- Role of indigenous foods in addressing malnutrition and diet-related diseases in Africa: a systematic review. Traditional foods contribute to dietary diversity, micronutrient intake and food security. Nutrition policy should pay more attention to what people used to eat.
- Regenerative agriculture for dietary diversity and food security in Zambia. Soil-focused regenerative practices are associated with more diverse diets, through a mixture of production, income and market effects. Soil health has a dietary dimension.
- The Relationship among Food Environment Types, Diet, and Nutrition Outcomes in Women, Children, and Adolescents from Low- and Lower-Middle Income Countries. What surrounds people matters as much as what they grow: food environments influence dietary diversity and nutrition in complicated ways, but access to wild foods is usually a good thing.
- Allele-specific expression reveals complex regulatory divergence underlying fruit phenotypic differences between cultivated and wild tomato species. Wild tomato relatives harbour genetic variation for sugars, volatiles and other flavour traits that domestication left behind. A reminder that “improvement” can be a process of subtraction. Not nutrition you say? I bet flavour is connected with nutrition — in complicated ways.
- Large-scale phenotyping and multi-trait selection identify low-methane Napier grass accessions under contrasting environmental conditions. Napier grass accessions differ substantially in methane yield, digestibility and other traits. Feed diversity could help reduce livestock emissions without sacrificing everything else. Cows need better nutrition too.
Two legends of agricultural transformation
Land sparing is a seductive story.
Farmers become more productive. We need less land to produce the same amount of food. The land we no longer need can be spared for nature. No need for that tricky land sharing business. Everybody wins.
A new paper in Agriculture and Human Values calls this a “policy legend”: a complicated and contested body of research gets turned into a simple, reassuring story about technology and intensification. The politics of who owns land, who benefits from intensification, what gets produced and where, and what happens to rural livelihoods very conveniently disappear from the equation.
But the other side of the debate has its own temptations. Agroecology as a movement is often explicit about context, politics and food sovereignty. Yet it too can occasionally shrink to something that’s cosily tidy: conventional agriculture is the problem, agroecology is the solution, here are some desirable practices, get farmers to switch.
Another new paper, this one in Ecological Economics, also makes that story look way too simple. And you know how we love that here. The authors look at 2,721 farms in six African countries and find very different starting points for the transition to agroecology, and different trajectories. The smallest farms tend to combine autonomy and income diversification; larger farms more often go for some crop-livestock integration; small and medium farms may put more land into legumes for soil health.
I guess we shouldn’t be surprised. The way farmers make decisions is complicated. And I coincidentally came across a study in Food and Nutrition Bulletin that illustrates that rather well, albeit on a small scale. Surveys of 26 farmers in the Ecuadorian highlands found that they grew diversity for economic reasons, sure, but also for social, emotional or health and safety reasons. And, rather wonderfully, sometimes simply because they liked it.
Farm size, labour availability, markets, tenure, risk, access to inputs, knowledge, household objectives and yes, sheer aesthetics, all shape what farmers can do, are willing to do, and indeed eventually end up doing. Change one part of the system, and you can change the economics of the rest.
So why do we keep reaching for legends?
Simple stories are useful, I guess. They fit snugly into funding proposals, policy briefs and campaign slogans, and every camp needs something to organise around. Unfortunately, agriculture is way messier than the legends we tell about it.
Where have all the nutrients gone?
The “nutrient collapse” story has been doing the rounds for years, and we’ve been picking at it on the blog for almost as long.
Back in 2009, Jeremy looked at evidence that older crop varieties could contain more minerals, protein and other nutrients than newer ones, and discussed various possible reasons, including the intriguing possibility of a “genetic dilution” effect as breeders selected for yield.
By 2012, we were stressing that the evidence was more complicated than the headlines suggested, and in 2019 we linked to the latest critical review of the evidence by Robin Marles of the Bureau of Nutritional Sciences in Canada.
Now the latest episode of the BBC’s indispensable More or Less podcast asks again whether carrots are becoming less nutritious, prompted by a listener who clearly hasn’t been following our blog, and turns to Dr Marles, now retired, for the answer. Which hasn’t really changed much.
The bottom line is that breeding for yield and other commercially important traits can change the balance of what ends up in the harvest, and that we have historically been much better at measuring tonnes per hectare than what is actually in those tonnes.
Organic roundup
I could have sworn I had at least Nibbled Our World in Data’s Is organic farming better for the environment than conventional farming? But it doesn’t look like it. Fortunately, Jeremy gets to grips with it in his latest newsletter. Along with that autumnal favourite, the apple, and lots of other interesting stuff.
Brainfood: Biodiversity works through relationships
- Plant diversity modifies multi-trophic interactions in croplands, grasslands and forests. Increasing plant diversity changes the interactions between plants, herbivores and their natural enemies, but exactly how depends on the ecosystem. Diversification’s pest-suppression magic looks like a farming-specific trick, not a universal law.
- High-resolution carbon and biodiversity mapping shows correlated losses across space and agricultural products. Carbon loss and biodiversity loss from farming turn out to hit the same ground: two-thirds of both concentrated on one-third of agricultural land, with beef and milk alone responsible for 41% of the biodiversity damage. Good news for anyone hoping one policy lever could do double duty.
- Harnessing agri-food system microbiomes for sustainability and human health. Soil to gut, it’s all one network, linking ecosystem function, food production and human health across the entire agri-food system.
- Breeding for beneficial microbial associations. If microbiomes matter that much, why not breed for them? A proposed framework pairs crop traits that recruit good microbes (root exudates, architecture) with soil practices that keep those microbes around, since good genetics on ruined soil gets you nowhere. This means designing crops as participants in ecological networks rather than as isolated organisms.
- Host genetics and social relationships jointly shape fitness-associated microbiome variation in a population of feral horses. Nature’s own microbiome-breeding program: seven years of horse poop from Sable Island shows gut microbes predict winter survival, and related horses share microbes more than chance allows. So the functional unit of adaptation is the animal plus its microbiome.