Study on feasibility of drip irrigation in shallow ground water zones of eastern India
Although the effectiveness and economics of drip irrigation systems are well established in areas having undulating topography and water scarcity, its economics in plain areas bestowed with good quality ground water at shallow depths are not yet studied. Due to this, there is confusion among farmers as well as planners regarding the guidelines for selection and propagation of this system in such areas. This study attempts to evolve guidelines for deciding the economic threshold value of fixed cost of drip irrigation system for sugarcane crop. Nomographs have been developed to find the threshold value of economic fixed cost of drip irrigation system (exclusive of pumping unit) for a combination of variables, depth of water table, yield level under check basin irrigation, expected yield gain with adoption of drip system, irrigation requirement with check basin, and electricity charges. The perusal of nomographs shows that the factors influencing the economics of drip irrigation in order of importance are yield gain ratio, electricity charges, irrigation requirement and depth of ground water.
6. Economic implications of microirrigation
The farm-level economic implications of microirrigation will vary among farms and regions, and among crops and resource endowments. Farmers producing high-valued crops in arid and semi-arid regions have a greater likelihood of gaining financially by adopting microirrigation than farmers producing low-valued crops in humid and sub-humid climates. The farm-level value of water saved by reducing irrigation requirements will vary with the cost and availability of irrigation water, and with the cost of energy and the labor required to obtain and deliver the water. Farm-level gains due to increased yields will vary with the crops produced and prices received.
Intertemporal allocation of irrigation water in the Mayurakshi Project (India): An application of chance‐constrained linear programing
This study develops an optimal cropping pattern and a reservoir management policy for the Mayurakshi irrigation project (India). Two chance-constrained linear programing models are formulated to account for the stochastic nature of the monthly inflows. The models also consider the increased economic opportunity offered by the introduction of new high-yielding crop varieties. The results clearly indicate that a change in the existing cropping pattern and reservoir management policy is desirable and is consistent with the maximization of net return to the project area. The existing supply of nitrogen fertilizer in the command area is found to be inadequate to allow the best use of other resources, including irrigation water. As the probability of occurrence of a drought or a flood is kept within a limit of 10%, the crop activities in the optimal cropping pattern suffer from drought or flood conditions no more than 10% of the time. Thus the resulting cropping patterns should be preferred by the tradition-bound farmers of the command area, who have a low risk-bearing ability.