Qualidade da água utilizada para irrigação de hortaliças na região de Botucatu-SP

This work had as objective verifies the water quality used for irrigation by the vegetables producers of Botucatu-SP area. They were interviewed 27 producers that sell vegetables in the street markets of Botucatu. Among these producers, ten were selected, being one of each place. Three samples of water of each source were collected. The main standard to evaluate the obtained results were the CONAMA Resolution (National Environment Council) N° 357, March 17, 2005, that it establishes the standard for water classification. The Electric Conductivity was evaluated of agreement value suggested by CETESB and the color was verified according to OMS (Health World Organization), for potable water due to CONAMA Resolution not to stipulate a value for classification. For the public health, just the coliformes and nitrate are the preoccupying variables for they be related with the incidence of diseases, so, the analyzed waters, 40% of them (A, F, H and J producers) offer some risk for the health of Botucatu population, second established standard for CONAMA. We can to conclude that in a general way, those waters, are in conditions no alarming, because they don't present values very different from those established by the legislation.

Efeito de níveis de irrigação em substratos para a produção de mudas de ipê-roxo

The aim of this work was to evaluate the ipê-roxo (Tabebuia impetiginosa (Mart.) Standl). seedlings behavior in different substrates and irrigation levels and also study the use of urban waste compost in the substrates. The experiment was conducted in the agricultural engineering department at the Faculdade de Ciências Agrárias e Veterinárias - UNESP, Campus de Jaboticabal, SP. The experimental design used was the completely randomized with 30 treats and 2 replicates, in a 15× 2 factorial arrangement [15 substrates and 2 irrigation levels (100% and 150% of evapotranspiration)]. The substrates were composed by different material combinations: urban waste, Plantmax, tanned cattle manure, vermiculite and soil. For the study of the seedlings development, the following characteristics were evaluated: the seedlings height (H) and stem diameter (D). Evaluations (H and D) were made on 90, 105, 120, 135 and 150 days after sowing. The statistical analysis showed significant differences between the irrigation levels. According to the results, we can conclude that urban waste compost did not increase Blake development. For tested irrigation levels, the statistical analysis showed significant differences with better results for the 150% ET irrigation level compared to 100% ET.

Enxertia e água de irrigação carbonatada no transporte de 15N e na produção do tomateiro

The effects of CO2 application through irrigation water, and of grafting in transport of 15N and in the tomato production, were studied. These treatments were arranged in a 2 x 2 factorial scheme (with and without CO2 in irrigation water and grafted and non-grafted tomato), in a completely randomized design, with four replications. The injection of CO2 into the water began at 34 days after transplant of seedlings (DAT) and continued for all irrigations. The application of the sulfate of ammonium with abundance in atoms of 15N of 3.13% in plants destined to analysis was done at 45 DAT when the plants were in the middle of fructification. After 14 days of fertilizer (15N) application the plants were harvested, washed, dried and sent for analysis of 15N in plant tissue. The results demonstrated that CO2 and the grafting did not alter the transport of 15N in the plant. The production of commercial fruits was larger when CO2 was applied in water.

Análise distribuição da carga hidráulica e vazão na unidade operacional de um sistema de irrigação localizada

The different combination possibilities of emission uniformity and field slope within the operational unities of localized irrigation systems favor the occurence of some configurations in the irrigation system, and consequently different hydraulic head distributions, discharge and system management. After the system has been implanted, it is necessary to verify pressure and discharge distribution in the operational unit. This work objective was to verify pressure and discharge uniformity on derivation line and lateral lines with micro sprinkle in data gotten from operational research. The results allow to check that despite analyzed declivity; the higher the emission uniformity calculated for the line of derivation in the project is, the higher its pressure uniformity is. Previously the results of discharge in the emitters of the operational unit showed a constant variation entering the point of higher discharge and lower discharge, even though differently from the three tested irrigation blades.

Irrigação por gotejamento subsuperficial na produção e qualidade de cana-de-açúcar

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação entre trȩs métodos para estimar lâminas de irrigação

An experiment with four treatments was carried out on the experimental area of ADEI to compare three methods of water use requirement: ETc (T1) - irrigation based on crop evapotranspiration (ETc); Tensiometers (T2 and T3) - irrigations were made through reading of tensiometers installed at 40 cm deep and, Control (T4) - only one irrigation to promote the seedlings emergence. Both Class A pan and soil water depletion methods presented good results when the crop was developed without restraint of water. The Katerji method can be utilized in conditions of water restriction. Irrigation frequency was more important than amount of applied water for higher yield.

Compactação do solo e intervalo hídrico ótimo no crescimento da parte aérea e produtividade da cultura do milho

The aim of this work was to evaluate the effect of soil compaction caused by tractor wheel traffic on the limiting water range (LLWR), shoot growth and levels of compaction and four replications in a completely randomized experimental design. Soil samples with preserved structure were collected in the layers: 0.02-0.05; 0.08-0.11; 0.15-0.18 and 0.22-0.25m to determine macroporosity, microporosity, total porosity, bulk density, resistance to penetration and LLWR. The evaluated corn parameters were: plant and first spike height, steam diameter, number of spikes per plant, plant dry matter, dry matter of 1000 seeds and seed productivity. The soil compaction restricted all corn parameters except the number of spikes per plant and dry matter of 1000 seeds. The LLWR was reduced by the soil resistance to penetration, even in the tilled soil with bulk density of 1.12 Mg m-3. Only the treatment with 11 Mg tractor, repeated four times on the area, demonstrated bulk density above critical bulk density in the LLWR that was 1.37 Mg m-3, where the seed productivity was significantly smaller.

