Growing your own food is like printing your own money

Most urban plots of land today have hard, dry, lifeless soil or at most a sort of lawn of grass or a mix of plants, grasses, trees, growing on hard soil. So the first thing to do is to ensure no rainwater is allowed to leave the land 

This article is based on a pandemic backdrop series of writings, awareness programs and discussions promoted by the Daily FT Harmony page on the link between healing the soil and healing of humans. The Harmony page will also be shortly announcing the practice based actions we will be introducing along with several stakeholders, to encourage general awareness on enriching the soil, conservation of rainwater and conservation of indigenous seed varieties as well as promoting the foresting concept for ‘free food cultivation’ in public spaces.

The below article explains some simple ideas to maximise the conservation of rainwater to enable soil healing which in turn will facilitate the cultivation of forest gardens in homes and public spaces to combat climate change. 

• But money requires a bank and soil is the “bank” which grows your food And water is the medicine that heals the soil

By Ranjit Seneviratne  

Why ‘heal the soil’?  Because chemical agriculture has literally murdered the soil micro-biome – the very heart of soil. Everywhere you look, soil is hard and lifeless while rain-water just runs off into drains and rivers. But look at a forest – it is the soil that makes it grow so luxuriantly, without any irrigation, fertilising or weeding. so “heal the soil forest gardening” is based on what happens in a forest.

Most urban plots of land today have hard, dry, lifeless soil or at most a sort of lawn of grass or a mix of plants, grasses, trees, growing on hard soil. So the first thing to do is to ensure no rainwater is allowed to leave the land – in line with what King Parakramabahu decreed; “Not one drop of water should flow to the sea without serving man”  because water inside the soil is “soil medicine” – the “healer”, it is what connects everything together, the plants, trees, bacteria, viruses, funghi and mushrooms, nematodes, worms, insects – everything that lives in soil. So it would be wise to harvest rain water by making sure it is not wasted in drains or flowing onto roads, where it finally ends in rivers or the sea.

Harvesting rain water by flooding is an ancient practice done in Sri Lanka by our kings, landscaping the land to collect water into our famous “tanks”.  This was done to prevent soil erosion due to flowing water, which removes precious top soil and bird and insect droppings as well as twigs and leaves hurtling down from the trees. Rainwater falling amply onto soil allowed more water to seep deeper into the soil and these two factors increased the depth and richness of the biomass of soil micro-biota, worms and insects in turn, nourished plants and trees and birds, animals and us.

Harvesting rain water from the roof

The method used in our dry zones, is to collect roof rain water into large tanks. This can be done in Colombo or anywhere, by leading the roof gutter down pipes into normal plastic water storage tanks. These tanks should be placed on a brick or other structure so as to be high enough above ground, so that water can flow down a hose pipe to water the garden, without the need of a pump.

Since the gutter down pipes are bigger than the standard overflow pipe at the top of the tanks, it would be necessary to cut a hole and fit a larger pipe as the overflow pipe. To prevent mosquito breeding, fit a cover with a mesh (brass or stainless steel). As dirt from the roof will collect in the tanks, it is necessay to drain the tanks periodically, to flush out dirt from the bottom of the tank.

If there are trees or if leaves collecting in the gutters, then it would be necessary to cover the gutters with half-inch plastic-coated wire mesh. It would be wise also to make a “leaf trap” for the tank. This is easily done by cutting a hole in the water tank cover and putting in a one-gallon plastic bucket so that about half of the bucket sticks out above the tank cover. Cut a hole in the bucket, a little bigger than the diameter of the gutter down pipe and put in a brass or stainless steel mosquito mesh into the bottom of the bucket.  The leaves will collect in the bucket and can be periodically cleaned out. The mesh will also keep out mosquitoes. 

To prevent mosquito breeding in gutters where water collects, drill 1mm holes to drain this water. To prevent splashing by the falling water, make it flow down a stainless steel or brass wire or nylon fishing line (thangus) kept in place by tying a brass screw at each end, one to keep it place in the gutter and the other buried in the soil or in a flower pot.

