If you're lucky enough to have either a spring or small stream on your land you should be able to create an irrigation system for very little (or if you have the bits hanging about - for free!). We're about to apply this to a field we want to use for 2 cuts of hay this year.
1. Ability to dig a hole
2. Some 3" drainpiping
3. A 1/2" hosepipe
4. A sprinkler (optional)
To make it work:
Dig a hole big enough to maintain its integrety as a small pond adjacent to the water source at the highest point of the field to irrigate
(we're going 3m wide by 3m long depth will depend on the water prerssure wanted - 0.18 bar of pressure is made for every metre. This is equivilent to a shower on a header tank apparantly)
When you dig it create a means for the pond to drain back to it's natural course when full. Do this before you create the means for the water source to fill the hole!!
Sink the drainpipe 50 cm below the base level of the pond but keep approx 6-8" protruding from the base of the hole so it doesn't fill with mud
Attach the hose to the base of the drainpipe and run back to surface level
When you've done this fill the hole and watch the irrigation begin!
Hope it works for you!!