I love putting my hands into beautiful, living soil. It’s an amazing, grounding, energetic feeling.

I enjoy other aspects of gardening: caring for plants, building compost heaps, harvesting and eating the bounty.

But getting my hands in the dirt gives me a feeling of wellbeing that goes beyond these other benefits.

I used to think it was just me.

But, I’ve found research suggesting that getting our hands dirty is actually good for our sense of wellbeing.

Dirt – dead or alive

I grew up with my hands in the dirt.

My mother, Sue Bulmer, was an archaeologist. As kids, my brothers and I spent a lot of time hanging around at digs. As soon as we were old enough, we were drafted to help out.

We usually had dirty fingernails. It was just part of being in our family. We got used to it.

You can read more about Sue here.

But, as I grew up, I realised that while my brothers seemed to enjoy the process of archaeology, I didn’t.

The soil we were carefully sifting through was often the middens, or rubbish tips, or house sites of long-ago times. But it wasn’t living soil.

In my personal, subjective experience, there’s a huge, qualitative difference between the subsoil layers that archaeologists and geologists study, and vibrant, living topsoil.

Sue Bulmer with family, 1967

Sue Bulmer with her excavation team, December 1967. “Family to dig in New Guinea”, said the New Zealand Herald headline. From left: David (5), Kenneth (3) and me (6).

The life of soil

When she wasn’t running an archaeological excavation, my mother liked growing vegetables. She always had a compost heap in the backyard.

I remember Sue arguing about this with her New Guinea highlander colleague, Ian Saem Majnep.

Saem thought Sue’s compost heaps were nasty and unsanitary. The highly skilled, traditional horticulture methods on the steep mountain sides of Saem’s home region, the Kaironk Valley in the Eastern Highlands, didn’t involve compost heaps.

I think Saem had a point. Healthy compost heaps need care, skill and attention. Sue had a very short attention span for anything that wasn’t 20,000 years old.

Saem, who passed away in 2007, was an international pioneer in the field of indigenous science. He co-authored books with my father, Ralph Bulmer. He also worked on many archaeological excavations with my mother, Sue Bulmer.

Ian Saem Majnep

Ian Saem Majnep in archaeologist mode in 1970, at an excavation in the Port Moresby area organised by my mother, Sue Bulmer.

Two kinds of soil science

There are two contrasting and (I think) incompatible strains of soil science.

There’s the “conventional” industrial soil science model, pre-eminent in the 20th century, and still running in the 21st century. In this model, soil is seen as a non-living medium, a collection of minerals, to which humans add fertilisers and other nutrients in order to grow produce. Like a planetary hydroponic growing system.

The soil food web

The other kind of soil science is the soil food web model. Soil is understood as a dynamic living medium in which micro-organisms and fungi collaborate and co-exist with other elements of the soil.

I’m sure you can tell which side I’m on.

The soil food web model underpins both organic growing practices and the regenerative agriculture movement.

And also, my mother’s compost heaps.

One of the well known soil food web researchers is American microbiologist Dr Elaine Ingham.

Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web, by Jeff Lowenfels and Wayne Lewis (Timber Press, 2010) is a great introduction to the soil food web.

If you’re in New Zealand, here are some local soil food web practitioners and teachers.

The food-soil connection

The “soil is dead” mindset accepts that soil will gradually become depleted in nutrients, through years of farming or horticulture. This means that more fertilisers and other inputs are needed.

Specialist kumara grower Joe Gok (acknowledged as an expert in his field) stated in a radio interview that the land he’d been growing crops on was getting less fertile over the years. He took this for granted.

Food grown in soil that’s depleted in nutrients will also be deficient in nutrients, no matter how many fertilisers are added.

Our tastebuds won’t necessarily notice. But it results in widespread malnutrition on a subclinical level, and chronic health problems.

There are other implications. Depleted soil is actually dead. The micro-organisms and other soil biology get stressed and die, after repeated application of inorganic fertilizers and pesticide, herbicide and fungicide sprays.

Also, depleted soil is less resilient with drought or extra-heavy rain. It doesn’t hold water like healthy soil does. It’s prone to erosion and run-off into waterways. The topsoil layer gets thinner.

Blueberry grower Paul de Groot, of Monavale Blueberries, commented to me that there was a big difference between the topsoil depth on his organic farm and on the neighbouring land, which was being farmed using conventional industrial fertilisers.

Soil regeneration

The news isn’t all bad. With care and skill, soil can be regenerated. Even dead soil, that’s been drenched with toxic chemicals.

And it doesn’t have to take generations.

One of the growers who has been practicing and researching this for many years is New Zealander Jim O’Gorman, of Kakanui.

Jim, who is also known as the “Dirt Doctor”, has a 20-year sequence of soil tests demonstrating that soil fertility can be improved while growing produce on land continually over many years.

I’m writing a post about Jim’s research – watch this space.

Alive and dynamic

I’ve been hugely inspired by soil food web researchers.

By natural inclination I’m a worm farmer, composter and maker of naturally fermented foods and garden fertilisers.

