How productive is organic farming?

Those who argue for conventional agriculture from an ideological as opposed to science-based standpoint may find the answer to this question rather inconvenient.

Conventional wisdom is that the use of inorganic fertilisers and pesticides boosts crop yields beyond what is achievable with purely organic systems, and that their use is required if we are to feed a rapidly growing world population. The argument is usually tied-in with that over genetic engineering, and this is unfortunate as it implies a polarisation of opinion between “green” and “brown” approaches to agriculture.

As for the real world, agronomists Josh Posner, Jon Baldock and Janet Hedtcke at the University of Wisconsin have analysed results from the Wisconsin Integrate Cropping Systems Trial, and found that organic systems can be as productive as their conventional counterparts. In a recent paper the researchers say that this is so always for alfalfa and wheat, and most of the time for corn and soybeans. Organic forage crops yield as much or more dry matter than conventional, and organic winter wheat produces 90% as much as that grown using inorganic inputs.

That said, there are some unanswered questions regarding the applicability of the results to climatic conditions different from those of the US prairies, and more research is needed.

“There continues to be improvements in weed control for organic systems that may close the gap in productivity of corn and soybeans in wet seasons,” says Posner. “On the other hand, technological advances may accelerate productivity gains in conventional systems that would outstrip the gains in organic systems even in favorable years.”

This is an interesting analysis, and I have no axe to grind when it comes to organic versus conventional agriculture. I tend not to buy organic food owing to the often exorbitant prices charged, and I do not accept the claims of organic food lobbyists that organic is always the healthier option. Of more interest to me are issues such as local production, processing and distribution, vested interests and control over the world food market.

If the Wisconsin analysis is confirmed by further studies, then I would hope that the debate over agriculture, food and the environment can move on.