Harvesting rain water that falls in the garden

Do this by making sure water does not run immediately into drains, by having the drain “lip” about one or two inches above ground level, allowing rain water to flood the garden for about one or two inches. 

In order to keep the drive-way dry and usable, it would need to be about 11/2 to 21/2 inches above the level of the garden. Similarly, paths around the house or back yard would need flat stones or concrete paving blocks placed so that they are 11/2 or 21/2 inches above ground level.

For houses without drains around the house, landscape the garden around the house, with a positive slope for about three or four feet or more from the foundation to the level of the garden. The level of the garden should preferably be four to six inches below the level of the bottom of the house or foundation, to keep out water from the foundation area. As in the case above, make sure there is a one to two-inch flooding of the property by raising a barrier to the water flow going out of the garden.  

Two-inch flooding – will it affect the foundation of a house?  

According to people in house construction, houses are designed to be at least one foot above ground level to allow a maximum flood of 12 inches. So a two-inch flood would not have any adverse effects.

Excessive flooding

If the property is prone to excessive flooding, then it would be necessary to make a “soakage pit” by digging a pit say 3ftx3ft or 4ftx4ft by 6ftx8ft deep, filling the bottom with large stones and then progressively smaller stones and finally covering it with sand. This makes a kind of “short cut” for water to quickly reach the water table. However, in houses built on marshy land that has been filled with soil, “soakage pits” may not work as the water table could be rather high.

Rain water harvesting on land with a slope

This is done by terracing the land at suitable intervals along parts that are at the same level or “contour” and putting in place “erosion barriers” – short bunds or walls (of cement or normal bricks) that are say two inches higher than the land. Water will collect and flood up to two inches the area behind the bund and the overflow would go to the next level and so on until finally the water could drain into a pond or a “soakage pit”. These barriers should be gracefully curved or “S” shaped along the contour to look more natural and graceful, as curves also add strength to the barrier. 

Importance of having a pond as a water feature

Having a pond at the lowest level would be a natural choice, but the reasons for having ponds are many, from providng a water source for birds and insects (very necessary for butterflies) to using it for home cooling, by having a small pump make a “water fall” down a rock feature built against a house wall that gets a lot of sun. Evaporating water from the rock feature cools the rocks and therefore the walls – a sort of natural air-conditioning. 

Having Mosquito larvae eating guppy fish would make it anti-dengue mosquito and dragon flies eat flying insects and their grubs feed on mosquito larvae too. Frogs and toads also feed on flying insects (I have three ponds, two for wall cooling).

To start soil healing, use food waste as soil conditioner (increases earth worms, etc.)

Food waste is always available. Most people put it into dust-bins, but some use it to make compost in compost bins.  A cleverer way is to make kitchen and table food waste into a “worm soup” by using a blender with a little water. Then dig a small hole in the soil about eight to 10 inches deep, pour it in and cover with soil. No mess, no flies, rats, etc. and in even three days everything except bone pieces and eggshells would be gone. 

This soil healing process could be done any where any time, even by people who do not want to garden, as it increases availability of friendly bacteria, etc. around the home with beneficial effects (including natural vaccination) for all the family, thereby improving their micro-biome, which will increase their immunity against diseases.

Why you need leaves and twigs from large trees to start a forest garden

In order to have a “forest garden” you need to start with leaves and twigs from big trees, similar to what is found in a forest. The reason for this is that most soils have been stripped of minerals by repeated conventional farming (much taken out and very little put back in) and about 40 years of chemical agriculture. Hence the need to use deeprooted tree leaves and twigs to heal the soil, as the soil deep underground should still have good mineral content

How to make a speeded-up composter for leaf composting, instead of a compost bin or pit

Leaves, twigs on the forest floor compost rapidly because there is plenty of oxygen. But compost bins and pits need turning over and take weeks and even months to compost, because of a lack of oxygen or air.  A simple solution – make a small circular composter three or four feet in diameter, using small mesh plastic, with a larger mesh bottom to allow worms to enter the composter and a cover to keep out rain from wetting it too much and draining the soil-like structure made by the worms, etc. 

