Above Ground…
Grass plants are 70 to 80% water
Grass clippings are 90% water
Grass clippings contain 4% nitrogen, 2% potassium and 0.5% phosphorus

A 10,000 square foot lawn will contain:
6 grass plants per square inch
850 plants per square foot
8.5 million plants total

Below Ground…
90% of the weight of grass is in its roots
A single grass plant has 387 miles of root
There are 329,000 miles of root per square foot
3 billion miles of roots in a 10,000 square foot lawn
Turfgrass sod is a superior form of erosion control, with tests documenting:
A dense lawn is 6 times more effective than a wheat field and 4 times better than a hayfield at absorbing rainfall.
Sediment losses from sodded areas will be 8 to 15 times less than for tested man-made erosion control materials and 10 times less than for a straw covered area.
Runoff from a sodded area will take 28 to 46 times longer than for five popular erosion control materials.
* A 50 by 50 foot lawn (2,500 square feet) releases enough oxygen for a family of four, while absorbing carbon dioxide, hydrogen fluoride and perosyacetyle nitrate.