Genetic erosion: it’s complicated

From the CIAT blog:

Putting true numbers on diversity loss turns out to be a complicated and contested business, with no shortage of strong opinions. One big part of the problem is that there aren’t many good ways to count the diversity that existed before it disappeared. Researchers have done some work to assess the changes in diversity in crop varieties of Green Revolution cereals, and to some degree on the genetic diversity within those varieties. The results indicate that, although diversity on farms decreased when farmers first replaced traditional varieties with modern types, the more recent trends are not so simple to decipher.

My work here is done.

Nutrition toolkit all set to make agriculture oh so sensitive

FAO’s Toolkit on Nutrition-sensitive Agriculture and Food Systems is out. Without a huge amount of fanfare, as far as I can tell, which is a bit surprising. Anyway, good to see agrobiodiversity properly highlighted in multiple places, including as an entry point for various interventions, and as part of several indicators.

Meanwhile, that call for best practices for healthy food systems (which means nutrition-sensitive, among other things), is still open.

Nibbles: Rice in Trinidad, Sweet potatoes in Ethiopia, EU crop diversity double, Sir Peter on the ginkgo, Forages, Brazilian peanuts, Seed moisture, Phenotyping double, Svalbard deposit, CATIE data, Herbarium double, Seed #resistance, Father of the apple, Agave congress

Smaller farms, more crop diversity, more nutrients, mainly

There’s a follow-up to that Environment Reports website on farm size and nutrient production that we blogged about a couple of weeks back. The data come mainly (though not exclusively) from a blockbuster inaugural Lancet Planetary Health article.

The new website explores farm size variation among different regions of the world through some great imagery. But it also highlights one aspect of the paper that I didn’t mention in the previous post: crop diversity on farm. Here’s the relevant figure (the paper’s figure 5), mapping how many different types of crops are produced in a pixel and how evenly these different types are distributed (the Shannon diversity index, H).

Here’s what the authors have to say about diversity and nutrient production (my emphasis).

…combining the diversity measures with spatially explicit plot sizes, which are highly correlated with farm size, shows that agricultural diversity (H) decreases as plot size increases (p<0·0001; appendix). In particular, areas with small and medium farms (≤50 ha) have larger diversity than do larger scale farms. These differences also translate into differences in nutrient production (figure 6). On a global level, areas with higher diversity of food commodities (higher H) produce more micronutrients than do areas with less diversity. This effect is particularly noticeable in places such as China, sub-Saharan Africa, east Asia Pacific, and west Asia and north Africa. In contrast with North America, in Europe, although production comes mostly from medium and large farms, it is not farm size, but the diversity of production that drives nutrient production in this region.