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In a 17 June 2022 interview with Field, Lab, Earth, the American Society of Agronomy podcast, Peter Thorne, a crop-livestock systems researcher at the International Livestock Research Institute (ILRI), talks about a recent study by the Africa RISING Ethiopian Highlands project that compares farmers’ traditional management of weeds in faba bean plots against improved management systems and their effect on land productivity and income.

Listen to the interview here.

Some extracts from the interview

Can you talk about Ethiopian farming at large, how that works, what it looks like, and start us off there?

I think the Ethiopian farming system is probably very different from what many of your listeners would be used to. First, people have a preconception of Ethiopia as a country that’s experienced its fair share of problems related to food production and availability. And they would be amazed to see some of the systems in the country’s highlands, which are highly productive, both in terms of crops and livestock. One of the key features of the system is this integration of crops and livestock on the same farms, often very small farms, maybe even less than a hectare but providing a whole range of crop and livestock products both for the farm household to consume themselves and for sale at local markets.

Can you talk a little bit about faba bean farming in Africa RISING?

One of the crops we have been working with quite intensively over the last 11 years is faba bean, which forms part of the system in many of the sites we’ve been working at. Faba beans, as people should know, are a legume that produces a bean that’s important for human consumption. But it also makes a lot of crop residue, which is important for the livestock components. It is one of those kinds of crops that in the smallholder farming systems in the Ethiopian highlands have a dual role. Our initial objective, I guess, was to look at the intensification of the bean production side, but the research that we’re going to talk about today highlighted some of the complexities of doing that in a way acceptable to farmers. Because, as I have said, the mixed nature of the system means that we can’t always focus on one key objective; we must consider other factors if the technologies we try to promote will be acceptable to farmers.

Can you talk about the recommendations to improve yield compared to traditional cultural practices? 

As many people will be aware, that kind of traditional agronomic approach to intensifying a crop like faba bean would apply to wheat and barley, and maize as well probably, it’s the thing. We need a better or more high-yielding variety; we need to improve our agronomic practices to ensure that yield potential is realized. We have doubled bean production. What we have found in many mixed farming systems, and the research I’m describing today is a very neat example of this, is that it doesn’t always work.

But another thing that would be very easy to miss without understanding the farmer’s objective is that farmers have a relatively unusual weeding practice. They tend to leave weeds in these crops for a long time, probably up to six to eight weeks. And they’re looking for biomass production from weeds, and they do that because they want to remove those weeds and use them to feed their livestock. And we wanted to look at alternative ways of intensifying the plot to get more grain yield. But also, we would support the other objectives that the farmer has in managing that plot, namely, to feed their livestock so they don’t die.

Can you tell me about the experiments and testing of various facts in your research?

The first experiment was exploratory; we just wanted to look at the consequences of improved management of faba beans associated with an improved variety versus the traditional crop and management practices. The implications were if we considered all those uses of the crop, we found broadly no benefit in intensifying simply with an improved variety and supposedly better management. Although, when aligned with the farmer’s objectives, it turns out that it wasn’t better management. So, we did some economic analyses based on the data we collected, and we found no improvement in the value-to-cost ratio of improving bean production in that way. And we concluded that would be a reasonable explanation for why farmers tend not to adopt intensive management of improved varieties of beans. So that was the first experiment just to set the scene.

What did you find in your second experiment, and what does it lead to?

We did it on 60 farms. It is indicative rather than prescriptive. I think the results were quite encouraging to our hypothesis that a planned system would benefit the farmer in terms of income. We had about a 20% increase in income compared to the traditional system, and we call it the conventional improved system following the traditional route. Certainly, that intercropping system did play out quite well in terms of maintaining some element of the yield gain for the beans by giving a significant amount of associated livestock feed. Another aspect we looked at was that monocrop is not necessarily best suited to growing as an integral. We tested six bean varieties in association with the well alone and with the oats in the intercrop. And we indeed found that some varieties have around a 30% difference in yield under intercropping conditions. The whole landscape changes varietals selection in terms of management practice. It is imperative to get the two in balance and get them the right principle that any agronomist will know.

What other questions are you hoping to explore as you move forward and explore these various relationships? Where are you going with this?

We had 11 years of funding from the US government. The project will be ending towards the end of this year. We do have new initiatives coming together that we hope will be able to take up some of the research conducted under Africa RISING. I am pretty optimistic about that.