A no-till approach to cultivation

Introduction

We have a older house on 0.5 acres in New Bothwell, which seems vast when compared with the 0.01acres we had in UK. The vegetable plot had been worked for many years, but was overgrown, the soil was compacted with a poor structure and had probably been maintained mostly through the use of chemicals rather than organic materials as there was no sign of any composting in the yard. Daunted by the large L-shaped plot on the west and north of our property, we decided to focus our efforts on about half of it to start with. We decided to try a no till approach for a number of reasons:

1)    We don’t have a tiller, have never used one, and are too much of a scrooge to rent one;

2)    We don’t like digging – its too much hard work (although the dog would love to help);

3)    We have been reading about mycorrhizae and the important role they play in nutrient uptake by plants, but how they are destroyed by tilling;

4)    We wanted a system that would conserve water in dry summers;

5)    Having shipped goods from England we had a supply of cardboard boxes (organic matter) to use;

 Sheet mulching

With an overgrown plot, sheet mulching suited our needs. It is basically the idea of composting in place. That is, the compostable material is added to the vegetable beds to rot down in place, and the soil organisms remain undisturbed. Sheet mulching is a very forgiving process – so long as you have a weed barrier, and top it with a good layer (ideally 12 inches (30cm)) moist decomposable organic matter it will make soil. The ultimate sheet mulch is set out below (from Hemenway 2009. Gaia’s Garden. A guide to home-scale permaculture).

 

 

    

 

Materials list for the perfect sheet mulch for 200 square feet:

1. 2-3ft stack of non-glossy newspaper or 300 square feet of box cardboard (alternative materials include cloth, old clothes or wool carpet of natural fibres);
2. Soil amendments – lime, rock phosphate, bonemeal etc.
3. 4-8 cubic yards bulk organic matter (6-10 2-string bales) – straw, spoiled hay, yard waste, leaves, wood shavings, grass clippings or mixtures of the above so that the C:N ratio is between 30:1 and 100:1.
4. 0.5 cubic yards compost
5. 1 cubic yard manure
6. 1 cubic yard straw, leaves wood shavings

 Keep the materials dry until you use them.

 Mulching

The day before mulching, water the site well unless it is moist from rain. Slash down any vegetation, but don’t pull weeds up. Leave the vegetation in place, but remove any stumps or big woody pieces. When mulching day comes

1. Add soil amendments
2. If the soil is clay and compacted spike holes over the site
3. Add thin layer of high nitrogen material eg grass clippings – 1 inch thick. This layer is not essential but gets the worms working
4. Lay newspapers and/or cardboard to create a continuous light-blocking layer to smother existing plants. Overlap sheets by about 6 inches. Newspaper should be laid at least 1/8inch thick.
5. Wet sheets thoroughly as you go so this layer is soaked, but avoid walking on it
6. Lay a thin layer of nitrogen rich manure or fresh green clippings
7. Next lay 8-12 inches of bulk mulch – loose straw, hay. Break bales into flakes 1-2 inches thick and lay down about 3 layers, with nitrogen rich material in between.
8. Spray water on as you go to keep this layer damp
9. Add an inch or two of compost or compost plus soil – this will act as a seed bed if you are planning to seed within a few weeks.
10. Final layer is 2 inches of weed and seed free organic matter such as straw, fine bark or wood shavings.

 Planting

Push the top layer aside to reach the soil layer. Seeds and seedlings can be started before the mulch breaks down, by making pockets and trenches about 3 inches deep and filling them with soil or compost. A rule of thumb is that they should be planted in a volume of soil about 3 times the root mass. Deep rooted plants can be planted by making an ‘x’ slit in the cardboard layer replacing the mulch and planting above the slit. Trees can either be planted before mulching or by making a slit in the cardboard layer, peeling back this layer and digging a hole to plant with the root crown about 1 inch above the old soil level before replacing the mulch.

Fresh sheet mulch is not as productive as one that is 6 months old, and the second season seems to be prime and maintained for several years. Renewal is easy – just add more mulch.

 So, did we do all of this?

No – we haven’t got to know all the ready sources of the materials we needed in our area. We had cardboard, grass clippings, and we brought in a mix of compost, soil and sand (to help drainage and soil texture). We didn’t use straw.

 The results of our efforts in year 1, planting straight into the mulched beds are below: 

 

What would we do differently?

 Find as much free material as we can

1. Use straw or spoiled hay
2. Consider edging the beds and developing raised beds
3. Put down bark chippings on pathways
4. We mixed our plantings up into ‘guilds’ such as the 3-sisters – corn, beans and squash, but plan to get more complex to get more benefits from ‘guilds’
5. Plant more trees and work towards a ‘forest garden’
6. Cultivate beds in our front yard using sheet mulch and centred around trees.