I’ve been asked for more detail on the agroforestry project we’re running. If you aren’t interested in agroforestry/permaculture the next few minutes could be quite boring. If you are interested, you may find the next few minutes lacking in detail; as with so many things, I have a wide but shallow knowledge of the subject.
If I say it’s also known as alley cropping it may help you envisage what I’m trying to describe. The video here gives a good explanation, though it’s American so the crops differ.
The idea is that although we give up some land to the trees they will have financial benefits when we crop the apples and other less quantifiable benefits, including shelter, micro-climate, biodiversity and organic matter.
The organic matter will come from the leaves in autumn and the smaller prunings, which will be left to rot.
Biodiversity will result from the trees giving homes to a range of birds and insects. Hopefully this will result in some form of biological pest control, though I’m not sure that it won’t also offer a have to pests. I must look that up.
The final benefits are shelter and better micro-climate. That’s what we are trying to measure. Common sense tells you that the trees will act as wind breaks and that it should be warmer in the alleys (if the wind is coming from the side). As with a lot of common sense, nobody has any figures to back it up. There are figures on the internet about the wind breaking power of trees, and their capacity to form warm micro-climates but it seems there isn’t much evidence to back it up.
At the moment we measure the wind speed and temperature at various points in the alleys every month. The Woodland Trust has provided the equipment and training for this and we send them the results each time we measure. We also measure the trees once a year, though it’s not very difficult at the moment with them being shorter than I am. The test will come in a year or two when we see if we’ve been able to remember how to use the inclinometers.
This measuring will be done for the next 20 or 25 years (I forget exactly, as I won’t be here by then) and will, we hope, be very useful in calculating the benefits of this sort of planting.