Comparative Evalution of Simplified Hydroponic Techniques for Vegetable Cultivation

Abstract

Four different simplified Hydroponic systems were evaluated for their performance regarding crop growth and micro climatic conditions. The systems used were Floating/Water culture system, Aeroponic systems like Recirculating system, Simple misting system and Simplified system without emitters. The systems were designed, fabricated and installed in the roofed area of the terrace of the auditorium building and evaluated for the growth parameters of Amaranthus crop CO1 variety during the months from November 2016 to January 2017.Evaluation of the systems were done using three cases of nutrient formulations, Macro nutrients alone as a complex (19:19:19),Urea alone and all macro and micro nutrients in Tank A -Tank B concept. Floating system used water culture principles with the crops planted in grow cups on a thermocol sheet and the roots floating in the nutrient solution in the trough. The second system was a recirculating system with the nutrient solution applied by using foggers around plant roots and the residual nutrient flowing to a separate tank from where it was recirculated. The simple misting system applies the nutrient solution by using foggers attached to the pipe and timer controlled mechanism was used to manage irrigation. The simplified system without emitters used a perforated pipe attached to a pump in a deep trough to spray the nutrient to the roots of plants. The system performance was analyzed on the basis of plant morphological parameters, cost and micro climatic conditions.. Micro climatic parameters like temperature and relative humidity were monitored inside the troughs. It was found that Simplified system without emitters almost obeyed the optimum temperature and humidity ranges. In Simple misting system and Recirculating system the average temperature was almost 30 ̊C. In Recirculating and simple misting system the humidity was less than the optimum condition, about 68%. It was found that the supply of complete macro and micro nutrients in separate tanks was ideal for proper plant growth. When comparing the Aeroponic and Hydroponic systems it was found that Floating hydroponic system was giving good plant growth parameters. Among the Aeroponicsystems, it was found that Simple misting system with timer controls gave good plant performance. More modifications of the operating conditions by painting the inside of troughs with black and the use of mist or very fine spray of nutrients instead of high application rate foggers etc are to be tried in order to standardize the results.