If you're into organic gardening and haven't come across the regenerative approach, I urge you strongly to find out more! I've been banging on about helping your soil food web, increasing the microbes in your soil for a while, but this year I did a bunch of research, listened to some lectures, read a few books and feel like I've emerged with much better understanding of what's going on between our plants, the soil and the life in the soil. This regenerative approach is not just really helpful to me in the garden, it's also rather exciting! Perhaps in a geeky kind of way, I admit! But I think I'm going to have projects to work on off the back of all of this for many years to come, as I explore the implications of this new way of looking at the world. Very nice! I'll list up some sources of info for you at the bottom of the post if you want some pointers for your own research.
So drought prevention is all about allowing rain to infiltrate your soil and then providing the means for it to hang around without waterlogging the area. You've got a few steps to think about - firstly - where is rain being prevented from soaking in? Days like today are perfect for investigating this - get your raincoat on and head out there to see where water is pooling up. These areas have a problem and if you have a heavy clay soil like me, you're sure to be able to find them. If you're on a sandy soil, you can skip this step (step 1 below) and move on to step 2 - working to hold on to water.
So for a clay soil - you've found your puddling areas, and you'll notice that these are likely to be areas with moss or other problem weeds with either sharp, creeping roots or tap rooting ones, such as couch grass, dock and thistle. In these areas, there is soil compaction going on at some level in the soil profile - maybe at or near the top, but maybe deeper down. Where you have soil compaction and water logging, your plant roots cannot penetrate. They need oxygen. To be healthy, your plants need microbes and beneficial microbes cannot survive in waterlogged conditions. Disease causing ones can survive here. It's really important to sort this out.
You have two steps to improve this:
Step 1. Open up the clay using compost and grit/sharp sand.
This is the classic advice for these situations and doing this provides instant gaps between the tiny clay particles, allowing water and oxygen in. Where you have open soil, free from plants, dig these materials in. Mix them with your soil to at least a spade's depth, but ideally these areas should be double dug - dig out soil to a spade's depth and then fork over the base, mixing in compost and grit to a second spade's depth. For areas with established perennial plants, use a combination of a compost mulch, along with narrow yet deep holes filled with compost and grit/sand. To do this, use a sharpened bean pole, metal rod or similar to punch holes an inch or two wide and at least a foot deep into the soil all around your plants. Mix compost and grit/sand together in a bucket and sprinkle it into the holes.
Step 2. Seed your soil with microbes to keep it both free draining and moisture retentive in the long term.
Step one, if done using shop bought compost, can easily revert back to rubbish, waterlogged soil. Unless, that is, you set up a system for the soil to keep itself open and to keep adding more organic matter to itself each year. What I'm about to describe paradoxically helps a sandy soil in the opposite way, by also helping the soil to hold on to any water passing through. For both good drainage and moisture retention as a long term condition, you need microbes - this is where the biological, regenerative approach comes in.
Add either home made compost, a well made, aerated compost tea or a shop bought microbial soil amendment, such as an EM1 liquid feed or my current favourite from here in the UK - Microbz soil improver.
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| Watering on aerated compost tea. Note the large holes in the watering can's rose - big enough to let the microbes through. |
Microbes do three important things for the soil, in terms of drought resistance.
Firstly, they form symbiotic relationships with plants, helping them to produce ever more complex chemical structures, from simple sugars, right up to enzymes, proteins, lipids (fats) and ultimately the complex organic compounds, better known as humic acids. These humic substances are stable, organic compounds. Unlike the organic matter in shop bought compost, they cannot be digested and broken down into simpler substances, such as carbon dioxide gas. They are a stable store of carbon in the soil and will help your soil to maintain a good structure. Your soil will soak in more water, yet will be free draining enough for this water not to puddle up.
Secondly, micro organisms actively improve the structure of the soil themselves by producing a glue like substance that binds tiny soil particles into micro aggregates. Bacteria make tiny soil aggregates and fungi produce larger, yet still very small ones. All in all, your soil will become more randomly structured and so more naturally porous. Water will soak in and drain through your soil more extensively. Plant roots will be able to extend more deeply and thoroughly into the soil, enabling your plants to reach deeper stores of water during dry weather.
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| In this magnified image of some activated compost, you can clearly see the fungal hyphae as white strands. This compost has been prepared this way to make an aerated compost tea that is rich in fungi for my more woody plants. |
The third important drought busting thing that microbes do, is to use these soil aggregates to feed water to plants. Water will cling on to these teeny tiny clumps of soil in a microfilm around them, even under the driest of conditions. Experiments have shown how much water can be held this way: If a fully saturated soil is described as being 100% saturated with water, a dry, dusty soil that blows about in the wind - the type we had here in the UK in abundance last summer - is still 70% saturated!!! That's a lot of unexpected water! It's just that the water is held as a microfilm around the soil aggregates. Under normal farming conditions, or in gardens that use a lot of chemicals or have been suffering with water logged soil - ie where there are no beneficial microbes - this is a problem, as plants can't access water that is held in this way. The water is too tightly bound to the soil particles for plant roots to be able to pull it off. But microbes can get at this water and if you have lots of those in your soil, forming symbiotic relationships with your plants, they will feed this water to your plants in return for some of the sugars that your plants are producing each day.
So it's a win win situation! Drought shmought!
As I said, the way to increase microbes in your soil is by adding home made compost, an aerated compost tea or a microbial product, such as EM1 or Microbz. The best times to apply these things are the autumn and spring. This needs to be coupled up really with full plant cover - microbes and plants come together, the one feeding the other. To grow more microbes, you need to grow more plants as they live and thrive in the root systems of your plants.
Once you've set up this system, it is self perpetuating and you don't need to repeat it unless something drastic happens - like you use heavy machinery on the soil during wet weather, compacting it again. Or in a vegetable garden, that gets dug up regularly - this will damage and at least partly destroy the microbe communities in the soil, so it is worth seeding these in once a year.
As I said, I've been toying around with some of these ideas for years, but feel like I'm only now getting to grips with the wider implications of our microbial helpers. This year is the first year I've been applying these techniques broadscale in my garden. I'm looking forward to seeing the results of this and will keep you posted. If you're liking the sound of this, give it a go! And if you do, it'd be great to hear how it's working for you, so post us up something in the comments below.
For more information about regenerative practices, good starters include:
Regeneration International, who are working to increase the use of this approach globally. International news about this is posted up on their page along with their own blog articles. Inspirational reading.
Advancing Eco Agriculture are based in the US. They provide loads of free information - a blog, podcast, webinars and you tube lectures about using the regenerative approach in farming. They're doing some great work.
The book - Farm as Ecosystem - by Jerry Brunetti is a great primer.
Lastly - search for anything by Elaine Ingham on you tube. She's just great!
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