Sunday, November 22, 2009

Modern Agriculture

by Richard Crews
In recent years there has been a "return" to some long-lost farming practices such as "no-till farming."

Tilling is used to remove weeds, mix in soil amendments like fertilizers, shape the soil into rows for crop plants and furrows for irrigation, and prepare the surface for seeding. This can lead to unfavorable effects, like soil compaction; loss of organic matter; degradation of soil aggregates; death or disruption of soil organisms including mycorrhiza, arthropods, and earthworms; and soil erosion where topsoil is blown or washed away.

Throughout the world not only numerous small farms but also vast agricultural tracts have been converted to no-till farming in the past couple of decades. It requires less financial input than tilling, can maintain profits, and reduces the strain and drain on the ecosystems in which the farming is embedded.

Beyond no-till farming is "conservation agriculture." Conservation agriculture has three general approaches:

The first is practicing minimum mechanical soil disturbance (no tilling) which is essential to maintaining minerals and diverse organisms within the soil and limiting water loss.

The second involves managing the topsoil to create a permanent organic soil-cover mulch that can allow for growth of organisms within the soil structure. This layer of organic matter prevents soil erosion, stabilizes moisture and temperature levels, and acts as a fertilizer for the soil surface.

The third is the practice of crop rotation (with more than two crops). This prevents insect and weed pests from getting established in a rotation with specific crops. Thus it acts as a natural insecticide against destructive pests, and herbicide against specific weeds. Crop rotation can also help build up the soil's infrastructure and the build up of rooting zones which allow for better water infiltration.

A fourth practice that follows naturally from these three general approaches is the use of minimal or no chemical fertilizers and pesticides. These are expensive and unnecessary. But more than that they distort natural ecological processes and balances, and they run off fields to contaminate waterways.

Finally, in conjunction with no-till and conservation agriculture seed selection from year to year can produce increasing yields and increasingly drought- and pest-resistant strains. This has also been practiced for thousands of years since the dawn of agriculture, but modern knowledge of genetics and seed-incubation practices can enhance the effectiveness of selective breeding enormously.

Regarding GM: The process of genetic modification of seed stock has come into public focus in recent years. Lay pundits fear inadvertent poisoning and new waves of allergies, industrial market manipulations (e.g., by Monsanto) have distorted economic practices, and--until recently--there has been little good news to show for the expensive scientific efforts. I say "until recently" because of new reports that soybeans have been genetically altered to produce poly-unsaturated fatty acids. These are essential nutrients in the human diet and have previously only been available from fish oils--salmon have particularly taken a severe threat-of-extinction hit. GM is a new science; it has produced careless and overenthusiastic technologies. And GM has not thus far produced the miracles predicted for it, but with care and patience it may well make significant contributions to agriculture and to feeding the hungry of our increasingly overpopulated and farming-exhausted world.