Managing grass

New Zealand has rye grass which grows like weed. The cows eat this grass so it is important to manage the soil and grass. Soil needs two things - phosphate and urea so fertilizers are given. Grass if grows too long ie. after 3rd leaf shoot will make the first leaf go dry and accumulate fungus which the cows hate. So if too long the farmers will cut it and accumulate the grass for the cows to eat later.