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Evaluation of nutrient conditions in open hydroponic system based on tomato production
116-119Views:69Monoculture caused a gradual decline of soil conditions, while nematodes and salt accumulation stimulated the growers to choose alternative practices, such as soilless cultures, which proved their value in Western Europe. Exact statistics are lacking, but estimates deal with approximately 300-400 hectares of vegetable on rock wool, whereas other substrates of soilless culture may multiply this number. Real perspectives are attributed to the forced production of pepper, tomato and cucumber.
Vegetable production in greenhouses may impair the ecological balance of the environment substantially as far as being uncontrolled. Soilless cultures especially should be handled thoughtfully. A fraction of the nutrients administered, more than 25-30%, is doomed to be lost in an open system, and the resulting ecological risk is accompanied with increasing costs of the production.
In Hungary, the quantity of nutrient elements in drainage water is unknown, et all. Connecting the production results with chemical analysis, we gain more information about it.
You can see a mathematical method for evaluation of nutrient and water conditions in tomato hydroponics production. -
Evaluation of chickpea (Cicer arietinum L.) in response to salinity stress
105-110Views:202Soil salinity is a severe and expanding soil degradation problem that affects 80 million ha of arable lands globally. Chickpea (Cicer arietinum L.) is very sensitive to saline conditions; the most susceptible genotypes may die in just 25 mM NaCl in hydroponics. Approximately 8–10% yield loss in chickpea production is estimated due to salinity stress. However, it is still not established why chickpea is so susceptible to salt affection. Salinity (NaCl) impedes germination of seeds, though chickpea varieties considerably differ from one another in this respect. Some chickpea genotypes are more tolerant in the stage of germination, tolerating even 320 mM NaCl. The reasons of this variation are unrevealed; there is a shortage of knowledge about the germination abilities of chickpea genotypes in saline conditions. Nevertheless, the effect of salt stress on vegetative growth can be analysed in hydroponics, in pot or field conditions, regardless the experimental environment, the ranking of genotypes regarding salt resistance is coherent. Chickpea genotypes can be different in their ability to retain water, maybe under salt affection; the more salt tolerant lines can maintain higher water content in the shoots, while the more sensitive ones cannot. The identification of salt tolerant chickpea landraces based on developing genetic variability is a suitable strategy to combat against salinity problems arising in arid and semi-arid areas.
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Basil (Ocimum basilicum L.) harvest and plant replacement methods in aquaponia
91-98Views:29The aim of the study is to investigate the potential of basil leaf mass production under aquaponic conditions with different harvest and plant replacement methods. Aquaponics is a combination of soil-less crop production hydroponics and aquaculture and it is can use and clean the wastewater of intensive aquaculture systems. Three groups were established in the 6 units during the six-week harvest and seedling rotation cycles. Group 1 individuals remain in the units throughout the breeding season. Group 2 individuals were replaced every 12 weeks, while Group 3 individuals were replaced every six weeks, at the same time as harvest. Data from the experiment were analysed to determine how the harvest and replacement protocol of basil plants influences the amount of leaves harvested, the percentage of leaves harvested relative to the plant stem, and the changes in plant height, SPAD and NDVI during harvest and replacement. A continuously maintained and harvested healthy basil stock under aquaponic conditions can provide a consistent leaf mass all year round without the extra cost of replacing and producing seedlings.
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The effect of dissolved oxygen on common carp (Cyprinus carpio) and basil (Ocimum basilicum) in the aquaponics system
89-96Views:275Aquaponics is an integrated system that combines fish farming (aquaculture) and hydroponic plant production. The objective of this study was to examine how the level of dissolved oxygen with or without an air pump affects water quality, fish output and plant growth parameters for common carp (Cyprinus carpio) and basil (Ocimum basilicum).
Ebb – and flood aquaponics systems (with automatic syphon) was used. Two treatments were set in this experiment, one of which was the aquaponics system without air pump (unit I), where water of the plant bed was pumped two directions, one falling back to the fish tank oxygenating the water the other was pumped to the hydroponics unit. The other system (unit II) was designed with an air pump.
In the course of the study, water quality parameters, such as oxygen saturation, dissolved oxygen (DO), electrical conductivity (EC) and nitrite were significantly different (p<0.05). Total basil biomass was higher in unit II. (5367.41 g). The final biomass of common carp were
2829.45 g ± 79.24 and 2980.6 g ± 64.13 g in unit I and unit II respectively. Weight gain (WG) and specific growth rate (SGR) showed no significant differences (p>0.05) between the treatments. -
Practical experiences of a designing and operating a pilot aquaponic system
27-32Views:237Aquaponics is the combination of fish farming (aquaculture) and the soilless cultivation of plants (hydroponics). The aquaponics system is an artificial, recirculating ecosystem, in which bacterial processes convert the waste materials in the water used for fish rearing into plant nutrients, and therefore with the generated heat it is suitable for culturing economically valuable plants, and thus it mitigates the nutrient laden and quantity of the intensive fish producing systems’ effluent water.
The primary goal of our 12 separate unit’s aquaponics system was to gain experience. We would like to find the right plant species, which are fit for that medium, and their crop can be sold. Besides the plants, our attention focused on the fish. Two fish species were included in the experiments, the common carp and barramundi. It was difficult to create them a perfect living space, besides a constantly changing conditions temperature. Apart the above mentioned we had a problem with the number of individuals per tank, the deformity of the fish body and the too high volume of pH (we registered continuous values above 8.4). We get by carps 4.7 grams of weight gain during 15 weeks, because of the bad conditions.
The main problems at the plants are caused by aphesis and protection against sunburn. Even so we have got the multiples of field yields for each plant species. At salad has grown twice of field yields, tomatoes one and half, kohlrabi than 3.5 times more. The causes of multiple yields are the continuous balanced water and the nutrient uptake of plants. Each plant species fit for cultivating in aquaponics and their crops are delicious, chemical -free, safe and marketable. The plants should be more concentrated. After the experiment, it has been determinated that the carp is suitable for aquaponics, but greater weight gain could be achieved with optimal selection of size of rearing units.