According to me Center pivote ...

According to me Center pivote is the answer

For adapting best suitable Irrigation method, one must know the advantages and disadvantages of the various methods.one must know which method suits the local conditions best. Unfortunately, in many cases there is no single best solution: all methods have their advantages and disadvantages. Testing of the various methods - under the prevailing local conditions - provides the best basis for a sound choice of irrigation method.

The suitability of the various irrigation methods, i.e. surface, sprinkler or drip irrigation, depends mainly on the following various factors like natural conditions, type of crop, previous experience with irrigation, required labour inputs and costs and benefits. Like in your case Clay soils with low infiltration rates are ideally suited to surface irrigation. When a variety of different soil types is found within one irrigation scheme, sprinkler or drip irrigation are recommended as they will ensure a more even water distribution. Sprinkler or drip irrigation are preferred above surface irrigation on steeper or unevenly sloping lands as they require little or no land leveling.

Surface irrigation often requires a much higher labour input - for construction, operation and maintenance - than sprinkler or drip irrigation. But as you have mentioned you have less man power availability. So as per my suggestion the center pivot is the system for you because of its low labor and maintenance requirements, convenience, flexibility, performance and easy operation. Calculations for the pivot can be made according to the requirement. Generally every manufactures provides that after understanding your field condition.