Knowing Our Soil All Over Again
Zhou Miao Fei
Translated by Yan En

Most people live in the cities nowadays. Many have never touched the soil or waded across a stream in their whole lives. We used to have a closer relationship with soil in the past. In the modern times, our feet are cut off from soil by different types of materials, and we educate our kids to stay away from soil, thinking that it is dirty with germs.

But our survival depends on soil. Animals, including humans, need to rely on plants for survival. And plants need sunlight, air, water and soil. Soil dictates the quality of plant growth. If the soil has sufficient nutrients, we will obtain rich nutrients. If the soil is polluted, the plants will be polluted, and the humans who eat the plants will also be polluted.

At present, we often talk about the horror of pesticides. Consuming organic foods has become a trend. Learning to grow veggies and fruits has also become a talking point. The priority of organic farming/gardening is to first grow healthy soil. All organic gardeners know that if one takes good care of the soil, the plants will grow well. Healthy soil benefits animals and humans. Therefore treat your soil well. So how do we take care of the soil? First we have to learn about soil and then cultivate good and healthy soil.

Ideal Soil
An ideal soil is a world of rich organisms and balanced ecology. It is rich with humus, in dark brown color, light, crumbly, and easy to work with. It can retain moisture and yet drain away excess liquid. It is also aerating. It is brimming with active micro-fauna, micro-flora and earthworms. The ideal world of soil is active, lively and ever changing.

Structure of Soil
Soil is a mixture of rock elements, water, air and organic matter. On average it is 45% rock elements, 25% air, 25% water and 5% organic matter. The more organic matter it contains, the more fertile the soil is. The content of organic matter in our modern day soil is probably not even 1%. Thus adding organic matter regularly is the most essential job in caring for the soil. A good veggie bed should have 30cm layer of top soil, which is rich in organic matter and microorganisms. The ratio of the rock elements is moderate with sufficient aeration.

Soil Quality
This refers to the combination of coarse and fine rock elements in the soil, from coarse sand to silt to clay. The ideal ratio is 40% sand, 40% silt, and 20% clay. Rock elements absorb moisture which contains soluble nutrients. The gap among the elements is for aeration. If the gap is too big like between coarse sand granules, then the soil can’t retain moisture and nutrients. If the gap is too small like in clay, then the root can’t extend and breathe.

Rub the soil with your fingers and you’ll roughly know the quality: the coarse granules that feel like beach sand are sand, the smooth one is clay. Mix soil with water and roll it into a longish shape: soil with high content of clay can be rolled without scattering; soil with high content of sand can’t be rolled into a longish shape as it will scatter. The ratio of soil elements in general falls between these two. Different spots in the garden may have different quality. Do the soil test a few more times and you’ll find out the different ratio.

A simple soil test that you can do at home: prepare a tall container, fill it with 7 portions of water and add 3 portions of soil (dig apart the top soil, take the soil from the top to the lower layer. Check soil from different spots separately). Cover the container and shake the container until the soil is mixed evenly. Keep it aside for some time. The granules in the water will separate due to different sizes. The fine granules settle in the bottom, moving up are sand, silt, clay, and then water. The surface may even have half-decomposed twigs and leaves. Looking at the proportion of the different layers, you will know your soil ratio. It is very difficult to change soil quality, but we can add organic matter to improve the soil structure.

Soil Structure
The way soil elements bind together is called soil structure. Brush aside the debris on the surface of soil. Retrieve a handful of wet soil, you will see how soil elements bind together: a well-structured soil has a moderate ratio of sand, silt and clay, mixed with organic matter and they form light and fluffy lumps.

Air in the Soil
Healthy soil needs air. Plant roots breathe within the soil. The microorganisms inside the soil also need to breathe. Certain special bacteria in the soil can transform nitrogen in the air into a form that can be utilized by the plants. So there should be moderate gap among soil elements to allow for aeration.

Soil Moisture
Good quality soil can retain the moisture needed for plant growth, as well as soluble nutrients, while draining away excess liquid. Most plants like soil with good drainage.

