Instead, organic agriculture uses crop rotation, the growing of different crops than cotton in alternative years.
Because both the world population and the intensive agriculture used to support it are growing, ammonia demand is growing.
Peruvian agriculture uses synthetic fertilizers rather than the still-abundant guano due to infrastructure issues.
Incan agriculture used the chakitaqlla, a type of foot plough.
Increasingly, agriculture is using untreated wastewater for irrigation.
By contrast, slash-and-burn agriculture uses ashes from burned forests as fertilizer.
Since agriculture uses such an enormous quantity of water, conserving even a small portion of it can meet a large share of new urban needs.
All agriculture must use irrigation; there is no dryland agriculture.
Such agriculture of course used more water.
Increasingly, agriculture is using untreated wastewater as a source of irrigation water.