soil

Here is David Montgomery writing in his "Dirt, the Erosion of Civilizations" in 2007.  He says it well:

"The philosophical basis of the new agriculture lies in treating the soil as a locally adapted biological system rather than a chemical system.  Yet agroecology is not simply a return to old labor intensive ways of farming.  It is just as scientific as the latest genetically modified technologies-but based on biology and ecology rather than chemistry and genetics.  Rooted in the complex interactions between soil, water, plants, animals and microbes, agroecology depends more on understanding local conditions and context than on using standardized products or techniques.  It requires farming guided by locally adapted knowledge-farming with brains rather than by habit or convenience.

Agroecology doesn't mean simply going organic.  Even forgoing pesticides, California's newly industrialized organic factory farms are not necessarily conserving soil.  When demand for organic produce began to skyrocket in the 1990's industrial farms began planting monocultural stands of lettuce that retained the flaws of conventional agriculture-just without the pesticides."

There it is!  The argument for people on the land we have been looking for and from the words of an observant geologist.