Earthworms. By Yun Huang Yong via Flikr

If the holy grail of agroforestry is to optimize crop yields and productivity while maintaining the provision of ecosystem services, it turns out it might be a good idea to humour the kings and queens who live underground—nematodes, earthworms, termites and other creepy crawlies that do their work in the soil.

I attended the WCA2014 session on ‘Biodiversity and Agroforested Habitats’ yesterday morning (12 Feb 2014). The session was chaired by Edmundo Barrios, ICRAF’s scientist on Land health, and was surprisingly, or perhaps not so surprisingly, packed full.

The amount of research covered and the level of collaboration between various universities and the World Agroforestry Centre  within the six presentations was staggering.

Much of the science was beyond me, but as a lay person whose home is in one of the biggest coffee-growing areas in Ethiopia, my interest was immediately piqued by the research presented.

For example, Hairiah Kurniatun reported on shade, litter, nematodes, earthworms, termites and companion trees in coffee agroforestry in relation to climate resilience.  The researcher from University of Brawijaya in Indonesia explained some effects of cropping patterns in coffee agroforestry systems on the abundance of parasitic nematodes. Radopholus love the cocktail of coffee and banana trees but do not particularly like gliricidia (a multipurpose leguminous tree). Unfortunately, neither do earthworms.

In particular, their research showed that a mix of Coffee plus gliricidia plus avocado created lower instances of the parasitic abundance, but add mahogany and the nematode numbers almost doubled. Beautifully useful information from research.

The presentation by Mattias Jonsson, titled ‘The effects of shade, altitude and landscape composition on coffee pests in East Africa,” had one of my favourite slides, on how to decide whether shade trees are useful for control of white stemborer, coffee berry borer and lacebugs in coffee.

What was more surprising is the research by Vivian Valencia and colleagues that shows that cash crops like coffee are better for the environment, and more robust to climate variability than food crops. You see, coffee agroforestry systems are intermediate between forest and monoculture coffee in many aspects of above- and below-ground biodiversity and related functions.

For the farmer, however, the balance of positive and negative aspects of diversity needs to be understood in relation to processes such as nutrient and water uptake, slope and topsoil integrity, and harvestable yield.

Coffee agroforestry is considered a promising alternative to conventional agriculture that may conserve biodiversity while supporting local livelihoods. Another study that finds that coffee agroforestry might in fact be better for biodiversity than crop monocultures and pasturelands. Whenever appropriate, strategies and policies should trigger the conversion of coffee monocultures and pastureland into coffee agroforests, thereby sparing forests and reforesting tree-less agricultural land.

I’m sure for countries whose incomes include large amounts from these cash crops, this is very good news indeed, but what does it mean for food crops?

Edmundo Barrios in his talk argued that recommendations of what types of tree densities, arrangements and species maintain essential ecosystem functions provided by soil biota in agricultural landscape is essential. Furthermore, identifying, quantifying and mapping host spots of biological activity and ecosystem services should aim to develop local soil health monitoring systems to evaluate ecosystem service provision performance. This, said Barrios, would allow rural communities, environmental/agricultural institutions, and local governments to prepare for negotiations related to payment for ecosystem services.

I couldn’t help but wonder, in a world where money talks, whether researchers can quantify this information in dollar terms, especially for cash crops like coffee, rubber and cocoa.

Because when Wall Street’s interest is piqued, then perhaps the kings and queens of the soil will survive, and ultimately, ourselves.

By Akefetey Mamo

—

Follow the Congress on Twitter #WCA2014 for live updates!