Length of Growing Period and Water Productivity of Important Crops and Cropping Systems for Coastal Areas of Haldia, Paradip and Visakhapatnam

Abstract

Scarcity of water is going to be more acute under changing climate in the coastal areas of India due to uncertainity in rainfall amount and distribution. Analysis of rainfall data from 1990-2011 at three sites viz. Visakhapatnam, Paradip and Haldia in Andhra Pradesh, Odisha and West Bengal respectively revealed that the co-efficient of variation of annual rainfall was the highest for Visakhapatnam (26.4), followed by Paradip (22.7) and Haldia (21.5). The trend analysis of long-term rainfall data revealed that the average annual rainfall declined by 6.3% at Haldia, increased by 8.5% at Paradip and declined by 14.3% at Visakhapatnam during 2001-2010 from that of 1991-2000. The crop evapotranspiration (ET_crop) computed by modified Penman method revealed that during dry season highest ET_crop was observed in case of boro rice (604.8 mm) at Haldia, for brinjal (507.2 mm) at Paradip and for sugarcane (1178.9 mm) at Visakhapatnam, whereas water productivity (WP) on the basis of economic yield was highest in case of potato at Haldia (7.2 kg m^-3) and Paradip (6.6 kg m^-3) and sugarcane at Visakhapatnam (6.7 kg m^-3). Suitable cropping systems like rice-potato, rice-sunflower for Haldia, rice-tomato, Rice-potato and rice-brinjal for Paradip and rice-chilli for Visakhapatnam may be followed to get higher WP on net return basis. Irrespective of location, the WP on net return basis was more than j- 20 m^-3 in case of rice-tomato, rice-potato, rice-brinjal, rice-onion, rice-sunflower and rice-chilli. Under changing climatic conditions, increasing degradation as well as limited availability of natural resources in coastal areas suitable cropping systems should be identified and followed for better water productivity as well as profitability.