<P> Panorama of a natural wetland (Sinclair Wetlands, New Zealand) </P> <P> Food is any substance consumed to provide nutritional support for the body . Most food has its origin in renewable resources . Food is obtained directly from plants and animals . </P> <P> Hunting may not be the first source of meat in the modernised world, but it is still an important and essential source for many rural and remote groups . It is also the sole source of feeding for wild carnivores . </P> <P> The phrase sustainable agriculture was coined by Australian agricultural scientist Gordon McClymont . It has been defined as "an integrated system of plant and animal production practices having a site - specific application that will last over the long term". Expansion of agricultural land reduces biodiversity and contributes to deforestation . The Food and Agriculture Organisation of the United Nations estimates that in coming decades, cropland will continue to be lost to industrial and urban development, along with reclamation of wetlands, and conversion of forest to cultivation, resulting in the loss of biodiversity and increased soil erosion . </P>

Organic matter in soil is also called answers.com