The composition of soil may be different in different spots. The effect of drainage is different too. You can observe the drainage effect at home after a heavy downpour. If your soil has more sand, the liquid will drain too fast, and the plants will often wither and appear droopy. If small puddles are formed after a downpour, or the ground remains muddy for several days, then it means that drainage is poor. The microorganisms inside the soil cannot survive; roots soaked in the water will turn pale and rot; leaves will fall and the plants will lack vitality.

Organic Matter
The remains of fauna and flora that are breaking down in the soil contain important plant nutrients. The stabilized organic matter after the decomposition is humus. The dark brown color of good quality soil comes from the humus. They are like a sponge that can retain moisture and nutrients for the plant roots to absorb. They can also bind the rock elements and turn the soil soft, crumbly and fertile. A humid climate and rich microorganisms in the soil can break down organic matter, thus accumulating more humus. A dry and hot climate with little plants and too much tillage will decrease the humus in the soil. The climate in Taiwan is warm and humid with rich varieties of plants. But most of the soil lack organic matter and microorganisms, so there is almost no humus.

Living Organisms in the Soil
There are bacteria, fungus, actinomyctes, ants, beetles, centipedes, spiders, etc. in the soil. The more diverse group of organisms there are in the soil, the healthier the soil is. Earthworms are the most important indicator. They burrow in the soil along with various tiny organisms, letting moisture and air reach the plant roots. Excretions from earthworms are the easiest nutrients to be absorbed by the plants. The microorganisms in the soil can break down organic matter, transforming them into a type that the plants can absorb. Soil is the home to these tiny living beings. They go through the cycle of birth, growth, seeking food, breeding, and death. They rely on soil to obtain food and shelter. When they die, they become the nutrients in the soil.

Soil Nutrients
The nutrients in the soil are continuously lost through rain, over watering, natural decomposition, or being absorbed by plants. Plants are like us, they need their daily meals. To feed your plants, first give your soil sufficient nutrients. Once the soil has organic matter, only then will the living organisms breed and gradually reach a balanced state. It takes at least 6 months to a year to establish the ecological equilibrium. If you have just started growing plants organically, and you think that the soil is lacking nutrients, you may first use organic fertilizer while cultivating the habit of supplementing your soil with organic matter. Organic farming certification unit and environmental groups have information on qualified manufacturers. You can buy mixed compost, animal manure compost and so on. The municipal environmental protection authority, Taiwan Environmental Protection Union and so on also sells compost made of kitchen scraps. Mix the compost in the soil a few weeks before you start planting. During the planting period, add the nutrients once every few weeks.

Soil pH
The nutrients in the soil are absorbed by the plants when they are mostly neutral in pH value. For example, when acidic, nitrogen and sulphur can’t be absorbed; when alkaline, iron and magnesium can’t be absorbed. Plants have their pH preference. Most vegetables like neutral to slightly acidic soil. Organic soil is between neutral and slightly acidic, thus does not need adjustment. Simply sprinkle rock dust once a year. Rock dust can neutralize acidic soil and helps bind rock elements.

How to Increase Soil Fertility and Productivity?

1. Mulch with Organic Matter
All organic gardeners have a good habit – any green organic waste that they come across is returned back to the land. Green wastes come from the kitchen (fruit peels, veggie scraps, tea leaves, material from flower arrangement, etc.), garden, balcony (plant cuttings, old plants, etc.), lanes, roadsides (fallen leaves, etc.). As long as they are plants, they all contain nutrients from the earth, and they should be returned back to the earth. We can continuously and directly put the green stuff on the ground as mulch to cover the soil.

Empty fields, under huge trees, safety island, etc. – places that do not need a great deal of nutrients can be mulched with tree barks, coconut husks, sawdust. These are organic matters that break down slowly. They can protect the soil from wind, sun, and rain, prevent evaporation, enrich microorganisms in the soil, release nutrients after decomposing, and improve soil structure.

2. Use Home-made Organic Fertilizer
We can also turn green wastes into compost through fermentation and then apply it in the soil. There is a huge amount of kitchen scraps created by each family daily. These are good ingredients for making compost. When you start to make compost, you can buy zymophyte, or bring back a few handfuls of fertile soil from the forest or mountain streams. You can also get some compost from your friends who are organic gardeners. Sprinkle some culture at each layer of the compost. This will speed up the process. If you don’t have any existing culture, with patience, population of zymophyte will gradually form in the compost.

