To dig or not to dig?

[Tom 1]

I read something about this a couple of years back, about letting the roots remain in the soil after harvest. It didn't seem practicable on the farm so I didn't look into it any more, but I might give this a go in the garden this year:

Why cutting down on digging the garden can actually be good for soil | New Scientist

If there's a paywall this is the main part:

All gardeners need to dig sometimes, of course, such as when making holes to put plants in or rooting out weeds. Traditional advice is that we should also turn over all the soil every autumn, to aerate it, improve drainage and mix in soil improvers like manure.

For the past few years, though, I have been increasingly embracing the no-dig approach. On the allotment, I suppress weeds on bare ground over winter by covering the earth to block out light as much as possible.


I used to do this using plastic sheets weighed down with bricks. This year, I have started adopting the system of no-dig advocate Charles Dowding, a UK market gardener and writer. You put down flattened cardboard boxes and cover with some kind of mulch, such as manure or home-made compost. As the cardboard rots, worms take the organic matter down into the soil.

This approach may also be better for the soil. Most plants get help in absorbing water and nutrients from a fine network of thread-like fungi on their roots. A large component of these fungal threads is a sticky protein called glomalin, discovered in 1996. Together, the threads and released glomulin make soil clump into bigger particles.

If soil is dug over, it breaks up the particles and exposes organic material they contain to decomposition by microbes, releasing carbon dioxide. Soil with larger particles retains more moisture and is less prone to nutrients leaching away.


A recent trial in farmers’ fields shows that “no-till” boosts soil glomalin and is also likely to reduce soil erosion. On a smaller scale, Dowding says trials in his market garden show no-dig plots give slightly higher yields of fruit and vegetables – as well as being less work of course.

Sounds interesting anyway. Has anyone tried this? I suppose it depends a lot on the soil type too. The soil in my garden still needs improving, it's quite clay-y and I dig it over partly to add in more organic matter every year, in the hope it will eventually stop baking hard in the summer.

 

[Aussie Pete]

I read something about this a couple of years back, about letting the roots remain in the soil after harvest. It didn't seem practicable on the farm so I didn't look into it any more, but I might give this a go in the garden this year:

Why cutting down on digging the garden can actually be good for soil | New Scientist

If there's a paywall this is the main part:

All gardeners need to dig sometimes, of course, such as when making holes to put plants in or rooting out weeds. Traditional advice is that we should also turn over all the soil every autumn, to aerate it, improve drainage and mix in soil improvers like manure.

For the past few years, though, I have been increasingly embracing the no-dig approach. On the allotment, I suppress weeds on bare ground over winter by covering the earth to block out light as much as possible.


I used to do this using plastic sheets weighed down with bricks. This year, I have started adopting the system of no-dig advocate Charles Dowding, a UK market gardener and writer. You put down flattened cardboard boxes and cover with some kind of mulch, such as manure or home-made compost. As the cardboard rots, worms take the organic matter down into the soil.

This approach may also be better for the soil. Most plants get help in absorbing water and nutrients from a fine network of thread-like fungi on their roots. A large component of these fungal threads is a sticky protein called glomalin, discovered in 1996. Together, the threads and released glomulin make soil clump into bigger particles.

If soil is dug over, it breaks up the particles and exposes organic material they contain to decomposition by microbes, releasing carbon dioxide. Soil with larger particles retains more moisture and is less prone to nutrients leaching away.


A recent trial in farmers’ fields shows that “no-till” boosts soil glomalin and is also likely to reduce soil erosion. On a smaller scale, Dowding says trials in his market garden show no-dig plots give slightly higher yields of fruit and vegetables – as well as being less work of course.

Sounds interesting anyway. Has anyone tried this? I suppose it depends a lot on the soil type too. The soil in my garden still needs improving, it's quite clay-y and I dig it over partly to add in more organic matter every year, in the hope it will eventually stop baking hard in the summer.

It's becoming more popular in Australia, notorious for drought and floods and not all that fertile soils. It seems to work, but patience is required. It can take a few years to see results. Not digging helps worms which are most beneficial to the soil. Another technique is to run far fewer animals per square mile (farms are big here) so as not to overload the land. The industrialised approach to farming improves productivity but at a long term cost. Land clearing is contributing to CO2 emissions also. Short term profit for long term loss. Nothing new about this.