Efeito de métodos de determinação de parâmetros para o controle da irrigação na eficência do uso da água do feijoeiro, sob três diferentes lâminas de água no solo

The objective of this research was to study three methods of parameter determination for irrigation control under different tensions in common bean (Phaseolus vulgaris L.). The treatments were a combination of three methods of parameter determination for irrigation control (tensiometer, water retention curve, USWB Class A pan) with three soil water tensions (1:-30 kPa; 2:-60, kPa both for the whole plant cycle; 3:-60 kPa for the vegetative phase and -30 kPa for the reproductive phase). The experimental design was randomized blocks, factorial 32 with three replicates. Although no significant effect on water use efficiency was found, a tendency for increasing water use efficiency in treatments with tensions of -60 kPa at the vegetative phase and -30 kPa at the reproductive phase was observed in all methods of parameter determination for irrigation control. Water was saved as less irrigation was applied during the vegetative phase and more irrigation at the reproductive phase. No precipitation was observed from June to September 1995, leading to a high yield and therefore to a higher water use efficiency.

Tamanho da amostra foliar para avaliação do estado nutricional de goiabeiras com e sem irrigação

The ideal size precision of the foliar sample determines manual work optimization, and also diminishes inherent errors in diagnosis reports of nutritional state. This work aimed to determine the size of the foliar samples and the sample error variation in guava plantations submitted to two hydric cultivations for the nutritional state diagnosis of this fruit. The work included two studies, both under an entirely randomized experimental design. Study 1 was carried out in an orchard under unirrigated cultivation with four treatments and six repetitions that consisted of leaf collection in 5, 10, 20 and 40 plants. Study 2 was carried out in an orchard under irrigated cultivation with five treatments and 10 repetitions that consisted of leaf collection in 10, 20, 30, 40 and 50 guava plants. It was concluded that in unirrigated orchards it is necessary to sample leaves in 40 plants in order to keep the macronutrients sample error between 5 to 10%. For the micronutrients, on the other hand, at least 40 plants were necessary and, if Fe and Zn were considered, the sample must be even larger. In irrigated orchards, leaves deriving from 10 plants were enough to keep the sample error between 5 to 10%. However, considering the micronutrients, it was necessary to sample 20 guava plants.

La eficacia de la política fiscal y los déficit privados: un enfoque macroeconómico

Incluye Bibliografía

Viabilidade econômica e seleção de sistemas de irrigação utilizando simulação e dominância estocástica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Irrigação de pastagens via pivô central, na bovinocultura de corte

The aims of this work were to show the pasture irrigation system by center pivot with Brazilian cattle and to discuss the economic feasibility of this technique in different regions of the country. Important parameters to dry matter production of tropical forage plants, as temperature, solar radiation, fertilization, and water requirement were shown Also, the system advantages and disadvantages and a discussion about economic feasibility of this technique were presented. It was concluded that pasture irrigation is a feasible and economical technique to some specific Brazilian regions, depending on appropriated parameters. This work also concludes that just water supply is not enough to assure forage production avoiding reduction in dry production in the winter.

Qualidade da água para irrigação na microbacia do Coqueiro, Estado de São Paulo

The aim of this study was to evaluate the physico chemical characteristics of water quality for irrigation purposes in the micro basin of Coqueiro, a tributary on the right bank of the São José dos Dourados river, located between the municipalities of Jales, São Francisco, Palmeira d'Oeste and Dirce Reis, in the state of São Paulo, Brazil. Water samples were collected at five geo-referenced points along the stocam and analysed monthly for one year. The parameters analysed were: suspended and dissolved solids, turbidity, electrical conductivity, pH, calcium, magnesium, hardness and total iron. The result showed that the physico chemical parameters had the classification of medium potential for damage to the irrigation system, except total iron, which was classified as having medium to high potential for damage by clogging for localized irrigation systems.

Análise multivariada na determinação do risco de erosão em solos sob irrigação

The objective of this work was to verify the application of cluster analysis to evaluate soil erosion risk for different soil classes, soil slopes and soil managements. The study was conducted in a 33 ha section of a large field located in Carmo do Rio Claro County, MG, Brazil. The field had been managed in a corn/bean rotation under conventional tillage and under coffee plantation for seven years, both under sprinkle irrigation. Soil samples were obtained at every 10 m at 0.20 m depth along a transect of 1050 m. Soil erosion risk (A), natural potential erosion (PN), and erosion expectation (EE) were determined and submitted to a cluster and principal component analysis. The application of clustering analysis showed high correlation between the clusters and soil types. With clustering analysis plus principal components analysis, it was possible to identify groups of high and low soil erosion expectation, showing that the areas with higher soil erosion expectation are correlated to the soil class, soil slope and soil management. Among the studied variables, the natural potential erosion (PN) showed to be the most important factor to identify different soil erosion groups. The cluster analysis showed that 98% of the variables were classified within each group, and that they should be managed differently due to the soil erosive potential of each group,.

Características fotossintéticas de genótipos de capim-elefante anão (Pennisetum purpureum Schum.), em estresse hídrico

The experiment was carried out aiming to evaluate the gas exchange of dwarf elephant grass genotypes under different hydric conditions, in a randomized design with three replications. Genotypes of dwarf elephant grass (Mott, CNPGL 94-34-3 and CNPGL 92-198-7) were analyzed under two hydric conditions: irrigated (I) and non-irrigated (NI). Differences between treatments I and NI were observed for all genotypes for photosynthesis, stomatal conductance, transpiration and water vapor pressure deficit. Genotype CNPGL 94-34-3 presented highest tolerance to hydric stress, followed by Mott and CNPGL 92-198-7 genotypes. All genotypes presented high photosynthetic rate, under ideal conditions of soil humidity, thus characterizing the analyzed dwarf elephant grass genotypes as plants with high photosynthetic efficiency.