Nitro-Chalk

An inorganic fertiliser supplying between 15.5% and 28% of nitrogen, depending upon the actual composition of the fertiliser. It is a mixture of ammonium nitrate and chalk (which is technically calcium carbonate). It produces an alkaline reaction on a turf surface and overuse can encourage earthworm activity, as well as weed and annual meadow grass invasion. A common nitro-chalk fertiliser will supply 20.5% of nitrogen and is relatively quick acting.