Using natural materials, people have manipulated the process of decomposition with compost piles and carefully placed the composted materials in their soils to increase fertility.
(people; carefully placed; the composted materials; in their soils; to increase fertility) (people; have manipulated; the process of decomposition with compost piles)
people people
carefully placed have manipulated
the composted materials in their soils to increase fertility
the process of decomposition with compost piles