Influência da aplicação de vinhaça na capacidade de Infiltração de um solo de textura franco arenosa

The objective of this study was to analyze effects in different depth in soil water infiltration and to verify the Horton and Kostiakov-Lewis models adequacy in infiltration rate estimate. The treatments were five doses of vinasse (0, 200, 250, 300 and 350 m3?ha1?. The vinasse application reduced the soil erosion risk increasing the possibility of runoff. The Horton model had the best adjustment on the observed data, and the Kostiakov-Lewis model overestimated the infiltration rate values.

Variabilidade dos atributos de um latossolo vermelho sob plantio direto no cerrado brasileiro e produtividade da soja

The spatial variability of several soil attributes (bulk density, penetration resistance, water content, organic matter content and pH) as well as soybean yield have been assessed during the 2007/08 growing season, in Selviria (MS) in a Hapludox (Typic Acrustox), under no tillage. The objectives were to assess the spatial variability of soil and plant parameters at the small plot scale and to select the best soil attribute explaining most the variability of agricultural productivity. Soil and plant were sampled on a grid with 121 points within a plot of 25,600 m 2 in area and slope of 0.025 mm -1 slope. Medium and low coefficients of variation were obtained for most of the studied soil attributes as expected, due to the homogenizing effect of the no-till system on the soil physical environment. From the standpoint of linear regression and spatial pattern of variability, productivity of soybeans could be explained according to the hydrogen potential (pH). Results are discussed taken into account that the soybean crop in no-tillage is widely used in crop-livestock integration on the national scene.

Variabilidade espacial na produção da alface em ambiente protegido

Este artigo mostra a dinâmica da água após ser aplicada sobre a superfície de um solo cultivado com alface, num sistema fechado de um ambiente protegido. A aplicação de água se deu por meio de um sistema de irrigação por gotejamento, com o CUD ( Coeficiente de Uniformidade de Distribuição ) igual a 97,06 %, o que garantiu uma ótima uniformidade de distribuição, desconsiderando como possíveis causas das variações de umidade do solo, a aplicação de lâminas variadas. Fazendo uso de técnicas de geoestatística, interpolando sessenta pontos amostrais de evaporação, umidade do solo e produtividade da alface, com as mesmas sessenta coordenadas para os três atributos, verificou-se que a umidade do solo, mesmo momentos após a irrigação, não permanece uniforme ao longo do sistema de irrigação, constatando-se que a evaporação local exerce influência de forma predominante sobre a dinâmica da água na superfície do solo. Concluiu-se que as regiões no interior da estufa de maiores evaporações, foram as de maiores variações de umidade do solo e na produção de massa verde da alface.

Influência de Manejos de irrigação sobre aspectos de Ecofisiologia e de produção da videira cv. Syrah / Paulsen 1103

O manejo de irrigação pode influenciar o comportamento ecofisiológico e a produção da videira. O objetivo desse trabalho, conduzido em 2010 em Petrolina – PE, no Submédio do Vale do São Francisco, foi avaliar a influência de diferentes estratégias de manejo de irrigação no potencial de água na folha e em aspectos qualitativos e quantitativos das uvas do primeiro ciclo de produção da videira cv. Syrah/Paulsen 1103. O sistema de irrigação utilizado foi gotejamento e a lâmina de água foi estimada com base na evapotranspiração da cultura. O delineamento experimental utilizado foi o de blocos casualizados, em 4 repetições e com 3 tratamentos: irrigação plena, realizada durante todo o ciclo de produção; a irrigação com déficit, onde a aplicação de água foi interrompida na fase fenológica de cacho fechado; e a irrigação com déficit controlado, onde a irrigação, também interrompida na fase de cacho fechado, foi eventualmente realizada após a interrupção, de acordo com o monitoramento da água no solo. A imposição de déficit hídrico às plantas favoreceu uma maior concentração de açúcares e a redução da acidez nos frutos, contribuindo para a melhoria da qualidade das uvas para vinificação.

