Of Apricots And Almonds
One morning in late February, I found myself staring at a list of tree varieties that one could be forgiven for assuming were relegated to the sunny orchards of Greece or France. Apricot, almond, grape, cherry were among some of the thirteen varieties of fruit and nut trees I would be planting that day, yet I was not in Greece, nor or France, but rather, in the chalky downs of Swindon, standing in a fallow field under a mist of winter drizzle. “Do almonds even grow here?” I asked our resident expert, head of horticulture Ben Raskin, perhaps a little too incredulously. Ben’s good natured response was that there was only one way to find out.
Our fearless leader, Soil Association head of horticulture Ben Raskin
My task: to mix theory and practice during an agroforestry training day at our chief executive Helen Browning’s Eastbrook Farm, where I and ten other colleagues would spend the day learning just what agroforestry was all about, then putting our newfound skills to the test by helping to plant an ambitious project as part of a brand new Innovative Farmers field lab.
What is agroforestry, anyway?
A surprisingly little-known concept in the UK, agroforestry is a technique that has been practiced for many years in the rest of Europe, particularly in France; as well as the US, China and a large part of the developing world. On a general scale, the practice is straightforward, and involves planting and managing trees on farmland in return for a bounty of environmental and economic benefits. There are no hard and fast rules, but the process must involve a deliberate intermingling of trees and another form of agriculture, whether plant or animal based. Nor do trees need to be particularly exotic, although in the case of Eastbrook, fruit and nut trees were chosen as most of the produce will be used in Helen’s two local restaurants.
In addition to (hopefully) producing a fantastic bounty of local fruit and nuts, the goal of the field lab is to see how trees perform with different types of additions to soil. At Ben’s request, we spent most of the morning either dipping tree roots in a gelatinous concoction of mycorrhiza, or adding biochar to their root systems – or, for the controls, plopping them into their newfound home and covering roots up with soil. Mycorrhiza and biochar are both great for encouraging good soil bacteria, so time will tell which the trees prefer. Along with understanding what makes for the best type of soil for these trees, Helen is keen to trial different varieties of trees that will be well suited to the warmer and wetter climate that we can begin to expect the as the climate changes. Some of these varieties may be more or less successful than others, but the key is experimenting to find out what is possible.
Mycorrhiza (left) and biochar (right) trials. Which one will be best for trees?
At the same time, trees will also offer some great benefits for Eastbrook’s livestock, which will eventually find a home in this orchard, or one of the other fields to be planted up with trees in the future. It's a symbiotic relationship of sorts: while the trees are still small, hens will be introduced as they pose a negligible threat to the saplings. Hens will help keep the trees healthy by providing nutrients for the soil, and by eating pests that would otherwise find a home in soil over winter. Hens will also provide some element of weed control by scratching around under the trees, which is a great way for the birds to exhibit their natural behaviours. The small branches will provide a good environment for hens, as branches and overhead cover can make them feel more secure and safe from predators. As more trees are planted in the nearby fields, the team is hoping to introduce sheep, and once the trees are fully mature, cows will have a new home in one of the new orchards. The tree canopy will offer shade for animals in summer and shelter from wind and rain in the winter.
A tree awaiting planting.
Why isn’t every farmer doing this, I thought to myself in a way that most anyone who spent their entire working day dry and tucked up in a climate controlled building might wonder. Ben warned our crew of office dwellers that - make no mistake - there are challenges with agroforestry, which is partly why British farmers haven’t quite embraced it yet.
Unlike most typical crops, trees of any variety can take years to mature, which means it can take a similarly long time to see a return on investment. That’s not always easy - or possible - for farmers, especially for tenant farmers with shorter leases. Tree management can also be challenging. While productive hedges and cereal crops might be a relatively straightforward agroforestry combination, livestock and trees poses an altogether different sort of problem. If sheep decide that they fancy the taste of the damsons growing in their field, farmers will literally see their profits gobbled up.
At Eastbrook, one of the goals is to learn which fruit trees are most - or least - compatible with which types of animals. If sheep are indeed damson-loving, or if cobnut trees, say, offer a hardy and protective canopy for cows, other farmers can use these learnings to avoid or choose certain combinations when planning their own agroforestry projects.
Perhaps the most surprising hurdle that has stopped farmers from adopting agroforestry is the view that planting trees devalues farmland. Over the past few years a growing body of research is demonstrating that the value of trees is actually hugely underestimated both in urban and rural settings. In North America - a continent so full of trees that it’s no wonder their benefits are being taken for granted - research has found that trees on residential properties increase house values by around 7%, and that the urban forests in the Canadian city of Toronto represented the equivalent of a CAD $7 billion (£5.73bn) investment into the environment and human health and wellbeing.
Benefits for the soil, environment and climate
While it’s more difficult to quantify the environmental benefits of trees on farms, agroforestry can help combat some of the biggest agricultural challenges Britain currently faces. A shift towards agroforestry can do a great deal to improve soil quality. Trees have extensive root systems which tunnel into the ground below, helping to stabilise soil, and improving water levels, while at the same time reducing the potential for localised flooding and drought.
This translates into better soil quality, reduced soil erosion (one report showed a reduction of 65%), and reduced nitrogen leaching. Fallen autumn leaves provide an additional source of nutrients for soil, helping enhance soil biodiversity, encouraging soil formation and helping to mitigate agricultural carbon emissions by sequestering them in soil.
Wildlife also benefits from agroforestry, as trees expand the habitat available to pollinators, birds and other animals that take refuge in the branches of trees or feast on the nectar of spring and summer blossoms.
Lots of holes dug, lots of soil critters found in this fertile organic soil.
While farmers may be hesitant to make the switch to planting trees on their land, there is one bonus that comes with agroforestry: productivity. As it turns out, when two crops are grown on the same land - for example, cereal crops and fruit trees- they can yield more than if they were grown separately, in turn boosting farm productivity and profitability. Productivity is measured by Land Equivalent Ratio (LER), and studies of agroforestry systems in countries that are climatically similar to the UK’s have found that LERs range from 1.00 - 2.01 - meaning that land under agroforestry can be up to twice as productive as land under one crop only.
Readying the ground for trees, or in other words, digging holes. The trees will be planted in an semi-circular array across the field, making for a more interesting layout than straight rows.
It will be some time yet before Eastbrook’s trees begin fruiting, and longer still before the dairy herd grazes between rows of damson and loganberry trees, under the shade of a mature fruit canopy in northern Wiltshire. While my day working on the forest garden certainly doesn’t qualify me as an expert on agroforestry, it certainly turned me into a fan of this type of farming - even if it will take an age before I get to taste a British apricot.