Agricultural Biodiversity Weblog

April 23, 2026April 23, 2026

A mycelial thread through human history

A very interesting review in New Scientist makes the point that fungi were not for ancient humans the marginal resources that their near invisibility in the traditional archaeological record might suggest. In fact, they contributed to diets, health and social organisation, and even fire-making. Here’s a quick summary of what new analytical techniques in archaeology, sometimes linked with ethnography, are revealing, according to the article.

Fire technology (Mesolithic to Neolithic): Polypore fungi, especially Fomes fomentarius, were deliberately harvested, cut, scorched and processed into amadou. This is a felt-like, highly flammable material that people used as portable tinder, forming compact fire-starting kits together with birch bark and pyrite.

Food (Palaeolithic, including Neanderthals): Evidence from dental plaque DNA shows consumption of multiple species (e.g. gray shag, split gill, porcini), suggesting diets were more diverse than has been assumed. Mushrooms may partially explain isotopic signals previously attributed to meat consumption.

Medicine: A Neanderthal individual consumed grasses containing penicillin-producing mould, possibly to treat a dental abscess. Later, Ötzi the Iceman (~3300 BCE) carried amadou, but also birch polypore mushrooms. These may have had medicinal purposes (anti-parasitic, antimicrobial), though they were not found in the stomach, so a new hypothesis suggests they may have been used as fishing floats, based on morphology and experimental replication.

Subsistence and resource extraction: Polypores and puffballs may have been burned to produce smoke to anaesthetise bees, making harvesting honey a lot easier.

Fermentation (Neolithic): Moulds such as Monascus enabled enzymatic conversion of rice starch to sugars, facilitating alcohol production by the so-called “red qu” method. Pottery residues in East Asia show evidence of such brewing some 10,000 years ago, much earlier than originally thought. Fermented beverages were likely used in ritual, mortuary, and communal contexts and may have contributed to social cohesion, identity formation and early political and religious structures.

April 22, 2026April 23, 2026

The seeds of tropical fodder grass development

Usually, if plant breeders do anything at all with wild species, they use them to try to improve the domesticated relative in some way. But in Bajra–Napier Hybrids (BNH), it’s actually the crop that is used to improve a wild (or at least wildish) relative.

That’s more than just a fun fact. BNH are actually pretty important forages in tropical and subtropical livestock systems, though you don’t hear too much about them other than from specialists. I certainly hadn’t, until a recent social media blitz from ICRISAT.

They are made by crossing the crop pearl millet (bajra, Pennisetum glaucum) with the related forage Napier grass (Pennisetum purpureum). This has the effect of combining nicely complementary traits into a highly productive fodder plant.

The best thing about BNH is their high yield of biomass. Under ideal conditions, annual green fodder production can exceed 200–300 tonnes per hectare, which comfortably outperforms other forage grass options. This productivity is due to fast growth, profuse tillering, and efficient nutrient uptake. For smallholder dairy systems, where land is usually at a premium, such a yield advantage translates pretty quickly into higher milk output per area. Also, BNH are perennial, which reduces costs over time, as fields can remain productive for several years with proper care.

And the nutritional profile of the fodder is pretty good. Crude protein is typically 8–14%, depending on management and cutting stage, while digestibility remains ok if the plants are harvested relatively early, before they start getting woody, say at 45–60 day intervals.

BNH are resilient, being tolerant to drought and intermittent water stress, a trait inherited largely from pearl millet, though they also respond well to irrigation and fertilization. That makes them widely suitable, everywhere from low-input rainfed systems to intensive peri-urban dairying.

All that said, there are drawbacks. Perhaps the main one is that BNH are typically sterile, not producing seeds, and therefore have to be propagated vegetatively, through stem cuttings or root splits. This means farmers depend on planting material supply chains that are often weak or informal. Diseases can also be transmitted more easily via vegetative material. Plus high biomass production demands big nutrient inputs, particularly nitrogen, with inadequate fertilization quickly eroding both yield and quality. That can be expensive.

In response, an important recent line of research has focused on developing seed-propagated BNH. Seeds simplify dissemination, reduce transport costs, and mitigate the spread of vegetatively transmitted diseases. They also enable more formal seed sector engagement, including developing new varieties.

Making fertile hybrids is technically tricky. Sterility in the classic hybrids is due to genomic incompatibilities between the parental species, basically their different ploidies, or numbers of chromosomes. So breeding strategies have explored chromosome doubling, intermediate ploidy levels, and backcrossing to restore partial fertility while retaining the desirable forage traits.

This has been reasonably successful, but trade-offs remain: some seed-propagated lines show lower biomass yields or less persistence compared to established clonal hybrids, and ensuring consistent performance across environments is still a work in progress. So it’s good to see ICRISAT and its partner still on the case, hard at work.