Fracionamento da fertirrigação e seu efeito na produção da alface sob ambiente protegido

Buscando quantificar o efeito do parcelamento da fertirrigação no desenvolvimento da alface, esta pesquisa procurou verificar o número de parcelas de fertirrigação que apresentasse o melhor desempenho no crescimento da cultura. O experimento se deu em blocos casualizados, com três repetições, quatro tratamentos de fertirrigação e três lâminas de irrigação (L1, L2 e L3). Em um dos tratamentos de fertirrigação (F1), toda a adubação necessária se deu no início do plantio; no tratamento F2, a metade da adubação se deu no início do plantio e a outra metade no meio do ciclo da cultura, uma vez planejada a colheita em 40 dias após o plantio; o tratamento F3 foi fracionado: 1/3 da adubação no início do plantio, 1/3 depois de 13 dias e o ultimo terço após 26 dias do plantio; o tratamento F4 seguiu o mesmo raciocínio, fracionando a aplicação em 4 partes, de 10 em 10 dias. Logo, os quatro tratamentos de fertirrigação receberam a mesma dosagem de fertilizantes. Os resultados permitiram concluir que a aplicação F1 resultou no pior desempenho, com massa fresca de 135,06 gramas por planta, enquanto o melhor resultado se deu no tratamento F2, com massa fresca de 161,40 g. Em todas as lâminas, o parcelamento F3 resultou em sistema radicular mais desenvolvido. O tratamento L1 apresentou em média maior desenvolvimento das raízes, seguido do L2 e L3. O tratamento L1 apresentou menor condutividade elétrica no extrato da solução dos vasos, sendo o único tratamento que diferiu estatisticamente dos demais.

Resposta produtiva do feijoeiro comum a diferentes manejos de irrigação

The objective of this work was to analyze the most appropriate management to achieve higher productivity for carioca beans (phaseolus vulgaris) and pearll cultivar. The research was developed in the Demonstrative and Experimental Area of Irrigation (ADEI) of FCAV/UNESP, Campus of Jaboticabal, SP. Four treatments were used: T1- irrigation with base in ETo estimated by the method of Class A pan; T2- irrigations based on the readings of tensiometers installed at 0,20 m and 0,40 m of depth; T3- irrigations carried out with base in ETo estimated by the method of Penman-Monteith and T4- witness. The results were submitted to analysis of variance. To compare the averages the test Turkey was used at 5% of probability. The treatment T3 had smaller applied water depth than the treatments T1 and T2, and also smaller productivity. The conclusion is that the treatments irrigated with larger frequency showed higher production of grains.

Porosidade e infiltração de água do solo sob diferentes sistemas de manejo

Management systems affect soil structure, causing changes in porosity that can influence water infiltration into the soil. This study aimed to evaluate the effect of different management systems on the porosity and water infiltration in Distroferric Red Nitosol with clay texture. The management systems were: conventional with disc plow + two soft harrowing, conventional with heavy disc harrow + two soft harrowing, no tillage and fallow. The following attributes: porosity, pore shape and water infiltration velocity into the soil were determined. Management systems such as no-tillage, conventional with disc plow and heavy disc harrow, and fallow modify the porosity and the shape of pores of a Distroferric Red Nitosol, influencing water infiltration, which was favored in no-tillage for the greater presence of elongated pores.

Manejo da Irrigação Para Otimização da Produtividade E Qualidade de Frutos de Tomateiro em Sistema de Plantio Direto

There is much information on the adequate soil water matrix potential for returning irrigation in conventional soil tillage systems; however there is not enough information on the best soil water matrix potential for no-tillage production systems. This work aimed to study the effect of five irrigation levels on yield, soluble solids, and fruit acidity of the Hypeel tomato, cultivated for industrial processing and cropped on no-tillage system in Yellow Latosol. The experiment was carried out on a randomized block design with five treatments and four replications. The treatments consisted in different soil water matrix potentials for returning irrigation (m at 13cm of soil depth): -15, -30, -45, -60 and -75 kPa. The results obtained showed that the soil water matrix potential of -28.5 kPa resulted in maximum yields for tomato crop; whereas the value of -50.8 kPa resulted in the maximum fruit soluble solids concentration.

