I am having acres of land and planning to plant trees and cultivate some vegetables. I have drilled two bore-well each 400 feet depth and water at around 180 feet level. water yield was very low around 1" to 1.5". Please anyone can suggest to choose suitable bore-well pump. I am having horticulture 3 phase power connection. I am much worried about electricity bill.
Two things, since you say;Water yield is very low & Paid power connection, it makes sense to opt the minimum capacity pump that would support your depth.
If you intend to lower the pump to 380ft, you would probably need a 3hp but if you lower the pump to lets say less than 300ft, 2Hp would do the job.
Also, if you are drip irrigating, sometimes the lower capacities dont support the high pressure head and you might then need to consider higher capacities.
Hope this helps!