By Victoria Burton
The GROW Observatory went to Oxford in September for the Permaculture National Convergence, there were talks, walks, workshops, and practicals with different individuals and organisations, including Extinction Rebellion, foraging, engaging children in permaculture, making biochar, bees and pollination, and lots more.
Myself and Naomi van der Velden attended the National Convergence to communicate the exciting findings, tools and resources created through the GROW Observatory and run practical workshops. We began on Saturday with a talk introducing the GROW Observatory, including viewing a video.
I then spoke about the Changing Climate Mission and how communities all over Europe have been using soil sensors to ground-truth soil moisture data from satellites, provide data for mapping soil moisture and finding out more about how their growing practices affect soil moisture patterns. Naomi presented the Living Soil Mission, including results of the Great GROW Experiment and introduced the GROW App as a source of reliable information on permaculture practices and planting and harvesting dates tailored to your location — crowd sourced and validated by growers.
After lunch, Naomi and I met up with some Permaculture Association soil sensor users to find out about why they are using sensors and what they have found out so far. Our attendees had found it really interesting to see how varied soil moisture was across their site and there were lots of ideas for using sensors in experiments, such as comparing dig and no-dig areas.
Later in the afternoon it was time for a hands-on GROW workshop on soil texture and pH. We had several buckets of mystery soil and got our attendees measuring texture using the hand-texturing method. You can try this method in your own growing space using our guide. We had a sneaky inclusion of potting compost, this contains no mineral particles at all (and called an organic soil) so soil texture does not apply.
On Sunday there were more workshops, starting with myself running an earthworm survey. September is not a great month for earthworm surveys as after the warm, dry summer weather, they tend to go deep underground. Thankfully I found a moist shady area in the shadow of a building which had plenty of earthworms!
I spoke a little about the different types of earthworms and their importance for soil health before starting on the practical activity. An earthworm survey is simple to do. You dig a hole, remove the soil and then sort through it picking out any earthworms into a container. A solution of mustard powder in water can be poured into the hole to bring up any earthworms deeper in the soil — it’s a light irritant but doesn’t do them or the soil harm. I provided everyone with an Earthworm Watch chart to help them identify their earthworms into three types: soil-feeding, surface-feeding and deep-living earthworms.
The numbers of different earthworms can tell you something about your site. Surface-feeding and deep-living earthworms feed mainly on dead organic material and are sensitive to disturbance, they can reach high numbers where no-dig methods and lots of compost or manure is used. The pale-coloured soil-feeding earthworms ingest the soil itself, they can survive in less rich soils and are tolerant of disturbance by ploughs, digging or rotavating. To observe how earthworms change the physical structure of the soil by burrowing you could build an earthworm hotel.
Later in the day Naomi ran a session on using tools and technology to get a better understanding of your growing site. Armed with smartphones, soil sensors, compasses and clinometers we learned how to measure and map out our location in preparation for a permaculture design. We demonstrated the soil sensors by placing three in different places, one in a grassy area, one under a tree, and one in woodland. Everyone had an opportunity to see the live readings from the sensors and compare the difference in light, temperature and moisture levels in the three environments. We also had more people sign up to the Changing Climate Mission and take soil sensors home with them. Find out more about practices which can grow soil and ecosystems, such as no-dig in our Regenerative Food Growing practices infosheets or download the GROW Observatory app.