Development of nano irrigation system with clay diaphragm for reduced water loss in vegetable production in low income countries

Abstract

Water resources will be more affected as the effects of climate change continues to manifest in the environment. Since agriculture in the poor countries of the world still remain largely rainfed, the effect of climate change will leave greater impact on agriculture in those countries. Any effort made to improve water use efficiency in agriculture is worthwhile. This paper presents a report of the development of nano-irrigation system using molded clay for emitter diaphragm. The clay material was sourced locally from the deposit around the pottery community in Isan-Ekiti, Nigeria. Varying quantities of sawdust was mixed with clay before molding. As a result, seven different treatments of clay: sawdust ratios were made viz; 100:0, 90:10, 80:20, 70:30, 60:40, 50:50 and 40:60. The mold samples were sundried and later fired in the kiln at 700 o C. This process helped to strengthen the molds and eliminate the sawdust burnouts. From the water discharge test conducted by connecting the emitter to the discharge end of a water-hose the 80:20 treatment showed a discharge of 8.6 x 10-6 l/s (approximately 1 liter/day). The corresponding discharges from 70:30, 60:40, 50:50 and 40:60 were 4.3 x 10-5 l/s (2 liter/day), 1.6 x 10-5 l/s (approximately 4 liter/day), 1.4 x 10-5 l/s (approximately 5 liter/day) and 1.2 x10-5 l/s (approximately 7 liter/day). Compared to the commercial drippers manufacture by Netafim Ltd the discharge was far more efficient in curtailing irrigation water loss. The 70:30 sample was found more suitable for meeting the discharge of water quantity equivalent of the water requirement of pumpkin and okra vegetables. This was confirmed in the field experiment conducted with the crop in question. On the material utilization platform, the developed emitter is 100 times cost effective when compared to cooking pot and the economic return to the rural women far outweighs that of other pottery wares.