Produção e Qualidade Física dos Frutos do Abacaxi sob Diferentes Lâminas e Frequências de Irrigação

The objective of this study was to evaluate the performance of pineapple cultivar Smooth Cayenne as the physical production and the quality of the fruit when subjected to different frequencies of water dpeth and soil water in Triângulo Mineiro - Uberaba-MG. The experimental area soil is Oxisol, clay loam sandy and soft undulating local relief. A randomized block design in a factorial 4 x 2 with four levels of soil water depth (50%, 75%, 100% and 125%) of crop evapotranspiration (ETc) and two irrigation frequencies (1 day and 3 days = F1 = F2) and four replications was utilized. The crop productivity, number of seedlings, mean weight, diameter, and hardness of the fruit, plus water use efficiency were evaluated. Productivity was not significantly affected by the water depth and by the frequency of water applied; however the fruit shell resistance, the efficiency of water use, and ratoon seedlings were significantly influenced by irrigation, the water depth of 50% of the crop evapotranspiration (ETC) provided greater efficiency of water use for the production of pineapple fruit.

Estimativa Da Água No Solo Em Floresta de Eucalyptus Grandis

The study aimed to assess the moisture and density of the soil, the amount of water stored in the profile, and the average soil's porosity with Eucalyptus grandis reforestation, compared to bare soil. The study areas are located in the Paulista region, in São Paulo, Brazil. The samples were collected in layers of 0, 20, 40, 60, 100 and 300 cm, in the months of April, June, August and October 2008. The results show that the density is lower and the porosity is higher in Eucalyptus forest soil compared to bare soil, due to the higher content of organic matter in forest leaf litter. Furthermore, the forest soil has a lower amount of water stored in profile than the bare soil without vegetation.

Déficit hídrico na eficiência de herbicidas e nas características bioquímicas de Euphorbia heterophylla

The objective of this work was to evaluate conditions the effectiveness of acetolactate synthase (ALS) and protoporphyrinogen oxidase (PROTOX) inhibitors in the Bidens pilosa control under two water deficit conditions, as well as to determine the action under the content of soluble carbohydrates and protein and free amino acids of weed. The experimental design was randomized completely design, with four replications, with the treatments setup in a factorial scheme 4x2, with four herbicides (fomesafen lactofen, chlorimuron-ethyl and imazethapyr), and two soil water conditions (-0.5 MPa and -0.01MPa). At 7, 14, 21 and 28 days after application (DAA), was assessed visually control efficiency of herbicides. For the determination of organic solutes plants were collected at 24, 48, 72 and 96 hours after application (HAA), except for the amino acids were analyzed 48, 72 e 96 HAA. Herbicides fomesafen and lactofen were efficient to control E. heterophylla, while the ALS inhibitors (chlorimuron-ethyl e imazethapyr) provided an unsatisfactory control. Water deficit altered the efficiency of herbicides, mainly chlorimuronethyl. Lactofen provided a smaller content of soluble carbohydrates, in the same way, the protein ranged in the 72 HAA, the lower value observed for imazethapyr e lactofen respectively. Herbicide lactofen increased the concentration of free amino acids, while the imposition of water deficit caused an increase in soluble carbohydrate content.

