944 resultados para Irrigation farming.
Resumo:
The aim of this study was to compare wild boar (chromosomal number 2n = 36) to phenotypically similar animals of 2n = 37 and 2n = 38 chromosomes (crossbreeds) with respect to live weight, carcass yield, meat yield, fat and weight of inner organs. All animals were born and raised on the same farm and slaughtered at 39 weeks. The final live weight of wild boar 2n = 36 was significantly lower (47.2 kg) as compared to crossbreeds (80.0 kg). Animals 2n = 36 had more carcass yields (65.5%) than 2n = 37 karyotype (64.9%) and 2n = 38 (64.4%). Wild boar had the highest yields for the cuts with bones and boneless cuts compared to crossbreeds. Therefore, variations in karyotype are accompanied by differences in some carcass quantitative traits, i.e., 2n = 36 grow and fatten slower than crossbreeds 2n = 37 and 2n = 38. (c) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Through the analysis of Mexican livestock statistics and Sonora and Chihuahua regional census, this work discusses the condition of livestock farming in Northern Mexico during the first decades of the twentieth century, specially after the Revolution. There is no doubt that during this period, the absolute number of livestock heads diminished throughout Mexico, but "estate depredations" did vary geographically. In Nortehrn Mexico, livestock farming suffered more in Chihuahua than in Sonora, and herd recovery was also faster in Sonora. This analysis also allows us to underscore the role of postrevolutionary elites in rebuilding regional economies during the 1920's.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
The aim of this work was to observe the interaction between soil moisture and irrigation time intervals on the germination of sugarcane cv. RB785148 sets in semi-controlled conditions. One-bud sets of the variety RB785148 were germinated in ceramic pots filled with soil under a transparent PVC cover using soil humidity levels of 22, 25 and 30%, that were restored at intervals of 7, 14 and 21 days. The experiment was carried out at three different periods of the year: May-June/94; Oct.-Nov./94; and Mar.-Apr./95. The results indicate that the germination decreased mainly in function of the decrease in soil humidity, whereas irrigation interval have no statistical effect on germination. An interaction between humidity level and irrigation interval was observed. A variation of the timecourse of the germination could be observed when the results of the experiments installed at different dates were compared.
Resumo:
It is presented two study cases about the approach in root analysis at field and laboratory conditions based on digital image analysis. Grapevine (Vitis vinifera L.) and date palm (Phoenix dactylifera L.) root systems were analyzed by both the monolith and trench wall method aided by digital image analysis. Correlation between root parameters and their fractional distribution over the soil profile were obtained, as well as the root diameter estimation. Results have shown the feasibility of digital image analysis for evaluation of root distribution.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
The purpose of this study was to carry out a scanning electron microscopic (SEM) analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots); Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots); Group 3: 2.0% chlorhexidine (10 roots); Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots); Group 5: saline solution (5 roots); Group 6: saline solution and 17% EDTA for 2 minutes (5 roots). After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05) for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.
Resumo:
Objective. To assess the potential for contamination of wastewaters from pig farming. Methods. Wastewaters from pig farming were stored in a tank. After 0, 30, 60, 90, and 120 days of hydraulic retention, they were added to lysimeters filled with argillaceous, sandy, or medium soil. Finally, these lysimeters were submitted to simulations of either a rainy season or a dry season. The number of colony-forming units (CFUs) of total coliforms, fecal coliforms, and fecal streptococci was measured in the effluents of the storage tank (for the various periods of hydraulic retention), in the percolate from the lysimeters, and in the three types of soil. The microbiological analyses were carried out using the membrane filter technique. The pH analyses were done potentiometrically. Results. For the three microorganisms, the largest decrease in bacterial counts in the storage tanks occurred with 90 or 120 days of retention. There was a marked decrease in the bacterial count in the percolates of the three soils. For the three soil types the greatest reduction in bacterial counts was found in medium soil, due to its acidity (pH < 7.0). Hydraulic retention was not sufficient to ensure the sanitary adequacy of the wastewaters and their use for irrigation, given that fecal coliform values were above 1 000 CFU per 100 mL. Therefore, adding the residues to the soil was considered a second stage of treatment. Conclusions. The retention of wastewaters followed by adding them to soil was effective in minimizing the contaminating effect of pig farming residues. The storage time for wastewaters from pig farming could be decreased from 120 to 90 days.
Resumo:
The biotechnology, biochemical characterization, and protective effects of the himematsutake and shiitake mushrooms were studied for the Thematic Project, from 1998 to 2003. A new species, Agaricus Brasiliens is Wasser et al. (= A. blazei Murrill ss. Heinem.), was proposed for the cultivated lineages in Brazil. Interactions among lineages, substrates, casing layers, and fructification inductions (temperature alternations) significantly increased the productivity of A. brasiliensis in Brazil (from 40 g to 200 g of fresh mushroom kg -1 moist compost). However, pests and diseases (mainly Sciaridae flies and false truffle), drastically reduced the productivity of A. brasiliensis (below 50 g kg -1). Biochemically for each mushroom species, the polar extracts, no polars, and medium polarity presented the same organic substances; however, their concentrations differed as a result of the lineages, maturation of the fruit bodies, and cultivation conditions. In this aspect, concentration of linoleic acid in A. brasiliensis (added to animal food) was related directly to the chemical protection against carcinogenic drugs in mice. Aqueous extracts of Lentinus edodes (= Lentinula edodes (Berk.) Pegler) and A. brasiliensis may be preventive chemical protectors against mutagenic and carcinogenic drugs, depending on the lineage and extraction method (tea or juice). However, immunomodulator effects and tumor reduction were only observed with concentrated fractions (hexanic, methanolic, and ATF extracts). Aqueous extracts of A. brasiliensis and L. edodes have antibiotic-like substances and substances able to act as elicitors of resistance responses in some plants (local and systemic) and show a potential to be used in the alternative control of plant pathogens. © 2005 by Begell House, Inc.
