Agricultural lands frequently require nutrient augmentation because A) nitrogen-fixing bacteria are not as plentiful in agricultural soils because of the use of pesticides. B) the nutrients that become the biomass of plants are not cycled back to the soil on lands where they are harvested. C) land that is available for agriculture tends to be nutrient-poor. D) grains raised for feeding livestock must be fortified, and thus require additional nutrients. E) cultivation of agricultural land inhibits the decomposition of organic matter.