Topic: Meta Analysis: Organic vs Conventional Yield

[David "Stubb" Oswald]

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11069.html

Numerous reports have emphasized the need for major changes in the global food system: agriculture must meet the twin challenge of feeding a growing population, with rising demand for meat and high-calorie diets, while simultaneously minimizing its global environmental impacts1, 2. Organic farming—a system aimed at producing food with minimal harm to ecosystems, animals or humans—is often proposed as a solution3, 4. However, critics argue that organic agriculture may have lower yields and would therefore need more land to produce the same amount of food as conventional farms, resulting in more widespread deforestation and biodiversity loss, and thus undermining the environmental benefits of organic practices5. Here we use a comprehensive meta-analysis to examine the relative yield performance of organic and conventional farming systems globally. Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak-acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable). Under certain conditions—that is, with good management practices, particular crop types and growing conditions—organic systems can thus nearly match conventional yields, whereas under others it at present cannot. To establish organic agriculture as an important tool in sustainable food production, the factors limiting organic yields need to be more fully understood, alongside assessments of the many social, environmental and economic benefits of organic farming systems.

[DK]

Nothing surprising in that report, I thought it'd had long been known that organic resulted in lower yields?

Precision agriculture, it's the only way to go.

[David "Stubb" Oswald]

They mentioned in the article that some previous studies compared properly managed organic systems to a poorly managed conventional system on bad land. They discounted these studies in their review. The only significance of this article is its the largest meta analysis to date, but yes. It confirms something we already know, not too surprising at all.

[Trinoc]

I'd like to see a similar meta-analysis comparing yield per gallon gasoline equivalent of fossil fuel used in production, to view alongside the yield per unit area of land. It seems to me that as long as non-organic farming uses something like 10-20 calories of fossil fuel energy for every calorie in the food produced it is going to become unsustainable eventually even when compared to the least efficient organic methods.

[Chew]

I'd like to see a similar meta-analysis comparing yield per gallon gasoline equivalent of fossil fuel used in production, to view alongside the yield per unit area of land. It seems to me that as long as non-organic farming uses something like 10-20 calories of fossil fuel energy for every calorie in the food produced it is going to become unsustainable eventually even when compared to the least efficient organic methods.

You might enjoy this.

[David "Stubb" Oswald]

I'd like to see a similar meta-analysis comparing yield per gallon gasoline equivalent of fossil fuel used in production, to view alongside the yield per unit area of land. It seems to me that as long as non-organic farming uses something like 10-20 calories of fossil fuel energy for every calorie in the food produced it is going to become unsustainable eventually even when compared to the least efficient organic methods.

I would to. I would like to see organic, conventional, no-till, and the like. It would be difficult though.

The most interesting thought to me about the more sustainable way to farm is the question about and use. Knowing organic can't match the yields, is it more sustainable to use more land in a system that has less of an impact per acre? Or, should we have concentrate our farm land to less area but as intense as we can get it. What is better globally?