No dig/no till
No dig gardening or no-till agriculture is based on observing deep and productive temperate forest and grassland soils, where a top layer of nutrient-rich material is added without disturbing the existing topsoil.
There are several benefits:
- Fewer weeds as seeds remain buried and don’t germinate
- Existing soil structure remains intact, including pores and channels in the soil which improve aeration and water movement
- Soils retain moisture and are less prone to erosion (by up to 90%)
- Animal life is less disturbed, and soil biological diversity is maintained
- It doesn’t involve lots of time and energy in digging
- There is some evidence that yields are higher compared to tilling
This approach can be challenging if your soils suffer from compaction, especially if they are of a clay texture, or if you have aggressive weedy species. Weeds like bramble (Rubus fruticosus) or dock (Rumex species) may need to be dug out initially, then weeding is a ‘little and often’ job.
No-dig is often used in combination with leaving crop residues, mulching and composting.
This approach recognises that sometimes digging or tilling is necessary, but aims to minimise it. Conservation tillage is an example of this. Instead of turning over all the soil completely, some of the crop residue (e.g. the stalks) is left on the surface to help shade the soil, retain moisture, and provide shelter and food for wildlife. This approach can also reduce wind and water erosion and improve soil quality compared to conventional practices.
Read more here - links to a literature review and includes sources of evidence.
This text is based on an academic literature review by Chris Warburton Brown, Permaculture Association (Britain) as part of our collaborative GROW Observatory project.
The GROW Observatory has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 690199.