrient contents and apparent density, and in the first layer the soil C and N stocks. SAFs that were deployed with management based on prune trees and maintenance of floristic diversity contributed with the improvement of the soil quality and the maintenance of fertility and C stocks at levels like in native vegetation. On the other hand, the SAF that was implanted with the previous suppression of the native vegetation reduced the tree diversity and, consequently, the C stocks over time. However, management with annual crops and the use of legumes contributed to the improvement of soil fertility and to the increase of N contents and stocks.Os sistemas agroflorestais são utilizados para diversificar a produção de alimentos, proporcionar aumento na biodiversidade da fauna e da flora e conservação do carbono e nutrientes no solo. Sendo assim, o objetivo deste estudo foi avaliar a fertilidade e os estoques de carbono (C) e nitrogênio (N) do solo após dez anos de implantação de sistemas agroflorestais (SAFs) no Cerrado mineiro. O estudo foi realizado no Assentamento Agroextrativista Americana, localizado no município de Grão Mogol, mesorregião norte do Estado de Minas Gerais. Foram selecionados três SAFSs e duas áreas de vegetação nativa (VN) adjacentes, utilizadas como referência para o estudo, as quais foram agrupados em função da classe de solo: Latossolo Vermelho Amarelo e Cambissolo Háplico. A amostragem do solo foi realizada em março de 2013, dez anos após a implantação dos SAFs, em que amostras compostas foram retiradas das camadas 0-5 e 0-20 cm de profundidade para avaliação dos teores de nutrientes e densidade aparente, e na primeira camada os estoques de C e N do solo. Os SAFs que foram implantados com manejo baseado em desrama e manutenção da diversidade florística contribuíram com e melhoria da qualidade do solo e manutenção da fertilidade e estoques de C em níveis semelhantes à vegetação nativa. Já o SAF que foi implantado com a prévia supressão da vegetação nativa reduziu a diversidade arbórea e, consequentemente, os estoques de C ao longo do tempo. Porém, o manejo com culturas anuais e uso de leguminosas contribuiu para a melhoria da fertilidade do solo e incremento dos teores e estoques de N