SOIL ORGANIC MATTER Organic matter (humus), living plants, dead plants, and animal residues are a very active and an important part of soil.
(SOIL ORGANIC MATTER Organic matter (humus), living plants, dead plants, and animal residues; are; a very active and an important part of soil)
SOIL ORGANIC MATTER Organic matter (humus), living plants, dead plants, and animal residues
are
a very active and an important part of soil