Living Soil, Healthy Food

Conserving living soil is not new; sustainable agriculture depended on knowledge of soil for centuries. Simple guidelines for retaining and replenishing the life of soil are provided by John Stollmeyer and Erle Rahaman-Noronha who founded Caribbean Permaculture Consultants. Pat Ganase reports.

 

 

Healthy soil is the essential foundation on which to grow healthy foods. The practice of permaculture helps us to build soil on degraded lands so that farming takes place in a continuous loop in which soil is replenished naturally. It is possible to produce food without destroying other ecosystems. Permaculture processes aim to rehabilitate soil, trap water and grow food on small-scale intensive systems which are labour efficient and which use biological resources instead of fossil fuels. Permaculture is based on design: perfect for home gardens in which you consider topography, how water flows and what is already growing there. Remember, in a forest, there is no waste, everything is used and re-used in a continuous cycle.

 

THE THREE SISTERS

The tradition in the Caribbean is to plant corn, pumpkin and a legume such as pigeon peas, bodi or string beans together. The corn is a heavy feeder; the legume supplies nitrogen to the soil and the pumpkin keeps down weeds. These associated plants - in different combinations - will maintain and can increase the fertility of soils.

 

 

Leaf litter should be used in mulching and composting, to enhance soil.

Bois canot is a pioneer that roots deep, attracts many organisms and provides leaf litter.

COMPOSITION OF SOIL

Soil is composed of minerals, organic matter, water and air. The part of soil that remains largely concealed but is the powerhouse of its health are the organisms - small animals, worms, insects, larvae, fungi and microbes. A teaspoon of soil can contain over five billion living organisms all connecting to keep the soil healthy.

 

BUILDING SOIL

Fallen leaves are far too valuable to throw away. In composting, a pile of organic matter decomposes into fertilizer. Because leaves are rich in materials, they make particularly good raw material for enriching garden soil.

 

Composting of any organic material is preferable to burning or sending to the landfill. When you compost, you are producing nutrient-rich material that can make your soil structure better.

 

Here are a few tips to turn the dry season’s leaf fall into great compost:

 

Pick a spot, set aside a convenient two-foot by two foot area of your yard. Ensure it will stay moist; not dry out in the dry season or get water logged in the rainy season.

 

Collect leaves. Any dry leaves and grass cuttings will do. Some of the leaves can be used as mulch on plant beds to conserve moisture, cool the soil and keep down weeds. Manure can also be used to supply nitrogen.

 

Layer it on. Leaves are low in nitrogen and should be mixed with nitrogen-rich material. Kitchen waste - vegetable scraps, eggshells, coffee grounds - is a good source. Place the nitrogen-containing material between several layers of leaves.

 

Add and aerate. Throw in kitchen scraps every day if possible. Make sure the material stays moist. If it dries out, add water but not too much to make it soggy. Every three weeks, turn the pile with a garden fork. The pile should not smell bad; if it does, turn it.

 

Three to six months is average to extract usable compost; the finished compost should be dark, finely textured and slightly sweet-smelling.

 

MULCH

Mulching suppresses weeds and reduces erosion during the rainy season, keeps soil cooler and moister in hot dry weather. As soon as the soil temperature goes above 38C many of the micro-organisms begin to die. Worms prefer mulched soil and their burrowing helps aerate soil which lets water penetrate. All these factors promote strong root growth.

 

Soft nitrogen rich mulches like banana leaves, heliconias and lawn clippings encourage beneficial soil bacteria. Hard woody carbon-rich mulches like tree bark or prunings encourage beneficial fungi. Both bacteria and fungi are essential, helping to release minerals that feed plants. By varying the type of mulch used, soil micro-organism diversity improves. Mulching with compost made from both woody and soft materials encourages healthy soil that is easier to work and which does not erode easily.

 

(Artificial fertilizers accelerate microbial activity and rapidly use up the organic content of soil; reducing soil and plant health.)

Many root crops like cassava, yam and tannia are almost maintenance free.

 

Dasheen has been made into ice cream. Its leaves are used in callaloo

 

PIONEERS AND SOILS

On cleared or burned sites, “pioneer” plants - which are able to thrive in harsh, low fertility conditions - begin the cycling of nutrients by mining and accumulating available nutrients. As more nutrients enter the biological system and vegetative cover is established, conditions for other species become favourable. Pioneers such as nitrogen-fixing trees (NFT) have symbiotic relations with bacteria that convert nitrogen in the airspaces to soluble nitrates and tend to benefit other forms of life by boosting fertility and moderating harsh conditions.

 

NFTs are often deep rooted which allows them to access nutrients in subsoil layers. Their constant leaf drop nourishes soil life which in turn can support more plant life. The extensive root system stabilizes soil while constantly growing, dying and decaying, adding organic matter to the soil and creating channels for aeration. There are many species of NFTs that can provide useful products and functions, food, wind protection, shade, animal fodder, fuel wood, living fences and timber as well as providing nitrogen to the system.

 

In the tropics, most of the available nutrients (over 75%) are not in the soil but in the organic matter. In subtropical and tropical forests, nutrients are constantly cycling through the ecosystem. NFTs establish readily, grow rapidly and re-grow easily from pruning. They are perfectly suited to jump-start organic matter production, creating an abundant source of nutrient-rich mulch for other plants. Many fast growing NFTs can be cut back regularly from year to year for mulch production. As part of a productive system, they can serve many functions: immortelles provide micro-climate for shade-loving trees like coffee and cocoa. Examples of NFTs are pigeon peas, moringa and tamarind. If you see a cleared hillside, the pioneers might be bois canot.

 

 

EAT WELL WHAT GROWS WELL

Have you ever noticed the trees in yards of older residential neighbourhoods: lime tree, mango, breadfruit, guava or West Indian cherry, providing food and fruit for birds and people.

 

We need to conserve the many varieties of fruit and food that have been grown locally over time and adapted to the climates within Trinidad and Tobago. Many of our children are growing up without knowing local sources of essential foods, surrounded by imported flour, oil and meat. It is important to recognize this and surround our homes and our communities with food producing plants that are easy to maintain.

 

Local root crops (ground provisions) are hardy plants that anyone can grow in the backyard, and which can be multiplied easily; different types will grow in conditions from swamp to dry earth, from shade to full sun. Plantings in the backyard require little attention; no pesticides; and may be ready for harvest within a rainy season. In swampy earth, grow dasheen; in damp soil, tannia, eddoes; in dry poor soil, cassava; in the forest, yams.

 

The more you grow, the more you will learn about your relationship with soil.

 

We need to conserve – by planting – tropical fruits in our gardens for the children; five fingers and abiu.