The time is right to make the transition from a staple grain processed agricultural system to an agricultural system that promotes diversity, nutrition, increased wealth, growth in incomes, through diversity and increase in high-value crops.
Nice to hear that, from Prabhu Pingali no less, director of the Tata-Cornell Institute for Agriculture and Nutrition at Cornell University, as part of an IFPRI special policy seminar: Tales of yield improvement and farewell to Mark Rosegrant.
Especially as a recent meta-analysis of the association between production diversity, dietary diversity and nutritional outcomes found an inconsistent picture:
but not surprising. "V effective in most situations" is high bar. Quite effective in some is more likely. Just have to find right situations
— Lawrence Haddad (@l_haddad) April 26, 2018
An example is the CCAFS study in Africa, which found that more diverse households and farming systems are more food secure, but only up to a point, and the association depends on a number of other, interacting factors.
As Lawrence Haddad so wisely says in his tweet above, you have to find the right situation. That may be complicated, but still worth doing.
It is nice to see this important study. It found an overall positive, but weak effect of crop/animal species of diet diversity at household level: 16 species are needed to increase the number of food groups by 1.
But that finding cannot be translated directly into policy. The abstract seems to suggest this mental shortcut. But that supposes a random selection of species for interventions. Most policy makers will be better than random (I would think) when they suggest new species to be included, focusing especially on those that are currently not represented in the diets or that would become more general if the price would go down. Studies that look at well-designed diversification interventions specifically aiming at nutrition would be needed to get a more realistic number.
The other limitation of the study, which is pointed out by the authors as well, is the unit of analysis, the household. More studies are needed to evaluate if species diversity increases diet diversity at other scales. After all, to increase diet diversity, someone has to produce this diversity and there are transport costs and limitations that will constrain exchange in markets. So not only what the household produces itself, but also what neighbours produce will be important. Producing 16 species on a single farm is extremely difficult. But knowing five neighbours who each can each sell a unique species to you (or barter) is much easier to achieve. I would be surprised if the nutritional effect of diversification would depend much on what households produce themselves, as specialization is often a good strategy at household level. So the fact that there is a positive link (on average) is already encouraging.
We need a new generation of studies that looks at the effects of diversification on nutrition with a broader perspective on the candidate mechanisms for this link.
“Good market access allows farmers to specialize on the production of the most profitable crops, including nonfood
cash crops, leading to income gains and improved ability to purchase healthy diets.”
It always puzzles me why farmers are expected to eat everything they produce – and nothing else – to have a good diet (as the above quote from the review indicates is not so). Farmers here in Scotland have pasture for beef, seed potatoes (both for export down south and beyond), and then barley (for whisky and feed-stuff) and oil seed rape and rarely anything else. They go supermarket shopping like the rest of us and seem to be healthy.