Professor Mary Scholes and Dr Bob Scholes who have published a paper in the journal Science, which describes how the productivity of many lands has been dramatically reduced as a result of soil erosion, accumulation of salinity, and nutrient depletion.

It’s not a crystal ball thing; great civilizations have fallen because they failed to prevent the degradation of the soils on which they were founded.  Our modern world could suffer the same fate.

Mary Scholes, who is a Professor in the School of Animal, Plant and Environmental Sciences at Wits University said, “Cultivating soil continuously for too long destroys the bacteria which convert the (crop) organic matter (back) into nutrients.”

Mary Scholes a Professor at Wits University. Click image for the largest view.

Mary Scholes a Professor at Wits University. Click image for the largest view.

Improved technology – including the unsustainably high use of fertilizers, irrigation, hybrid plants and engineered genetics applied to marginal land provides a false sense of security.  Most worrisome is about 1% of global land area is degraded every year. In Africa, where much of the future growth in agriculture must take place, erosion has reduced yields by 8% and nutrient depletion is widespread.

Factually the very best land that’s found Iowa, southern Minnesota, Western Wisconsin, northern Illinois of North America and the Ukraine of Eastern Europe are very small areas.  The rest of the arable land in use is only a marginal quality of these top soils.

Bob Scholes, who is a systems ecologist at the Council for Scientific and Industrial Research said, “Soil fertility is both a biophysical property and a social property – it is a social property because humankind depends heavily on it for food production.”

Soil fertility was a mystery to the ancients. Traditional farmers spoke of soils becoming tired, sick, or cold.  The solution was typically to move on until they recovered.  By the mid-20th century, soils and plants could be routinely tested to diagnose deficiencies, and a global agrochemical industry set out to fix them. Soil came to be viewed as little more than an inert supportive matrix, to be supported with an annual dose of nutrients.

This narrow approach works up to the point when fertility becomes uneconomic.  For now it has led to an unprecedented increase in food production, but also contributed to the pollution of aquifers, rivers, lakes, and coastal ecosystems. Activities associated with agriculture are currently responsible for just under one third of the alleged greenhouse gas emissions; more than half of these originate from the organic decomposition of the remaining crop stems leaves, straw and other parts.

Replacing the fertility-sustaining processes in the soil with a dependence on external inputs has also made the soil ecosystem, and the social civilizations as we know them, vulnerable to interruptions in the supply of those inputs, for example, price shocks or transport problems.

The hard reality for the green folks is it is not possible to feed the current and future world population with a dogmatically “organic” approach to global agriculture. Given the large additional area it would require, such an approach would also not avert greenhouse gas emissions, spare biodiversity, or purify the rivers.  Plus the labor and mechanical intensity would drive food prices far higher.

The scientists make a case that to achieve lasting food and environmental security, we need an agricultural soil ecosystem that more closely approximates the close and efficient cycling in natural ecosystems, and that also benefits from the yield increases made possible by biotechnology and inorganic fertilizers.

The research makes clear the common sense concept that caring for the land is the key to food and biofuel production.  The history is clear, the markets of today are for now just a reflection of technology’s gains, there is a true limited resource at risk.

Unlike oil, natural gas and coal where the “peak oil’ idea came and went, for food and biofuels there is no more land to find.

For now the major food products like wheat, soya and corn are in great supply and prices have fallen about a third this year. (For the food vs fuel debate – have your grocery bills gone down a third as well?)

The thing to watch for over the coming years is the lowest quality marginal land becoming incapable of supporting intense food and fuel production at economic levels.  Worldwide much of the very low quality land has been brought under cultivation at great fertilizer and nutrient expense supported by the past few years’ high prices.

We’re headed for a roller coaster ride on prices of the major farm commodities in the coming decades as the economics of high production costs of marginal land compete in a world market.  The reality is the lowest marginal lands will become useless and the land areas lost will increase each year.  Over time the lost land will have been of better quality accelerating the problem.

Genetic engineering will buy some time, but there is major resistance now that may increase before the hard lesson must be learned.


1 Comment so far

  1. Matt Musson on November 7, 2013 6:38 AM

    It has been my experience that for salty and compacted soils – the Medina Soil Activator from Medina Ag in Hondo Texas does the trick. It basically encourages biological activity in the soil by 2000%. They have some very impressive experience dealing with salt in post-hurricane fields.

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