The three types of rocks igneous, sedimentary, and metamorphic are all subject to processes that change one rock type into another. The images below show several types of rocks undergoing these processes.
Lime is a soil amendment made by grinding limestone, a naturally occurring type of rock that is very high in calcium. Two types of lime are commonly used in lawns and gardens, agricultural lime and dolomitic lime. Agricultural lime, also sold as garden lime, is made from calcium carbonate.
Many homeowners are trying out organic lawn care practices. Using compost to fertilize turf is one option for earth-friendly lawn care. The nitrogen that compost supplies to a lawn becomes available to grass roots slowly, which helps avoid heavy nitrogen leaching.