Trees & Tree Farming

Most people have a picture of traditional farming as animals grazing in flat pastures, or as golden wheat waving in the breeze. But we have not always used cereal husbandry as our primary source of food.

In the Middle Ages, farmers of Western Europe used to herd livestock into the deciduous forests where they could feed themselves on seeds, nuts and berries from the trees. Larger trees such as Beech (Fagus sp), Oak (Quercus sp), Walnut (Juglans regia), and Sweet Chestnut (Castanea sativa) would often tolerate the growth of smaller food-bearing trees beneath their branches (for instance Hazel, Corylus sp, Cobnuts and Filberts etc.) making direct feeding easier for the animals (mostly pigs).

This combination of several layers of vegetation represents the most productive use of available sunlight and soil in a given land-area.

Manure from the animals would be dropped where it was most needed, automatically ensuring that the woodland floor remained rich and fertile. Any surplus food would be gathered by the farmer and stored as winter feed. Nutritionally, the feed from this system is of a surprisingly high quality (see table 1) and compares very favourably with the cereal feeds currently used on our farms. Shelled walnuts, for example, contain up to 16 per cent protein, in addition to fat, calcium, iron and vitamins B1, Riboflavin and Niacin.

However, since the Middle Ages, the use of cereals as a main crop superceded tree-farming. As a result, farming became strictly governed by seasons, with a premium put on planning one year ahead. Farmers could now settle in one area but were committed to obeying the rigid cycle of a handful of annual crops. Modern agriculture now has these grasses trained to follow a simple uniform geometry, tailor-made for conveyor-belt machinery on our flat farms.

In the rain forests of New Guinea, nomadic treefarmers still employ a system of cultivation which we call 'swiddening' (derived from an old Norse word meaning `clearing'). Firstly, a clearing is made in the forest and the cuttings are either burned or composted to release their nutrients. A garden is planted with a varied arrangement of vegetables to ensure that variations in terrain are complemented by different plant heights etc.

The crops are harvested sporadically, according to day-to-day needs, in order to maintain uninterrupted continuity of growth throughout the seasons. New tree shoots are carefully protected as they begin to grow amongst the vegetables, since they allow the garden to mature untended without undergoing a grassy stage. Because of their deep roots, the young trees (referred to by the New Guineans as 'Duk Mi' -or `Mother of Gardens') absorb the nutrients which run away through the vegetable roots and which would otherwise be lost. On bare hills, by the introduction of trees, nutrient run-off can be reduced by a factor of up to 100.

The New Guineans seldom keep their gardens for more than one year, moving to a new location while the forest reclaims the last one. Pigs are kept as a high protein investment for times of sickness or stress, and represent their only method of food storage. In this way, even though less than a tenth of the forest is `used' at any one time, it will support 200 people per square mile in complete ecological stability.

It is well-known that the major deserts were produced by cereal farming on a large scale and consequent erosion of the soil. Some experimental, work has been undertaken to re-introduce mixed economy tree-farming in the tropics. Certain drought-resistant trees such as Algaroba (Prosopis juliflora) and Carob (Ceratonia siliqua) have been used to upgrade poor soils and to provide food for livestock and people.

Good varieties of Algaroba can produce up to 50 tonnes per hectare annually (see table 2) in addition to their longrterm payoff in the form of timber. The Algaroba pods are nutritionally superior to maize and can easily be ground into meal for both human beings and for animals. Livestock may be supported in this way on indifferent soil at densities of 5 to 12 large animals per hectare (cattle etc.) or up to 62 small animals per hectare (sheep etc.).

Such abundance is not confined to tropical regions; one harvest from a single mature Portuguese Oak has been shown to equal the output from a whole acre of Maize, 1200 litres of Acorns.

TABLE 1.2 &3

Since only eight per cent of the world's land surface is suitable for efficient cereal farming, it is difficult to see why Governments do not take a long-term view and reforest the land for food. The only unsuitable regions would be the ice-caps:- even Iceland has passed a bill in parliament for extensive tree-planting to reduce both land-erosion and the price of food.

In an intensive forest system, many by-products could be profitably adapted for industries parallel with agriculture. Research carried out by NW Pirie has shown that most leaves contain at least as much protein as most vegetables in common use (see table 4).

It is a fairly simple process to remove the fibrous matter and to produce a high-grade curd for supplementing human or animal diet. This would provide an even greater food output per hectare than suggested by conventional figures. Subsidiary `crops' such as timber, honey, milk, chemicals, wool and wild game are all benefits which would result naturally from a well-run tree-farm economy.

Obviously, initial investment costs would be high for such a long-term farming cycle, but there are one or two short cuts possible. The Juglans sieboldiana species of Walnut is a quick-growing, high quality tree, and Carob trees can bear crops within two to three years from planting. Cereals and vegetables should grow adequately where trees are not fully established, provided the leaf-cover is thin.

With intensive horticultural research and development, it is feasible that Britain could become self-sufficient in food, whilst reducing its dependence on fertilizers, pesticides and fuel.

TABLE 4