Our Indispensable Soil - Soil: Reflections on the Basis of our Existence - page 19

More with less. Biodiversity increases if we farm organically and avoid pesticides and artificial
fertilisers. Poppies and cornflowers can survive on field margins, while grass and other species
that benefit from nitrogen-rich artificial fertiliser become less dominant
provides excellent fodder but also fertilises the soil with nitrogen-fixing plants like
clover. The roots of clover and other plants can fix several hundred kilograms of
nitrogen per hectare. The findings of a major Swiss study comparing the environ-
mental consequences of conventional agriculture with organic farming are une-
quivocal: over a period of twenty years, organic farming led to more fertile soil
with a superior structure, higher humus content and greater diversity of plants
and terrestrial animals than conventional farming. On the other hand, crop vol-
umes were on average one fifth lower on organic farms. Potatoes fared especially
badly in the study, with blight causing major losses. Potato blight caused the Great
Famine in Ireland in the mid-nineteenth century and potato growers have yet to
find a silver bullet. Some strains of potato developed to be resistant to blight have
later lost their immunity.
Organic farming involves the sustainable use of resources. But the fact remains
that were it not for artificial fertiliser, the global population would be much lower
than it is today. There is a broad consensus that the number of people on the planet
will stabilise at around nine billion by 2050. If we are to feed all these mouths, we
will need to use all the means at our disposal to increase world food production.
But over-intensive agriculture causes serious problems. Western countries
import animal feed made from soybeans grown in vast monocultures in coun-
tries like Brazil. Since monocultures are vulnerable to disease, the crops must