Design and Development of Indigenous Hydroponic System for Small Farming in Pakistan

Abstract

Three greenhouses (sheds) were built at the University Research Farm. Construction materials of the sheds included galvanized mild steel frames of square pipes were from indigenous origin in order to reduce the initial cost of the structure. Roofs of the greenhouses were kept as truss structures. Each of the three sheds was differently clad for investigating the efficacy of materials in managing light and heat for the inside plants. The cladding materials included polythene, fiber glass, polythene and insect-screen. Two of the sheds were equipped with cooling pads and exhaust fans on the opposite walls for temperature control, whereas temperature regulation in the third shed is through natural ventilation. Five growth media (coco imported, indigenous coco, indigenous coco plus 25 percent zero grade stone crush by weight, rice husk, and rice husk plus 25 percent zero grade stone crush by weight), and three media carriers (plastic slabs 102.0 cm × 20.3 cm × 7.6 cm, PVC pipes 30.5 cm long, 11 cm diameter and used plastic bottles of 2.5 liters having 33 cm length and 10 cm diameter on top side) were selected. During experimentation, climatic variables such as light intensity, temperature and humidity inside the shed were monitored in the greenhouses. Nutrient rich solution was applied using drip irrigation. Crop growth parameters like plant height, stem diameter, number of flowers trusses number of clusters and inter nodal distance were evaluated at appropriate time intervals for retrieving useful information and preparation of recommendations for the end users interested in hydroponics agriculture. Roof cladding of greenhouses with insect-screen over polythene registered ideal performance. Polythene cladding of walls demanded careful handling during construction as well as operation. Fiberglass indicated little or no signs of aging after two years of cropping. The average weights of ripened fruits are 7.94, 6.57 and 4.37 kilograms per plant for polythene, fiberglass and insect-screen plus polythene clad greenhouses respectively. Coco-imported scored highest position among other growing substrates with rice husk at the second position in terms of crop responses. Coco-indigenous had comparably low performance that may be associated with its unskilled preparation technique alone. For second cropping season coco-imported performed the best among the growing materials showing a yield of 7.5 kilograms per plant that amounts to 90 tons of tomatoes per acre. If the tomato is sold at rate of Rs.50/kg, the turnout from the acre would be 4.5 million PKR.