21 research outputs found

    Effect of Pesticides on Enzymatic Activity in Soil

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    The focus of this article is to provide informations about soil enzymatic activity as a biological indicator for impacts of pesticides on soils. In this experiment, an ecological soil was treated with two types of fungicide (Ridomil Gold and Bravo 500) and two of insecticides (Mospilan 20SG and Vertimec 1.8% EC). The pesticides were assessed for their effect on different enzymatic activities. They were administrated over a 28 days period and the samples of soil were taken once every 7 days and analyzed in the laboratory. For each sample was determined the enzymatic activity, pH, humidity. The enzymatic activity was assessed using colorimetrical methods. Enzymes chosen for this study were cellulase, amylase, xylanase, urease, alkaline and acid phosphatase. Results shown that the enzymatic activity can increase or decrease when the soil was treated with the fungicides and insecticides chosen for this experiment

    Analysis of some physiological indicators in tomato plants to characterize the effects of additional lighting with blue, red and white LEDs

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    The use of light-emitting diodes (LEDs) in vegetable species is one of the technological procedures applied to improve the spectral composition of light in protected areas, as well as to stimulate plant growth, obtaining high values of production and increasing resistance to conditions of culture. The biological material represented by tomato seedlings, from varieties with nutritional value and with high ecological plasticity, was studied in terms of characterizing the effects of applying the treatment using light fields emitted by blue, red and white LEDs, by analysis physiological parameters, such as: photosynthesis intensity (μmols CO2m-2s -1), transpiration intensity (mmoles H2O m-2s -1), stomatal conductance (mols H2O m-2s -1) and intercellular carbon dioxide (mmol CO2 mol-1 air). In this study, the estimation of the amount of total chlorophyll (mg m-2), was also investigated. The determinations of the physiological parameters were performed in 3 series, and the recorded results were statistically analysed, by expressing the significance of the differences between the control and the studied tomato varieties being studied. Thus, after the treatment period, applied in 23 days (Series II), with monochrome LEDs, at the level of the stomatal conductance parameter, statistically assured values were registered for the plants in the ‘L-75’ line exposed to White LED and for those in the ‘L-76’ line exposed to the Blue LED. The analysis of the results from the investigation of the physiological parameters at the level of the leaves from the experimental samples indicated that after 35 days (Series III), from the application of the treatments of 30 minutes/day, with White LED light, they ensured the plants tomatoes from the ‘L-76’ line, distinctly significantly positive values, compared to those of the control plants, at the intensity of photosynthesis and the internal concentration of CO2

    THE INFLUENCE OF WHEAT AND MAIZE CULTURES ON ROTATION AND MONOCULTURE ON THE ENZYMATIC COMPONENTS OF THE SOIL

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    In order to better characterize the soil's vitality and to assess the fertility level, pedo-enzymatic tests are used along with biotic and / or chemical analyzes. Pedo-enzymatic activities are evaluated in the laboratory to determine the potentials of a soil to release the ammonium and phosphorus required for soil and plant micropopulation nutrition. Pedo-enzymatic processes (pedo-phosphatase, pedo-amidase) are ongoing, to the extent that environmental conditions are favorable. The soil samples taken in the study were harvested from the Am (0-20 cm) horizon of the N0P70 fertilized variant, from the following crops: wheat after soybean crops of a three-year rotation, maize coming from a 4-year field temporarely outside the crop rotation, and from monocultures of wheat and maize. From the data analyzed as a result of this study it results that the crop rotation influences the pedo-enzymatic components of the soil. Total pedo-phosphatase activity in wheat and maize cultivation (rotating) was superior, the results being in the value group compared to the total pedo-phosphatase activity of the soil under the wheat and maize monocultures where the result of the analyzes indicated a much lower, being in b. The total soil pedo-amidase activity of wheat cultivated with maize as a precursor plant was superior, the result being in the a

    Pilot Aquaponic Growing System of Carp (Cyprinus Carpio) and Basil (Ocimum Basilicum)

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    AbstractThe aquaponic recirculating systems are integrated systems that combine fish and plant culture. These systems consist of two components: aquaculture and hydroponics components. In these systems the nutrients necessary for plant growth are resulted from the metabolism of food by the fish. This was obtained by recirculation of water, with a pump, from the fish tank to the hydroponic component and back to the fish tank. The experiment was conducted in the laboratory of Fisheries and Aquaculture of the Faculty of Animal Husbandry of University of Agronomic Sciences and Veterinary Medicine of Bucharest for 6 months. The system developed here, is a 1 m2 area of plant growth and 0.45 m3 of water in aquaculture component. In the hydroponic component river gravel was selected to support the plants and offer support for the growth and developing of nitrifying bacteria. The species cultivated were cultured carp (Cyprinus carpio) and basil (Ocimum basilicum). On average, there was obtained a quantity of about 1kg basil leaves in a period of 60 days of growth. It has been found that the species of plants grown in this system, namely basil (Ocimum basilicum) grown with carp (Cyprinus carpio), has a faster and better development compared to conventional growth. Use of basil as a purifying plant, resulted in the removal of nitrates, being not necessary to add additional water, as in classical recirculating systems, where is necessary to replace daily approx. 10% of the volume of the culture water being necessary to add into the system only water lost through evaporation. According to the results the basil is suitable for aquaponic system with carp culture. The basil was grown much better than the conventional cultivation
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