Organic farming can feed the world if done right
New study suggests chemical fertilisers are not so vital
Organic farming is much more productive than previously thought,
according to a new analysis of agricultural studies that challenges the
conventional "biased" view that pesticide-free agriculture cannot feed
the world.
The study says that organic yields were only 19.2 percent lower, on
average, than those from conventional crops and that this gap could be
reduced to just eight per cent if the pesticide-free crops were rotated
more frequently.
Furthermore, in some crops - especially leguminous plants such as
beans, peas and lentils - there were no significant differences in
yields, the researchers from the University of California, Berkeley
found.
"In terms of comparing productivity among the two techniques, this
paper sets the record straight on the comparison between organic and
conventional agriculture," said Claire Kremen, professor of
environmental science, policy and management at Berkeley.
The study comes amid rising concerns that intense farming practices
are damaging the environment, with the widespread use of nerve agent
pesticides frequently blamed for declining populations of bees and other
pollinators.
Fertilisers are producing smaller and smaller increases in yields
because they are now so effective they are difficult to improve upon..
"With global food needs predicted to greatly increase in the next 50
years, it's critical to look more closely at organic farming because,
aside from the environmental impacts of industrial agriculture, the
ability of synthetic fertilisers to increase crop yields has been
declining," said Prof Kremen.
The researchers based their findings on a meta-analysis of 115
studies - a dataset three times greater than any previous such paper -
comparing organic and conventional agriculture.
In addition to finding a smaller - 19.2 per cent - productivity
difference between the two than previously calculated, the researchers
also found that optimising organic productivity through different
techniques could further reduce the gap.
Multi-cropping, or growing several crops together on the same field,
would cut the yield difference to nine per cent, with crop rotation
reducing the gap to eight percent.
The study suggested that the gaps could be even smaller than they
have calculated because existing studies were "often biased in favour of
conventional agriculture".
"Our study suggests that through appropriate investment in
agroecological research to improve organic management and in breeding
cultivars for organic farming systems, the yield gap could be reduced or
even eliminated for some crops or regions," said the study's lead
author, Lauren Ponisio, a graduate student in environmental science,
policy and management.
The researchers suggest that organic farming can be a very
competitive alternative to industrial agriculture when it comes to food
production.
"It's important to remember that our current agricultural system
produces far more food than is needed to provide for everyone on the
planet," said Prof Kremen.
"Eradicating world hunger requires increasing the access to food, not
simply the production. Also, increasing the proportion of agriculture
that uses sustainable, organic methods of farming is not a choice, it's
a necessity. We simply can't continue to produce food far into the
future without taking care of our soils, water and biodiversity," she
said.
- The Independent
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