Disappearing Farmland

We can’t afford to lose any more farmland. Fifty years from now, every hectare of agricultural land will be crucial. Every farm that gets paved over today means that the world will support fewer people down the road.

In India, where we would expect farmland to be sacred, farmers near cities are selling off topsoil to make bricks for the booming housing market.

Developing nations simply cannot afford to sell off their future this way, just as the developed world cannot pave its way to sustainability. Agricultural land should be viewed — and treated — as a trust held by farmers today for farmers tomorrow.

Still, farms should be owned by those who work them — by people who know their land and who have a stake in improving it. Tenant farming is not in society’s best interest. Private ownership is essential — as absentee land lords give little thought to safeguarding the future.

As much as climate change, the demand for food will be a major driver of global environmental change throughout the coming decades. Over the past century, the effects of long-term soil erosion were masked by bringing new land under cultivation and developing fertilizers, pesticides and crop varieties that compensate for declining soil productivity.

However, the greatest benefits of such technological advances accrue in applications to deep, organic-rich topsoil. Agrotech fixes become progressively more difficult to maintain as soil thins, because crop yields decline exponentially with soil loss.

Coupled with the inevitable end of fossil-fuel-derived fertilizers, the ongoing loss of cropland and soil poses the problem of feeding a growing population from a shrinking land base.

Whereas the effects of soil erosion can be temporarily offset with fertilizers and in some cases irrigation, the long-term productivity of the land cannot be maintained in the face of reduced soil organic matter, depleted soil biota and thinning soil that so far have characterized industrial agriculture.

Many factors may contribute to ending a civilization, but an adequate supply of fertile soil is necessary to sustain one. Using up the soil and moving on to new land will not be a viable option for future generations.

Will modern soil conservation efforts prove too little, too late — like those of ancient societies? Or will we relearn how to preserve agricultural soils as we use them even more intensively? Extending the life span of our civilization will require reshaping agriculture to respect the soil not as an input to an industrial process, but as the living foundation for material wealth.

As odd as it may sound, civilization’s survival depends on treating soil as an investment, as a valuable inheritance rather than a commodity — as something other than dirt.

Editor’s Note: This excerpt is adapted from DIRT: THE EROSION OF CIVILIZATIONS by David R. Montgomery. Copyright 2007 University of California Press. Reprinted with the permission of the publisher.

This is the second excerpt of a two-part series. Read Part I here.