What a fabulous time of the year to appreciate more green in our yards and gardens! I prefer to call a little patch of clover in my yard shamrocks, although I'm not entirely sure if it's the precise variation of clover that it appears to be. It happened to be growing naturally in part of the garden bed that I wanted to prepare for planting. So, some shamrocks became green manure for the garden.
I was turning under the area by hand with a spade, because we don't own a large tiller. The more I read about modern gardening techniques, it seems like less tilling is better for soil preparation, so I won't worry about not having a mechanized device. You may know that gardeners consider cover crops such as clover to be rich sources of nitrogen.
My use of green manure was very simple in this case. Yet, some gardeners and farmers intentionally plant certain green manures or cover crops to enrich the soil, prevent erosion and control weeds. So there you have it: shamrocks as green manure, nature's nitrogen boost. A humble use for the famous little plant that we celebrate in March.