Soil is a non-renewable resource. Its preservation is essential for food security and our sustainable future. Graphic: FAO

By George Monbiot
25 March 2015 (The Guardian) – Imagine a wonderful world, a planet on which there was no threat of climate breakdown, no loss of freshwater, no antibiotic resistance, no obesity crisis, no terrorism, no war. Surely, then, we would be out of major danger? Sorry. Even if everything else were miraculously fixed, we’re finished if we don’t address an issue considered so marginal and irrelevant that you can go for months without seeing it in a newspaper. It’s literally and – it seems – metaphorically, beneath us. To judge by its absence from the media, most journalists consider it unworthy of consideration. But all human life depends on it. We knew this long ago, but somehow it has been forgotten. As a Sanskrit text written in about 1500BC noted: “Upon this handful of soil our survival depends. Husband it and it will grow our food, our fuel and our shelter and surround us with beauty. Abuse it and the soil will collapse and die, taking humanity with it.” The issue hasn’t changed, but we have. Landowners around the world are now engaged in an orgy of soil destruction so intense that, according to the UN’s Food and Agriculture Organisation, the world on average has just 60 more years of growing crops. Even in Britain, which is spared the tropical downpours that so quickly strip exposed soil from the land, Farmers Weekly reports, we have “only 100 harvests left”. To keep up with global food demand, the UN estimates, 6m hectares (14.8m acres) of new farmland will be needed every year. Instead, 12m hectares a year are lost through soil degradation. We wreck it, then move on, trashing rainforests and other precious habitats as we go. Soil is an almost magical substance, a living system that transforms the materials it encounters, making them available to plants. That handful the Vedic master showed his disciples contains more micro-organisms than all the people who have ever lived on Earth. Yet we treat it like, well, dirt. The techniques that were supposed to feed the world threaten us with starvation. A paper just published in the journal Anthropocene analyses the undisturbed sediments in an 11th-century French lake. It reveals that the intensification of farming over the past century has increased the rate of soil erosion sixtyfold. Another paper, by researchers in the UK, shows that soil in allotments – the small patches in towns and cities that people cultivate by hand – contains a third more organic carbon than agricultural soil and 25% more nitrogen. This is one of the reasons why allotment holders produce between four and 11 times more food per hectare than do farmers. [more]

We’re treating soil like dirt. It’s a fatal mistake, as our lives depend on it

ABSTRACT: Global demand for food is increasing in terms of the quantity, quality and reliability of supplies. Currently, over 90 % of our food is grown on (or in) a virtually irreplaceable, non-renewable natural resource – the soil. This paper examines the latest research on selected soil degradation processes (soil erosion by water, compaction, loss of organic matter, loss of soil biodiversity and soil contamination) and specifically how they impact on food production. Every year, an estimated 12 million hectares of agricultural land are lost to soil degradation, adding to the billions of hectares that are already degraded. It is estimated that soil degradation leads to a potential loss of 20 million tonnes of grain per annum, but this is likely to be an underestimate, because the evidence base is limited in identifying direct impacts of soil degradation on food production. Some soil management practices have been used to mask the effects of soil degradation on food production (e.g., additions of chemical fertilisers), but comprehensive soil conservation practices are required to respond to the multiple problems of soil degradation if the world is to be able to feed more than 9 billion people by 2050.

Input constraints to food production: the impact of soil degradation