Ways to Feed Your Soil

Soil is the bedrock of any permaculture garden. The quality of your soil will affect the plants you can grow, how well they thrive and the harvest you can yield. The soil is also key in the health or otherwise of natural wilderness. Too often in the modern world, the intricacies and important role soil plays in the health of the planet and the productivity of an environment is overlooked. Modern agricultural practices and removal of vegetation and trees has caused many areas to suffer a complete degradation in the quality of their soil, meaning that either very little grows there, or any crop requires a lot of artificial fertilizers and pesticides. These in turn further deplete the soil of its natural goodness until eventually it becomes barren.

Permaculture seeks to preserve the unique characteristics of soils in different ecosystems. It also tries to repair damaged soil and protect it from further degradation. The primary means of doing this is to increase the amount of organic matter in the soil. Organic matter puts essential nutrients back in the soil, which in turn promotes healthy plant growth and an increase in the bacteria and microorganisms that help to transform those nutrients into forms that are available to plants. On a permaculture site there are several ways that you can ‘feed’ your soil more organic matter.

Compost
Compost is an excellent way of utilizing so-called waste material for a useful purpose in your permaculture garden. By composting food scraps from your kitchen, prunings from your trees and scrubs, grass cuttings, dead animals and, basically, anything that was once alive, you can create a rich, fertile compost. There are many different recipes for compost but as a general ule you want about two-thirds brown matter – the prunings, animal droppings and so on – and one-third green-matter, such as food scraps, leaf litter and grass. Water your compost well and make sure it is aerated, and soon bacteria and microorganisms will colonise your compost pile and turn it into useable material for adding to your soil. Compost is often a valuable addition to plantings in zone 1 of your site.

Animal Manure
Animals have an important relationship to the health of the soil. This stems from the tiny microorganism, beetles and bugs that break up the soil to give space for plant roots to grow, water to percolate and air to circulate to the larger livestock animals who can provide manure. Animal manure is key to getting nitrogen back into the soil. Omnivorous animals for which meat can form a part of their diet, such as pig and chicken, have more nitrogen in their droppings than grazers like cows and horses, but all will benefit the soil if placed around plants. Just be aware that sometimes, animal manure may contain undigested seeds, which may come from plants that you don’t want to encourage on your permaculture site.

Organic Mulch
Organic mulches such as straw, grass clippings, newspaper and woollen clothing break down more slowly than other forms of organic matter provision, but they offer other benefits that make them incredibly useful. So, as they slowly break down, releasing nutrients back into the soil, they provide insulation from extremes of temperature, cooling the soil in the summer and keeping it warm in the winter. They also ensure that moisture is retained in the soil and that it is protected from erosion by rain and wind. And, of course, one of the main functions of mulching is to act as a weed barrier or to cover existing weeds and break them down into organic matter.

Legumes
Legumes are essential for a healthy soil. They are the family of plants that have the best nitrogen-fixing ability. Certain bacteria that live in their roots convert nitrogen into a soluble form of the element that plant roots can take up and use to grow. Species such as peas, beans and acacias are legumes and by providing available nitrogen they help stimulate plant growth and bacterial activity that, in turn, helps develop the organic matter in the topsoil.

Cover Crops
Permaculturists know that cover crops serve a lot of functions. They help to minimize water evaporation from the soil, they provide shade and, importantly, they add organic matter. This is because cover crops, such as potatoes and pumpkin, have deep roots that open up the soil, allowing water and nutrients to penetrate into it and stimulating microorganism activity. These roots also help maintain the integrity of the soil, and the leaves of cover crops rot in place and return their nutrients to the topsoil.

Green Manure
Green manure crops are similar to cover crops, but rather than remaining in the soil and naturally decaying in winter and revitalizing in spring, they are deliberately cut and then left on the surface or forked into the soil to add organic matter. Species such as rye grass, barley and lucerne are commonly used as green manure crops, and are slashed back several times when growing as they regrow very quickly. Just make sure you slash before the crop flowers and seeds to retain control over the crop.

Biofertilizers
Biofertilizers have been used among ancient faming cultures for centuries, but it is only recently that they have become better known among modern gardeners. Biofertilizers offer an alternative to artificial fertilizers that are potentially damaging to the soil, crops and the environment (polluting rivers and so on). They are microorganisms that are cultivated on natural material in laboratories and then added to the soil in large numbers. They help increase the biodiversity of microorganisms in a soil, they reduce pests, and, of course, increase fertility. They can also be used to heal soil that has been depleted by chemical fertilizers or exhausted by monoculture practises.

However you choose to do it, adding more organic matter to your soil is almost always a good thing. The animals in the soil will become more productive, your plants will flourish and the productivity of your site will increase. What’s not to like?

