Yes Tress lucerne is an excellent legume for the soil as is red...

Yes Tress lucerne is an excellent legume for the soil as is red clover with very little need to add nitrogen once established. I use potash to fertilise paddocks
Lucerne as a living mulch is an excellent source of nitrogen vitamins and minerals
As dry mulch it has nirogen fixation qualities which i didn't realise, although not sure of the amount of nitrogen
it contains.
Often you can purchase 3 bales of pasture hay to one lucerne price wise depends on your budget and size of garden.
A neighbour up the road has 5000 lemon trees and bales his own pasture hay for mulch as lucerne is to dear.
Pasture hay for sale $5 a bale ex Wauchope....
Thanks for the tip!