Fresh ingredients especially fruit peels and so on will attract fruit flies and other insects during the initial stage of breaking down and fermentation. They are not harmful to humans. They will disappear at the later stage of composting. To prevent fruit flies and insects, use more soil to cover the compost.

3. Making a Simple Compost
Prepare a big flower pot and some soil to make compost on your home balcony. Put a layer of soil, a layer of green wastes, a layer of soil, a layer of green wastes and so on. Sprinkle some water to maintain moisture. All the fine laborers in the soil (the rich microorganisms) will naturally break down the green wastes into organic fertilizer. Green wastes from our home are mostly high in nitrogen and moisture. They break down fast and with the high temperature in the summer, they will be done in just two weeks. When the breaking down process starts, the liquid will be drained out. If the pot you use has no drainage holes, you need to turn the soil for aeration. When there is too much moisture, anaerobic bacteria will grow and foul smell will appear when the organic matter is being broken down. Simply add some soil to absorb the moisture and turn the soil to aerate it. The foul smell will disappear a few days later.

If you have a lot of ingredients, use a big container with drainage holes. Layer the ingredients as mentioned above. Keep for a few months. Sprinkle some water once in a while. Turning the soil is not necessary. But if you turn the soil it will speed up the process.

4. Making High Temperature Compost

  • Collect all the organic materials: grass clippings, fallen leaves, kitchen scraps, straw, etc. Finer pieces will break down faster. You can use a leaves grinder or a mower to chop up the materials. Wooden blocks, twigs, newspapers should be chopped up too. Avoid using oil, meat, bones. These will attract cats, rats, dogs and so on, and will slow down the decomposition. Also avoid manure of pet animals and humans, and materials that have been treated with pesticides or herbicides. Find a spot near your veggie farm, pile up the materials on the spot directly or in a container.
  • Make a 1-meter fence with wire mesh or untreated wood. This looks neat and can deter cats and dogs. Or buy a ready made compost bin or a turning compost bin.

 

  • You need to collect materials that can be piled up to 1 cubic meter. If the pile is too small, it won’t be able to reach 60-70°C. Use a pitch fork to pile up the materials layer by layer: equal amount of carbon material (brown color, woody material such as sawdust, straw, newspapers, etc.) and equal amount of nitrogen material (green color, moist grass clippings, kitchen scraps, weeds, cow manure or horse manure, etc.). Too much carbon material will not generate the high temperature needed, and decomposition will be slow; too much nitrogen material will give off foul smell. When you’re doing the layering, add a few handfuls of soil in between to supplement microorganisms. You may also supplement minerals that are lacking. If there is a sick plant, place it in the middle. Only the heat in the middle can kill the germs.
  • Maintain moisture of the pile, but not wet. For high temperature compost, the bacteria need moisture and oxygen to grow. If the materials are too dry during the layering, sprinkle some water at each layer. Cover the top layer with water-proof canvas to maintain moisture. Too wet or too dry will affect the speed of decomposition.
  • The bacteria that break down the organic matter need water and oxygen in order to function. The simplest way is to use a pitch fork to turn the pile. Remove the outer layer and pile it on a new spot next to the original pile. Now the outer layer becomes the inner pile. Continue to move the layer so that the inner layer of the original pile becomes the outer layer of the new pile. Loosen up the materials. When it is too dry, sprinkle some water. Aeration speeds up the activity of mircoorganisms and raises the compost temperature. Check the temperature. When it’s too low, turn the pile. Do not let temperature exceed 70°C. Too high a temperature will kill the bacteria. If the pile heats up too much, let it sit for a few days or sprinkle some water to lower the temperature. A high temperature compost will be ready in two to six weeks. By this time the temperature would have stabilized, and you won’t be able to recognize the original materials. The pile will become dark brown, soft and fluffy. It smells like moist forest soil.