ICRISAT is advancing forage research with trials on seed-propagated Bajra–Napier Hybrids (BNHs) a shift from traditional stem cuttings to a scalable, seed-based approach.

Bajra–Napier, a key fodder crop for dairy systems, combines the high yield and perennial nature of Napier… pic.twitter.com/kKBQ58IuIn

— ICRISAT (@ICRISAT) April 20, 2026

LATER: Dr Chris Jones, program leader for feed and forage development at ILRI, who should know, tells me that the currently accepted names for the parents of BNH are Cenchrus americanus (pearl millet) and C. purpureus (Napier grass). Something to do with Cenchrus being nested within Pennisetum evolutionarily speaking, so the best bet was to merge the genera, but under the name Cenchrus because that is the older one.

April 20, 2026April 20, 2026

Brainfood: Animal diversity edition

Livestock grazing boosts plant diversity in the Greater Serengeti–Mara Ecosystem. Livestock can be good for biodiversity conservation. But can its diversity be conserved too? Let’s see.
Conservation and Management of Animal Genetic Resources in the Context of African Livestock Production Systems: The Case for In Situ and Ex Situ Conservation. “The multi-stakeholder breeders-researchers-decision-makers approach remains the most robust solution for sound management and preservation of biological units.” What, no farmers and local communities? No, that’s unfair: community-based conservation is discussed. But it doesn’t feel as central to the whole thing as it should be, somehow.
Genetic Diversity, Adaptation, Wild Introgression, and Coat Color Mutation of Golden Yak. After all, local communities have maintained the golden yak reasonably well.
Caprine dairy exploitation on the Iranian Plateau from the seventh millennium BC. Not to mention goats in Iran, and for thousands of years…
Old goats: 3,000 years of genetic connectivity of the domestic goat in Ireland. …and in Ireland, though for not quite as long, admittedly.
Dogs were widely distributed across western Eurasia during the Palaeolithic. And local communities have been managing dog populations since way before farming even.
The dispersal of domestic cats from North Africa to Europe around 2000 years ago. Also, local communities managed early cats separately in the Levant and Egypt. Much later than dogs, but that’s cats for you.
A microbiome catalog of Chinese traditional artisanal cheeses provides insights into functional and microbial diversity. And don’t forget to conserve the associated microbiome too. I wonder what golden yak cheese is like.

April 19, 2026April 20, 2026

We need diverse farms, and genebanks can help

A LinkedIn post by CGIAR stalwart Dr Carlo Fadda convinced me I should give a bit more exposure to a recent paper than the brief Brainfood entry I wrote about it a few weeks ago. The paper is Long-term agricultural diversification increases financial profitability, biodiversity, and ecosystem services: a second-order meta-analysis. Its authors are Estelle Raveloaritiana and Thomas Cherico Wanger, and it was published in Nature Communications this past January.

In that Brainfood, I tried to bring together in a logical thread various studies on different aspects of farm diversity and its benefits. In particular, its effects on diet diversity, and hence health outcomes.

But better diets and human health are not the only pluses of diverse farms, and the paper in question in fact suggests that intercropping, organic farming, and other diversification strategies also increase incomes, biodiversity, pollination, soil quality, and carbon sequestration significantly over 20 years. With, importantly, no downward hit on crop yields. So going diverse — organic, if you will — has many advantages that are not overall associated with a yield tradeoff. And that’s from a meta-analysis of 184 meta-analyses and 120 years of data, so it’s a pretty robust result.

As Dr Fadda points out in his excellent summary of the paper, good evidence that diverse — including agrobiodiverse — farms are good for farmers, consumers and the planet is clearly there. The challenge is to find the institutional will to act on it.

I’d like to add that genebanks around the world are ready, willing and able to do just that. It’s literally their job, or at least a big part of it. I hope they are given the chance — and the resources — to do it.

April 14, 2026April 13, 2026

Yes, win-win-win diets are possible

Happy to second the sentiment expressed in this snippet from Jeremy’s latest newsletter. And there are so very many more equally interesting snippets to be found across the previous 299 issues, going back almost exactly 11 years. Congrats, Jeremy!

I heartily applaud scientists who take the trouble to create a more accessible version of their research results, and not only because it saves me the effort. I’m very happy, then, to refer you to two versions from two of the authors of Strategies for achieving healthy, sustainable, and equitable dietary transitions, recently published in Science.

The paper “connects the behaviors of consumers, producers, and the midstream actors who influence both supply and demand. It then proposes solutions based on syntheses of evidence across major intervention domains”.

Jess Fanzo and Marc Bellemare — both no stranger to the podcast — have made it easier for the rest of us to understand the complexities and difficulties involved.