For a bigger, rectangular compost bin with provision for tapping “wormywash”, have a slightly sloping concrete base that would drip “wormywash” into a plastic gutter with a half inch hole at one end to collect “wormywash” into a bucket buried in the soil. The sides of the bin is made with small mesh plastic with poles (or pipes) at the four corners and a roof over the bin and collector to keep out excess water, but with sufficient space between bin sides and roof for good access.  Leaves and twigs are placed in the bin and regularly watered with a light spray to keep it moist.

The “starter” of worms and micro-biota is made by burying peeled bananas about half inch in the soil. Depending on worm density in the soil, there would be plenty of worms feeding around the bananas the following morning. Carefully pick up the worms and bananas with a generous amount of soil and place it deep inside the mass of leaves and twigs. The bin should be regularly watered to keep it moist and should never be allowed to dry out

Note: “Wormy wash” is rather strong and should be diluted if used to fertilise potted plants.

Collecting necessary inputs for healing the soil – ‘bio char’ charcoal 

In “heal the soil” gardening/farming, it would be wise to make “bio char” charcoal – made by burning thicker branches in a metal drum about two feet in diameter and about two feet high (such drums are available along Central Road. Pettah). Wait until all the wood is burning well, then cover the top of the drum to minimise air/oxygen, so that the fire would go out, but the wood would continue to burn and finally become charcoal. 

Research has shown that “bio char” provides very large surface areas for microbes, which helps enrich soil micro-biota. The charcoal should be broken up into smaller pieces (not powdered) and mixed into the mulch or soil.  Large logs too big for burning should be buried about two feet deep underground, as they would be a long term resource for the soil biota. Even better is “activated charcoal” from coconut shells.

Adding a SAP (Super Absorbent Polysaccharide)

SAPs are typically powders that absorb a lot of water and may be a wise addition to your soil (by making half-inch holes, and using a half-inch plastic pipe to get the powder deep into the soil in as many places as possiblle) as a way of increasing moisture in the soil against prolonged droughts caused by climate change. Avoid chemical types which are expensive.

Fortunately a Young Girl from South Africa made a SAP from orange peel. She won first prize in a Google Science Fair Competition. Follow what she did in this video – https://youtu.be/hwUtDvcHPpQ  or hopefully an enterprising person would start making this locally following some other unique recipe.

An easily available substitute is coconut husk or “kohubuth” as a coarse powder.

Initial preparation with suitable cover crops

While organic animal and compost fertiliser, wood chips and leaf material, bio char, etc. are being collected in sufficient quantities and stored or piled up in a corner of the garden, a cover crop of grasses, weeds and nitrogen-fixing plants (e.g. beans) should be grown, because research has shown that all plants including weeds, actually regenerate and fertilise the soil, because over 25% of the carbon they remove from the atmosphere through photosynthesis, is put into the soil. For old lawns and over-grown gardens, growing beans all over may help nitrogenise the soil.

Setting up the “healing the soil” process 

When everything is ready, the land is first covered with paper (preferably white and brown paper) to block out sunlight and kill the existing weeds, grasses, cover crops, etc. which will become compost. Cover the paper with a layer of a mix of animal dung, leaf waste, bio char and rock dust (from a hardware shop) and dolomite as mineral input. 

Next mix in a four-inch thick layer of wood chip mulch so that the bits of twigs and leaves ae mixed into the compost, which allows air to be trapped – very important for soil organisms, who like all forms of life, require air, water and food. So it is best to start the process during the rainy season, but if not, it would be necessary to water the mulch covered land every evening, to allow the micro-biota in the soil to start the process of soil healing.

(The writer is an engineer who promotes soil healing and the forest garden concept.)