Heretical Agronomy

[sebenikela]

There aren't a lot of hot-button controversial issues in agronomy--partly because the guys (mostly) who work on how to get 300 bushels/acre of corn in Iowa don't really hang out with the permaculture set, but also because, well, it's farming.

The exception?

Conservation Agriculture. So, background: in general, not tilling is better than tilling for maintaining soil fertility. No-till tends to reduce the soil bulk density, which means it's not packed together as tight, and that is better for roots and water infiltration and so on. No-till also tends to keep soil covered with something for the whole year, so it can't wash or blow away. I say "tends to" because while in North America that's true, crucially: it's not true everywhere. More on that ater.

Wes Jackson and others, particularly at the Land Institute (google them) have a long-term vision for agriculture where a farm field behaves like a prairie--a polyculture of mostly perennial plants that you don't have to plow or plant very often. That would be ideal, for prairie-ish biomes! Fewer weeds, fewer passes through the field with machines, fewer chemical inputs probably...

But it's long-term, because it's hard.

Meanwhile, no-till in the USA took off right around the time Roundup Ready corn (maize) and soybeans started taking off. Because the biggest problem in no-till (and organic, btw) systems is how to deal with weeds. A moldboard-type plow flips the soil over and buries all the weeds and most of them die. If you're not plowing, you have to kill weeds some other way. And with Roundup Ready crops you can spray the entire upper Mississippi valley with herbicide without worrying about it fucking up your crops.

Industrial-scale no-till is a bit like industrial-scale organic: they're probably better than so-called conventional farming, but they're not going to Fix Everything. Some organic farmers buy pelletized chicken manure and ship it across the country, apply it just like commercial urea to their field, after tilling it 4 or 5 times to get rid of as many weeds as possible. Sure, that's a better use for chicken shit than draining it into the water supply, but it's not particularly revolutionary, and not necessarily better for the land. Similarly, you can go no-till and use a shit ton of herbicides, starting with glyphosate and working your way up to older, more toxic shit as the weeds become resistant. And you'll lose less soil to erosion -- which is great! -- but it's not going to Fix Everything.

I've been talking about "no-till" up to now, because it's not actually a synonym for Conservation Agriculture. Conservation Agriculture (CA) has three principles: 1) no tillage 2) residue retention (i.e. leave the maize stalks on the field) and 3) crop rotation.

The Food and Agriculture Organization of the United Nations (FAO) (aka my supervillain origin story ) and a bunch of other big international agriculture agencies have adopted Conservation Agriculture as an ideology -- they consider it to be The Best Way To Farm, Everywhere.

It got to a point where the academic journal Field Crops Research published an article titled "Conservation agriculture and smallholder farming in Africa: The heretics’ view" (unfortunately paywalled, but let me know if you want a pdf).

CA is, in general, a pretty good set of guidelines, but it's not a universally applicable ruleset for Making Agriculture Better.

Which reminds me, what does "better" even mean, in this case? To me, "good" agricultural practices allow people to earn a living from the land they're on, while avoiding harm to the natural environment, as far as is possible. The first part of that is key (and what staranise was talking about that got me on this topic in the first place). If people can't make a living farming, it doesn't matter how environmentally beneficial their techniques are. Farming is a job, and I am very confident in saying that most farmers in most parts of the world (except parts of Europe) make well below a living wage if you count all the hours they spend working. Yes, I am including the US and Canada. That's changing, as machinery gets bigger and farms get bigger but... that's a whole other set of problems.

Anyway. So, the question then becomes, is CA the best way to ensure farmers can make a living while protecting their environment?

Except that if CA is an ideology, that's not a hypothesis, it's an axiom. It's taken as given. It's a starting point. People look at no-till in big farms in the Americas (mainly the US, Canada, Brazil, and Argentina) and go "hey, that's got some nice benefits!" ...and then assume that those benefits will exist everywhere.

And tl;dr: they don't.

In a lot of places, livestock wander around in the off season, grazing on what's left in the fields. If you want to do CA, you have to find a way to stop them from doing that. And it's not as simple as just putting up a fence (which is, actually, not simple at all). If everyone in your village lets the local cattle graze on their fields and you're like nope, I'm special, nobody's cattle are allowed on my field you're going to be In Trouble. What kind of trouble depends where you are, but in many, many places in Africa, village support networks are the only safety net anyone's got, and if you've pissed off all your neighbors, next time you need someone to loan you $5 to take your kid to the health center, you're SOL. And maybe your kid dies.

