Author(s): S. D. Gorantiwar; I. K. Smout
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Keywords: No Keywords
Abstract: This paper is concerned with the optimum utilisation of land and water resources in irrigation schemes in arid and semi-arid regions in India, which typically irrigate various crops and soils. The water available in the scheme is insufficient to meet the water requirement of all the crops grown over the entire irrigable area. Therefore a limited area is irrigated. The rotational water schedule practised in the region is based on ‘fixed interval-fixed depth’ for all crop and soil combinations (this method is locally called ‘Shejapali'). The method is easy in operation but not efficient in water utilisation. The response to the amount of water applied varies for different crops during different crop growth stages and on different soils. Therefore providing a fixed depth to different crop-soil combinations for all irrigations may not give the optimum benefit in water limiting conditions. The timing of application to different crop-soil combinations can not be varied due to operational difficulty in the rotational water schedule but the depth of irrigation can be varied at each irrigation. Therefore in this paper a ‘fixed interval-variable depth approach is suggested for such irrigation schemes. The concept of deficit irrigation is included for determination of variable depth. The practice of deficit irrigation in water limiting condition and its advantages are discussed by English and Nuss (1982), Hargreaves and Samani (1984), English (1990) and Trimmer (1990). In this paper the ‘fixed depth’approach is compared with ‘variable depth’', and their role in land and water aliocation are discussed with one case study.
Year: 1995