i wonder where some of you get your ideas from
buttercups are a sign that the ground is needing lime
clover this is a plant that any good farmer wants yes it draws nitrogen from the air and stores it in its roots and benefits the grasses that are growing phosphate and potash help it to grow nitrogen or straight nitrogen kills of every thing through time and costs a fortune as well
geese is that domestic as opposed to wild geese i would not want thousands of them landing shitting all over the grass
if you are hell bent on getting rid of buttercups and clover spray with roundup or deep plough and reseed with what ever grass seed variety that you fancy
personally i would just lime it you can get pelleted lime that you can apply with a fertilizer distributor