جستجوی مقالات مرتبط با کلیدواژه "hydroponics" در نشریات گروه "منابع طبیعی"

The water shortage crisis necessitates the implementation of new technologies to increase water productivity. The aeroponics and hydroponics methods can be part of these technologies. In this study a high pressure aeroponics system including two separate units was designed and constructed for conducting research experiments. In this technology, the roots of the plant were suspended in a horizontal arrangement in the air and subjected to periodic spraying of the nutrient solution. The nutrient solution based on Hoagland's formula was transferred by a diaphragm pump and after passing through the filter, it was sprayed on the roots of the plants through the nozzle at regular intervals. Other equipment such as pressure switch, pressure gauge, drain valve, programmable timer, and diaphragm accumulator were used in the hydraulic circuit of the system. The sprayed solution was collected at the end of the chamber and returned to the tank due to the gravity force. The design was such that there is always some solution in the bottom of the tank and the roots can use this solution as well, so this system can be considered as a hybrid type. The results showed that this hybrid method significantly increased leaves and root growth compared to the traditional method. The systems built in this research are part of the path to better use of agricultural water and still need to be optimized. Due to the development of vertical farming and urban agriculture in the world, aeroponics systems can play a significant role in this regard.

Most growers do not pay attention to the issue of proper nutrition, including the proper ratio of elements in the nutrient solution and changing the concentration of each element and their ratio at different stages growth. Lack of available information in this regard, in the present study, it has been decided to evaluate the effect of different ratios of nitrogen and potassium on the quantitative and qualitative characteristics of tomato fruit under hydroponic conditions. The balance of nutrients in the culture medium is one of the factors affecting the yield and quality of crops and horticulture. The present study was conducted to investigate the effects of different ratios of nitrogen and potassium on the quantitative and qualitative characteristics of Hirad tomato fruit in hydroponic conditions.

Treatments include concentrations of nitrogen and potassium in the vegetative and reproductive period including 1) nitrogen and potassium at concentrations of 130 and 250 ppm in the vegetative stage and 160 and 350 ppm in the reproductive stage; 2) nitrogen and potassium at concentrations of 140 and 260 ppm in the vegetative stage and 170 and 360 ppm in the reproductive stage, respectively; 3) nitrogen and potassium at concentrations of 150 and 270 ppm in the vegetative stage and 180 and 370 ppm in the reproductive stage, respectively; and 4) nitrogen and potassium were at concentrations of 160 and 280 ppm in the vegetative stage and 190 and 380 ppm in the reproductive stage, respectively.

The results showed that the nutrition of tomato plant with different ratios of nitrogen and potassium affects different characteristics of the plant such as quantitative and qualitative indicators. The highest stem diameter value was obtained in the vegetative and reproductive stages in treatment 3. Treatment 2 showed the highest yield of single plant, total acid and fruit lycopene, and in treatment 4, the highest amount of fruit chlorophyll and soluble solids was observed.

Also, the highest ascorbic acid content was obtained in treatment 1.In general, in order to achieve maximum yield and improve the quality of tomato fruit, it is recommended to use more potassium and less nitrogen.