Our test to get the mycorrizal fungi back in the soil has now been going for 6 months. We were very interested to see what the impact of winter would be on our soil microbiome.

As a reminder of what we did we’ll summarize our previous post

After discovering that the mycorrizal fungi hadn’t returned to an agroforestry plot even after 4 years, we went out to discover how to bring them back. We found 4 methods and decided to test them all. 1 burying potatoes in first soil 2 using fungus rich compost 3 adding forest soil 4 planting seedlings with soil from the forest.

In our first test using 30cm of soil after a month we found:

Control plot with 2 fungi
1 potato plot with 2 fungi
2 compost plot with 7 fungi
3 forest soil plot with 7 fungi
4 forest seedling plot with 12 fungi

Now we did the same test but with 20cm of soil and 6 months later at the end of March:

Control plot with 6 fungi
1 potato plot with 6 fungi
2 compost plot with 6 fungi
3 forest soil plot with 17 fungi
4 forest seedling plot with 16 fungi

There was a difference in depth of the sample which can explain a large part of the increase of the fungi in the control and potato plots. However we were also going into winter and this test was at the start of spring so that might also have an impact on fungi activity or sprouting.

What we can conclude is that the fungi we had in the compost have not stayed over winter. The fungi in the forest soil are more robust for the agroforestry plot we did the test on. Also we didn’t see a difference between the two forest soil inoculation methods. This means we could save time in the future if we don’t want saplings from the forest.

Around plot 4 with the forest seedlings we took another 4 samples
1 25cm from the seedling in the treeline
2 60cm from the seedling in the treeline
3 25cm from the seedling into the grass
4 100cm from the seedling into the grass

The most amazing result we had was that the number of fungi in these 4 was between 14 and 16 so not very different from the ‘original’ locations. This is very promising as it means these rows are already expanding and bringing more soil life to the grasslands as well.

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