Non-labile plant C contributes to long-lasting macroaggregation of an Oxisol

Decomposition of plant material influences soil aggregation dynamics in ways that are still poorly understood, especially for Oxisols, in which oxides are believed to play a dominant role. In an incubation experiment, we investigated (i) the effect of plant material addition from selected monocot and dicot species on soil organic C (SOC), carbohydrate composition, fungal and total microbial biomass, and aggregation of an Oxisol; and (ii) the relationship among these properties and C mineralization patterns. The experiment was carried out at 25 °C for 180 d after addition of 11 plant materials (4 g C kg-1 soil) and a control (no plant material added). Mineralization of C during the incubation was described considering two pools of C (labile and non-labile) using a first-order plus linear fitting. Compared to the control, corn materials showed larger pentose input, greater mineralization rates for the non-labile C pool (k), greater soil pentose content (xylose + arabinose) and larger mean weight diameter of soil water-stable aggregates at 180 d of incubation. These effects were independent of changes in SOC content, suggesting that total C accrual and macroaggregation may be decoupled processes in this Oxisol. Our results support the hypothesis that the non-labile plant C pool contributes to the long-lasting stability of macroaggregates of this Oxisol and that this effect is mediated by plant and soil pentoses. We propose that plant pentose content and the decomposition rate of the slow pool (k) are useful parameters for the prediction of plant effects on aggregation dynamics of Oxisols and the selection of soil conservation practices. © 2012.

Reservoir design and operation: Effects on aquatic biota-a case study of planktonic copepods

Copepod assemblages from two cascade reservoirs were analyzed during two consecutive years. The upstream reservoir (Chavantes) is a storage system with a high water retention time (WRT of 400 days), and the downstream one (Salto Grande) is a run-of-river system with only 1. 5 days WRT. Copepod composition, richness, abundance, and diversity were correlated with the limnological variables and the hydrological and morphometric features. Standard methods were employed for zooplankton sampling and analysis (vertical 50-μm net hauls and counting under a stereomicroscope). Two hypotheses were postulated and confirmed through the data obtained: (1) compartmentalization is more pronounced in the storage reservoir and determines the differences in the copepod assemblage structure; and (2) the assemblages are more homogeneous in the run-of-river reservoir, where the abundance decreases because of the predominance of washout effects. For both reservoirs, the upstream zone is more distinctive. In addition, in the smaller reservoir the influence of the input from tributaries is stronger (turbid waters). Richness did not differ significantly among seasons, but abundance was higher in the run-of-river reservoir during summer. © 2012 Springer Science+Business Media Dordrecht.

Sistemas de manejo e atributos físico-hídricos de um Latossolo Vermelho cultivado com milho

The purpose of this experiment was to evaluate the hydro-physical attributes of the Red Oxisol cultivated with maize in Jaboticabal, São Paulo State, Brazil, under different systems of use and periods of adoption of managements. The experiment was arranged in a completely randomized design with split-plot arrangement, with six replications and the treatments were: six years of no-tillage system (SPD6), eight years of no-tillage system (SPD8), ten years of no-tillage system (SPD10), conventional tillage system (SPC) and an adjacent area of native forest (NF). The soil penetration resistance (PR), density, macroporosity, microporosity of the soil in layers of 0-0.05; 0.05-0.10 and 0.10-0.20 m, and the saturated hydraulic conductivity (Kθ) in 0.15 m depth were evaluated. It was found that the PR conditions were favorable for the cultivation to 0.20 m, indicating a structure preserved even after soil chiseling. Furthermore, the Kθ in the soil showed similar behavior between SPC and periods of SPD, although this was shown in a part of maize cycle, macroporosity values near 0.10 m3 m-3 and soil water tensions near 0.09 MPa.

Análise das tensões de água no solo cultivado com morangueiro sob poda

Strawberry yield and quality was evaluated after drastic pruning (second cycle), under different soil water tensions, drip irrigation. The experiment was conducted on beds at a greenhouse, located at Engineering Department, Federal University of Lavras (UFLA), from April to December of 2010. An experimental design was in randomized blocks with three replicates. The treatments were composed of six different soil water tension, 15, 25, 35, 45, 55 e 70 kPa. Results obtained allowed to verify that to higher values of: total and commercial fresh weight of fruits per plant, total and commercial number fruits per plant and total and commercial yield, it is necessary to irrigate when soil water tension gets approximately to 15 kPa, at 0.15 m deep. Commercial average fruit mass and noncommercial fresh weight of fruits per plant, were not reduced under different soil water tensions applied.