Five Elements of Healthy Soil Composition

Good, healthy soil is essential for any permaculture garden. As the growing medium for your plants, it is the foundation on which everything else is based. A healthy soil’s main task, besides giving the plants something to physically be in, is to break down organic matter into forms that can be utilized by plants and other organisms. There are five elements of a healthy soil that interact to enable this function to be performed.

Moisture
The moisture level in a healthy soil is important for the health of the plants growing in it. The water that is in the soil, either from rainwater or irrigation, provides the vehicle through which soluble nutrients become available to plant roots. While you don’t want soil to become waterlogged, as a general rule, it is preferable to slow the rate that water leaves the soil. Some moisture in a soil will transform from liquid to gas and evaporate into the air. This depends on temperature and atmospheric pressure, and occurs particularly in places with little rain. Adding ground cover plants and preventing direct sun or strong winds attacking the soil can help retain moisture in the soil. To slow the rate of water percolation through the soil – meaning that it takes nutrients away from plant roots before the plants have had a chance to access them – add more organic matter such as compost to the soil.

Mineral Composition
Of significant importance in the retention of moisture in the soil, is the mineral composition. This refers to the proportions of different types of particles in the soil. A soil with a larger proportion of clay minerals, which are very fine, drain more slowly and hold water well, but form a hard, impenetrable surface in dry conditions. Soil that has a greater proportion of larger particles, such as sand, drains more quickly − which can be good for areas of high rainfall. For most areas, a mixture of the two is preferable, allowing for a medium level of drainage, which means nutrients are still available to plants but the soil does not become waterlogged. However, the ideal type of soil for your permaculture site will depend on the specific weather conditions that act upon it.

Gases
The three primary gases present in a healthy soil are oxygen, nitrogen and carbon dioxide. Plants use carbon dioxide to help with photosynthesis, a byproduct of which is oxygen, which is then used by animals in the soil. Nitrogen is an essential gas for plants to build proteins, perform photosynthesis and form DNA. When the levels of these gases are in equilibrium, the soil is healthy and plants and microorganisms thrive. To ensure a healthy level of gases in the soil, there needs to be an effective exchange of gases between the soil and the atmosphere. This exchange ensures that there is an adequate supply of oxygen in the soil to allow plants and microorganisms to thrive. Without the exchange potentially damaging levels of other gases, such as sulphur dioxide, can build up. The effectiveness of the exchange of gases is linked to the structure and composition of the soil, and takes place via two main processes.

Mass flow refers to the exchange of gases that takes place after rainfall or irrigation. As the water percolates through the soil, gases are displaced and enter the air. Conversely, when water from the soil evaporates, atmospheric air enters the soil. Diffusion, the more common form of gas exchange, involves the exchange of gases between the soil and atmosphere depending on the respective pressures of the gases. So, if the pressure of, say, carbon dioxide in the atmosphere is greater than that in the soil, it moves into the soil to create an equilibrium, and vice versa.

Organic Matter
Organic matter is the magic ingredient in a healthy soil. It gives the soil nutrients, can help the mineral composition (making clay soil moreopen, and helping sandy soils preserve water and nutrients), will add nitrogen to the soil, and affect the retention of moisture. The organic material also provides food for the microorganisms. Thus, you really can’t have enough organic matter in your soil. There are many ways to increase the amount of organic material on your plot. Composting turns food scraps, garden prunings and anything else that was once living into nutrient-rich humus that can be added to soil around plants. Cutting back crops such as barley and wheat and leaving the cut plants on the ground will allow them to break down directly into the soil, while mulching offers the duel benefit of a slow release of organic matter from the mulch itself (which can be anything from branches and leaf litter to woolen carpet underlay or old jeans) and the breakdown of weeds beneath the mulch as they are deprived of sunlight, and then rot into the soil.

Microorganisms
When there is a good balance between the gases and water levels in the soil, and there is sufficient organic matter, microorganisms will be abundant in a soil. This makes it healthy, as these organisms – bacteria, fungi and insects – have many positive effects on the soil to keep it in good condition. They break down nutrients in the soil and so make them available to plants. They break up the soil, providing space not only for plant roots but also air and water to penetrate the soil. And when they die they become part of the organic matter, returning their nutrients to the soil in the cycle of life. The more microorganisms – and the greater range of species – the better, as the ecosystem will become self-regulating, preventing any build up of pest populations.

All five of these elements are interacting all the time. Initially, it can seem daunting to think that you need to balance all of them correctly to ensure your plants survive and thrive. However, remember that nature will naturally try to find a way to achieve that balance, and by observing and replicating nature, it shouldn’t be too had to create ad maintain a healthy soil.