I studied biology at high school, and we investigated earthworms for two years in a row. I drew diagrams of earthworms and even dissected the poor creatures (yuck!).

But we never learned about their place in the big picture of soil biology. The soil food web was not in the high school biology curriculum in the 1970s.

I didn’t find out about that until I started worm farming.

For me, compost is literally a site of alchemical transformation, where food waste turns into nutritious living soil. It’s a place where I can connect to the continual processes of life and death. Compost is both living and dying at the same time.

Dirt isn’t dead – it’s alive and dynamic. The soil is a site of constant cycles of life and death, and everything in between.

Children and dirt

Many small children love getting dirty. Whether it’s playing in a mud puddle, or running their diggers through soil, or helping in the garden.

Early childhood education specialists say this is an important part of child learning and development. It’s tactile, embodied, connected learning. It’s very different from sitting quietly on a mat, listening to a teacher, watching a screen, or reading a book. Young children need more than these quiet, non-active modes of learning.

There’s an early childhood play area that was called “mucky play” when I was at Playcentre. This could be dirt, but it could include fingerpaint, or water play, or bubbles, or playing in a sandpit, or paper shreds, or mud kitchens… mucky play is incredibly open-ended.

Educator Pennie Brownlee, author of “Magic Places: the Adults’ Guide to Young Children’s Creative Artwork” and “Dance With Me In The Heart”, thinks the term “mucky play” devalues the importance and appreciation of this kind of especially creative play. It’s also called “messy play”, but even that is a bit negative.

My friend Anna Fairley, who is a kindergarden teacher, says another term for this is “sensory play”.

Playing in the dirt is a particularly important aspect of messy play/ sensory play. But most kids get very little of this.

As parents we are worried about keeping our children clean and tidy. We get judged for having grubby kids. And, we have some well-founded concerns about the safety of playing in the dirt.

kids in the sandpit

Above: my sons Tom (at right, in blue) and Albert (in red) in the sandpit at Balmoral Playcentre.

Dangerous dirt

I don’t want to scare you off getting your hands in the dirt. But sadly, there are some good reasons for being discerning. The typical New Zealand suburban backyard quite probably has toxic chemicals in the soil.

Snail bait was the wake-up call for me.

One sunny afternoon I planted a bed of lettuce seedlings while my sons Tom (3) and Albert (6 months) were playing on the lawn. I added a row of blue snail bait at the edge, to make sure the lettuces got a chance to grow.

Straight away, Tom and Albert came over and started playing in the dirt at the edge of the garden. In the snail bait.

I’m ashamed to admit that I lost the plot. I rushed my sons inside, washed them off, and settled them in front of the TV.

And I stopped using snail bait, even the kind that’s allegedly less toxic. If it kills snails, it’s not good for toddlers.

I’m very glad this didn’t put my sons off gardening. I’m proud to say that in his late 20s, Tom is now running an organic gardening business. He doesn’t use snail bait.

Tom Bannister gardener

Above: My son Tom Bannister the gardener. I’m so happy I didn’t put him off gardening permanently!

Soil testing

Even if you don’t use snail bait or Roundup, there may be persistent agricultural chemicals in your garden, dating back to horticultural use of the land.

There may also be lead contamination from old house paint. Our family cat Benjy got lead poisoning from sitting in a warm patch of dirt that included house paint sanding. He recovered and led a long and active life.

Cat poo is yet another yucky thing you’ll find in backyard soil. Thanks, Benjy.

You can get your garden soil tested for some of the main toxic chemicals. In Hamilton, Hill Laboratories do soil testing. Look online to find a company that works in your area.

If your garden soil doesn’t get an all-clear, you can put in raised garden beds to grow food, and for the kids to play in.

A hundred years ago, people died from tetanus, an organism that lives in soil, before the anti-tetanus vaccine was widely available.

Even today, people can get seriously sick and sometimes die from legionnaire’s disease, which is caused by an organism that may be present in soil, especially commercial compost.

Clean or healthy immune systems

Avoiding contact with dirt isn’t the answer. As I said, I hope I haven’t put you off!

There’s substantial research that suggests children need to be exposed to dirt in order to develop healthy immune systems.

Our modern western culture is obsessed with hygiene and cleanliness. But in general, many people don’t get exposed to enough dirt in our daily lives.

There are direct correlations between the microbiology in living, healthy soil and our intestinal flora. Having healthy gut flora is essential to optimum health.

In Finland, some daycare centres provide forest floor areas so the children can experience dirt.

Soil stewardship

As humans, do we think of the earth as an endless resource that we can profit from and use up, personally and individually, without giving in return?

Or do we take care of the earth for future generations of humans – which means all humans, not just our own grandchildren.

And what can we do towards this on a practical level?

It’s not just about money, it’s about quality of life. It’s also about food quality and nutrient levels.

And stewardship of the world.

For me, caring for the soil is my personal practice of environmental activism.

More reading

Here’s an article I wrote about organics: Organics – a line in the soil?

And a post about plant intelligence: Smart plants

And My life with green salad