Answer:

compost

Explanation:

As it can be made synthetically or naturally it can be a compost [maybe]

and as to how it can affect the soil, for synthetic compost it can be helpful

and not a dangerous as not putting any

And as for synthetic it can be more or less productive to the plant

examples of compost is:

Autumn leaves, twigs, yard trimmings.

Grass clippings.

Vegetables and their trimmings.

Fruit and their peels.

Coffee grounds and filters.

Tea leaves and bags.

Paper napkins.

Cereal boxes.