5. How to Use Compost

  • Raise seedlings: Use a 1cm-holed sieve to sieve out the bigger chunks. Use the compost by itself or mixed with earthworm compost or other potting mix.
  • Veggie garden: Every year spread compost on garden soil surface 2.5cm-5cm. For soil lacking in nutrients, you may first spread some organic fertilizer and then compost. You may loosen the soil and mix in the compost evenly or spread it on the surface as mulch.
  • Compost tea: Compost can be made into liquid fertilizer and used on saplings or fully grown plants. It can be used throughout the year. Put 1 liter of compost in a cloth bag and hang the bag in 4.5 liter of water for several days. Dilute when used on saplings. Use as it is for fully grown plants.
  • Source of bacteria: Compost contains rich bacteria culture for fermentation. It can speed up the decomposition of organic matter and balance the ecology of microorganisms in the soil. After some time when the soil has been spread with compost, you may directly put green wastes on the soil surface. Covered with straw for aesthetic view. The microorganisms and bacteria in the soil will quickly break down the stuff.

 

6. Growing Groundcovers
Landscaping, safety island, roadside empty ground, etc. – can be planted with perennial, short ground-covering plants to protect the soil. They can beautify the view, reduce dust and retain moisture in the soil.

Sometimes the soil is temporarily left unused. We can grow flowers as living mulch while beautifying the surrounding at the same time. What’s even better is that these flowers will absorb the nutrients in the soil to prevent nutrient loss. When you want to switch to another type of plant, just slash the flower plants, chop them up and use them as mulch material or put them in the compost bin.

7. Growing Green Manure
When the soil needs a lot of nutrients during the planting period, you can grow green manure plants such as grains to improve the soil. Two to three months before planting the actual crop, sow the seeds of the green manure crop. Just before they start to flower, slash them and turn them in the soil. After they break down and decompose, they will increase the organic matter and nutrients in the soil. During the fallow period, use the green manure as living mulch to prevent soil erosion.

The best green manure and living mulch plants are legumes. They collaborate with the beneficial bacteria in the soil to turn nitrogen in the air into a form that can be utilized by the plants to increase soil fertility. Sunflowers are gorgeous, fast-growing, and a good green manure. Grow them for two months. When they flower, slash and turn them in the soil. Three weeks later you may grow your crops. Besides increasing soil fertility and organic matter, the hollow stalks of sunflowers increase aeration in the soil.

Once we know the characteristics of soil and the methods to care for soil, we will then understand that only organic farming can cultivate dynamic soil. I keep a small garden at the various places that I have stayed. Initially the garden soil is poor with serious pest problem. I buy fully fermented mixed animal manures as fertilizer (cow, goat, horse, poultry, etc.). Then I start to grow various plants. Meanwhile I collect kitchen scraps and plant clippings to make compost, and I continuously spread the compost in the garden. After a year, the garden would gradually become self-sustainable. Just a garden of several square meters, it is filled with papayas, guavas, passion fruits, Madeira vine, banana shrub, and all sorts of flowering and ornamental plants. On the ground is African Touch-me-not that self-propagates and flowers throughout the year. All my visitors are amazed by the vitality of my garden.

Once a balanced ecology of soil is established, I don’t have to buy fertilizers anymore. I put the kitchen scraps directly beneath the mulch material. They break down and vanish within a few days. The soil becomes more and more fertile; various beneficial insects happily take up residency, e.g. earthworms, bees, mantis, eumeces, etc. – they keep the harmful pests to minimal. I have only one secrete: feed the soil with organic matter!

Soil is our root. I still remember when I followed my father to the river in the outskirts several decades ago. The soil by the river was dark and fertile. When we dug apart the soil, many earthworms in the soil frantically scurried away. Nowadays, the use of chemical fertilizers and pesticides is taken for granted. Everyone can buy them, everyone can use them. It seems like everyone only knows how to use chemical synthetics. But our soil is becoming more and more barren. It becomes acidic and losses the nutrients. Even the weeds do not grow. It is worrying: In the near future, will our beautiful island gradually undergo desertification? Will there be any more life left in the soil? Will the spring become silent?

Original article is published in May&Aug 2006 issue of Lapis Lazuli Light magazine (Taiwan)