Resumo:
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.
Resumo:
A new device for irrigation, which presents hydrodynamic activation based on the pressure-suction technology, has recently been introduced to the market: the Rinsendo system. This study compared the efficacy of the Rinsendo system and conventional (manualdynamic) irrigation in the removal of debris from the root canal walls, using scanning electron microscopy (SEM). Twenty mandibular premolars with completely formed roots were selected and randomly divided into group 1 (irrigation with the Rinsendo system) and group 2 (conventional irrigation). The canals were irrigated with 1 ml of saline at each change of instrument. instrumentation started with a #15 K file and continued up to a #40 K file, which was standardized as the working length instrument. Then, the teeth were sectioned in buccolingual direction and the halves were sputter-coated with gold and examined by SEM. The apical, middle and cervical root canal thirds were evaluated, and the results were analyzed statistically by the Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds, and Miller test for individual comparisons. A significance level of 5% was set for all analyses. The results did not show significant differences (p>0.05) between methods at each third and among thirds for each technique analyzed individually. in conclusion, there was no difference in the cleaning ability of the Rinsendo system and conventional irrigation.
Resumo:
The aim of this study was to evaluate dry matter yield and nutritional value of palisade grass (Brachiaria brizantha cv. Marandu) using nitrogen doses and sprinkler irrigation in two periods of the year, aiming at reducing seasonality of forage production. It was used a randomized block design in a split-plot scheme, with five doses of nitrogen (0, 50, 100, 150, and 200 kg/ha/cut), and the sub-plots were defined by the seasons of the year (wet and dry season), with and without irrigation. During the wet season, in the plots with and without irrigation, doses of 175 and 161 kg/ha/cut promoted the highest dry matter yields. During the dry season, 171 kg ha -1N with irrigation resulted in the highest dry matter yield. During the same season, there was no response to N fertilization in the lack of irrigation. Average contents of CP were 10% with and without irrigation. Contents of neutral detergent fiber decreased with nitrogen doses, while acid detergent fiber was not affected by fertilization. Plots under irrigation reached the maximal acid detergent fiber content at N dose of 60 kg ha -1. Irrigation promotes increase of 15% increase in dry matter yield and it increases contents of neutral detergent fiber. © 2010 Sociedade Brasileira de Zootecnia.
Resumo:
The present study aimed to assess the behavior of seedlings of Schizolobium parahyba (Vell.) Blake growing on different substrates and irrigation levels, and to study the use of urban waste compost in substrates. The experiment was carried out in the College of Agricultural Sciences, Universidade Estadual Paulista (UNESP), Department of Agricultural Engineering, Jaboticabal Campus, state of São Paulo, Brazil. The experimental design used was completely randomized, consisting of 30 treatments in a factorial design with 15 substrates and two irrigation levels in four replicates. The substrates were composed of different materials: urban waste, Plantmax®, dry cattle manure, vermiculite and soil. For the study of seedling growth, the following characteristics were evaluated: height (H), root-collar diameter (D), number of leaves, shoot dry weight, root dry weight, total dry weight, H/D ratio, Dickson's quality index, and the ratio between height and shoot dry weight (H/SDW). Assessments of the first three characteristics were carried out 20, 35, 50 and 65 days after sowing. Results showed that urban waste compost increased the growth of Schizolobium parahyba. There were significant differences for the irrigation levels tested; with better results for 150% ET compared to 100% ET irrigation level.
Resumo:
A theoretical model was developed in order to determine the optimal moment for substituting the sprayer and pressure regulator kit on a center pivot irrigation machine. The model is based on the hypothesis that pressure regulator and sprayer deterioration decrease irrigation uniformity. To compensate the deficit that happens at under irrigated areas, an increase on irrigation depth is required. The model considers: additional water consumption and energy costs, maintenance and labor costs, as well as yield losses associated with under or over irrigated areas. The sum of all these components is compared to buying and installing a new spray kit cost, allowing the farmer to decide the best moment to renovate the sprayer and pressure regulator kits on a center pivot irrigation machine based on economic criteria.
Resumo:
A theoretical model developed by the authors for determining the optimal moment to substitute sprayer and pressure regulator kit on a center pivot irrigating potatoes and beans has been applied. The methodology compares the sum of the costs due to additional consumption of water and energy, maintenance and labor, as well as yield losses associated to areas with deficit or over irrigation to the costs due to buy and install a new sprinkling set on the pivot. The results showed that for a reduction of 3.07% of the Hermann and Hein’s Uniformity Coefficient (UCh), the substitution of the sprinkling module on the pivot is justified when potatoes and beans are cultivated.