This is not hyperbole.

OK, so that's one problem. And it's a big one, because a lot of the benefits of no-till come from those residues protecting the soil. If you're just not tilling, then cattle come eat everything and your field sits essentially bare until the rains start up again, you're not getting tasty organic material into the soil, and you're not keeping your soil covered so it can blow or wash away just as well as if you'd plowed.

And then there's weeds. Herbicide is expensive, and not necessarily easy to get, and Roundup Ready crops, despite Monsanto/Bayer's best efforts, have not really penetrated the African market, as they say. So no-till means more work. More time spent weeding, and sometimes more time preparing the soil.

Wait. More time preparing the soil?

A lot of African soils (and also some in the southeast US, actually) form hard crusts when they dry. If you're not breaking up that crust with a plow, you have to do it some other way, and most of those ways are done by hand, with a hoe, bent over in fuckoff awful heat (because "just before the rainy season" tends to also be the hot season), and -- importantly -- by women. Zaï pits are the most well-known of these. They're pits dug into a field, then filled with compost, and seeds are planted into those pits. It's a fuckoff amount of work. Sure, in theory you do it once and then don't have to, but still.

And? There's not a lot of evidence that, in smallholder African farming systems, CA increases crop yields. And if you're working with African smallholder farmers, increasing crop yields is critically important. Or, rather, increasing farmer income is critically important, and that usually means increasing yields.

But because so many organizations have adopted the ideology of CA, a huge percentage of the research done on African agriculture, and a huge amount of the outreach/extension/promotion of new agricultural practices focuses on CA. People come in with the idea "how can we make CA work here?" or, if you're unlucky, "how do we make these farmers adopt CA." When really, the question scientists should start with is "how can we mak"e agriculture work better here?" with a side of "better FOR WHO?" and "what does better mean in this specific context.

Maybe CA, or some variation, will be part of answering those questions. Or maybe it's something else. For example: you can reduce soil erosion with earth bunds, which can be made with a team of oxen and a handful of people -- there's a Malian organization that charges farmers something like $20/ha to stake out contours and set up the bunds. Then you plant shrubs and trees and native grasses on them, protect them from downpours until everything's established, and you get better water infiltration, less erosion, and often better crop yields.

But you're still using a plow, so it's not CA, so it's not getting research funding. The Malian org has been doing this for 15 or 20 years, it would be fantastic for someone to go back to the folks who set up contour bunds a decade ago and see what's changed. Are they getting better yields, really? Is there less erosion? Have they maintained the bunds? But nobody's doing that. Meanwhile I get notified of half a dozen papers a week on "The Benefits of Conservation Agriculture in Country X".

And that's why ideologies are a problem: they limit creativity. They limit the kinds of options scientists and farmers can explore. And when, like any other farming practice, CA doesn't work equally well everywhere, the ideology says the question to ask isn't what might work better? but how can we make CA work here?

That causes harm. And that's why dogma has no place in agronomy.

(and why "no-till is good! plowing is bad!" is a mo rant-button, even though it's usually more true than not)

Comments

[ironed_orchid]

I'm happy you wrote this up. It's so interesting.

One of the reasons that settlers dismissed Indigenous Australians as having no agriculture is that they didn't till or plow. But now people are realising that they did practice land management in ways that Europeans did not recognize or appreciate. Bruce Pascoe's Dark Emu is the best known work on this topic.

[sebenikela]

oooh, I will have to add that to the list.

Europeans have a long and storied tradition of not realizing other people were actually managing land because they were doing it differently. (see e.g. most of the US that isn't forest isn't forest because it was periodically burned, etc) It's kind of infuriating--and makes me EVEN MORE ANNOYED that people still have not learned better...

[chickentimeschickenways]

I just read the most infuriating book about the natural history of grasslands that totally dismissed the role of Native peoples in burning maintenance. . . granted, it was published in 1982, but I wanted to reach back in time and shake the author until his teeth rattled.