they used to grow crops such as maize and other fruits
You need to specify percentage as a function of something. Examples: Percentage of total land being used for agriculture, percentage of GDP produced by agriculture, percentage of population involved with agriculture, percentage of crops which are field crops as opposed to orchard or nursery crops, etc.
It costs less to grow crops with slaves who don't have to be paid, than it does to grow crops by hiring people to work on your plantation.
carbon
It is used to grow cotton crops.
25%
It is South Carolina
It used slave labor to grow cash crops for the world market.
they used water and cow manure to fertilize the crops just right
Most of the West African farmers grow crops on community land. Villages have small land patches where anyone in the village is free to grow crops. A lot of the crops are used for subsistence.
Australia wasn't a particularly easy place to be for the settlers that came there. The climate was so vastly different from what they were used to, that they didn't know how to grow their crops and many people died to some diseases. It was very difficult for them to survive there.
They used it for water, food, and when it helped grow crops.