Ecology, Environment and Conservation Paper

WATER PRODUCTIVITY OF IRRIGATED AGRICULTURE IN DIFFERENT IRRIGATION ENVIRONMENTS OF TAMIL NADU: POTENTIAL AREAS FOR IMPROVEMENT

T.M. Kamesh, D. Suresh Kumar, A. Vidhyavathi, K. Nagarajan and M.R. Duraisamy

Abstract

Water Productivity (WP) refers to the efficiency with which water resources are utilized to achieve desired outcomes, such as agricultural production, industrial processes, or domestic use. Irrigated agriculture in World Cropland is accounted as only 16 per cent but those lands yield some 36 per cent of the total world yield water supply for use in irrigated lands may be limited as a result of increased water use. The objective of the study is to explore the scope for water productivity enhancement in irrigated agriculture of different irrigation environments in Tamil Nadu. Purposive and multi-stage sampling technique is followed for the selection of study area and sample respondents. The Physical Water Productivity (PWP) and Economic Water Productivity (EWP) of a purely irrigated crop are estimated under different irrigation methods/ technologies. In order to know the potential of water control in improving crop water productivity, the incremental changes in crop yield and crop water productivity to irrigation were analyzed. The results indicates that PWP are 0.4 kg of paddy, 0.45 of groundnut and 0.5 kg of black gram in tank irrigation environment, 1.7 kg of maize, 5.26 kg of tapioca, 0.26 kg of sorghum in well irrigation environment, 0.2 kg of paddy, 0.35 kg of turmeric, 5.16 kg of sugarcane and 1.04 kg of banana in canal irrigation environment. The EWP are Rs. 1.61 for paddy, Rs. 2.98 for groundnut and Rs. 18.42 in black gram in tank irrigation environments, Rs. 5.78 in maize, Rs. 4.69 in tapioca and Rs. 9.03 in sorghum in well irrigation environments and Rs. 0.98 in paddy, Rs. 9.69 in turmeric, Rs. 1.66 in sugarcane and Rs. 3.43 in a banana crop of canal irrigation environments. The regression values for the yield response to irrigation dosage are quite tiny. It is possible to claim that irrigation alone cannot fully account for fluctuations in yield. There are three basic types of irrigation dose responses for yield and water production. In the first instance, the yield and applied water have a positive but shaky connection, while the reaction of the WP to applied water is inverse and exponential. The second scenario is one in which there is a substantial and positive correlation between applied water and yield, with the majority of farmers applying water under a regime of water scarcity and relatively few under a regime of water excess. In the third scenario, the yield and applied water have a “polynomial” relationship, shows that the yield rises with irrigation dose up to a certain point and then starts to fall. In this scenario, WP quickly decreases the point that corresponds to the maximum yield as the water dose is increased.