MEDICAL TESTAMENT

Grey River Argus, 6 September 1939, Page 5

MEDICAL TESTAMENT

(By Major-General Sir Robert McCarrison, M.D., F.R.S.). It is not .difficult to understand that the use of artificials in feeding the crop direct side-tracks a portion of Nature’s essential round; artificial stimulus applied year after year, and at the same times, must inevitably breed evils, the full extent of whicn are as yet but dimly seen. The relation between quality and yield, for example, does not lend itself to scientific formulae. The time may come when yield will depend entirely upon quality, but quality can never under any circumstances, depend upon yie d. Factory-made manure is the weak link in the chain of agricultural economics.

The Doctor and the Links: It seems obvious to us that the new knowledge of nutrition compels our profession to return to the Hippocratic view—in so far as it has abandoned it —that a physician is a naturalist and must take cognisance of the other links of the cycle of nature as well as of man, his patient. For only so can he understand his patient. Without pretension to agricultural knowledge we can appreciate the bearing of Sir Albert Howard’s discovery of the principles of the treatment of animal and vegetable refuse on ouiwork.

Disposal of Town Wastcsr Whether his discovery can be harnessed to the problems of public health, to the sanitary disposal of municipal and village waste has, we understand, been investigated. That side of the matter does not closely concern us; but we understand that the disposal of town wastes on a large scale at Nairobi on these principles has succeeded. A short description of this important experiment is given as follows, taken’ from a lecture by Sir Albert Howard to the London School of Hygiene and Tropical Medicine, 1937: —The most interesting development in the transformation into humus of the waste products of a town has recently taken place in Kenya. A factory, erected and managed by the Express Transport Company, is now at work at Nairobi, converting the following wastes into manure: coffee parchment, boma manure, tannery waste, hair, wool and fleshings, horn and hoof, bones, cotton seed residues, chaff, wood ashes and crude limestone. Amazing Results:

When necessary these materials are first finely ground before mechanical mixing, then moistened and composted in pits according to the technique laid down in “The Waste Products of Agriculture.” Nothing, however is left to chance: the proportions of the various ingredients are suitably adjusted; the correct degree of acidity is maintained in the fermenting mass; everything is done to turn out an ideal fertiliser. The conversion takes ninety days, when a rich, finely divided humus of the following composition (expressed in percentages) is produced: Moisture 25.0, organic matter 62.15, nitrogen 1.5, phosphoric acid 1.5, potash 1.5, lime 4.0. The content of soluble humus is 14.0 per cent.; the carbon nitrogen ratio is 15.1. The plant has a capacity of 20 tons a day; in 1934 fhe saies amounted to 3,500 tons; the price at the pits is 14s a ton.

I Commercially Profitable: In a letter, dated Nairobi, September 26th, 1935, the managing director of the company reports that the results obtained on controlled experimental plots of flowers, vegetables, maize, grassland and coffee have been amazing. The Nairobi enterprise started as a simple commercial proposition , suggested by the results which followed the adoption of the Indore. Method on the Coffee Estates:

in Kenya. It proved an immediate success for the simple reasons that the product is just what the soil requires and the price is reasonable. In China, the maintenance of health and happiness of a population of 500 millions depends on the systematic use of organic—vegetable and animal —wastes. carefully composted together by age-old skill and ‘applied, often as a mulch, to the growing crops, to which the system of planting allows access and at the stage in the life of the plant when readily assimilable plant food produces the best results. . . Two Invaluable Principles: The Chinese recognise two ages-old, invaluable principles: (a) Leguminous plants, clover, beans, peas, vetches, lupins, acting as hosts for lower organisms living on their roots, '-are largely responsible for the maintenance o f soil nitrogen, drawing it directly from the air. This was only discovered in Europe in 1888! For example, just before, or immediately after. the rice crop is harvested, fields are often sowed to ‘clover,’ which is allowed to grow until near the next transplanting time (rice is grown in seedbeds and transplanted as seedlings) ; when it is either turned under directly, or more often stacked along the canals and saturated with soft mud dipped from the bottom of the canal. After fermenting twenty or thirty days it is applied to the field.

Another Age-old Principle: (b) The important fundamental principle, only recently understood and added to the science of agriculture, (so far as Europe is concerned) is that of the power of organic matter, decaying rapidly in contact with soil, to liberate from it soluable plant food. It is the working of this principle which Sir Albert Howard has now disclosed to European civilisation, and the practical manner of its employment has been rationalised in his “Indore method.” It is as well to emphasise at this point that Sir Albert Howard’s method of returning to the soil, after treatment, the whole of the animal and vegetable refuse which is produced in the activities of a- community, results in the health and productivity of crops and of the animals and men who feed thereon. He has discovered the principles of the treatment of that refuse. The Famous Indore Process:

A layer of mixed vegetable wastes is lightly covered with farmyard manure in the proportion of 3-1 by volume, followed by a good sprinkling of earth. The sandwich process is repeated until the material in the heap is after fermentation 3ft thick. The layers must be kept moist, not wet, lest the air supply be interrupted. The temperature rapidly rises to about 150 degrees F., and the heaps are turned and watered at intervals. In three months from the beginning the carbon-nitrogen ratio falls from 33.1 in the original mixture to about 21.1, when the humus, which resembles old leaf mould, is ready for the land.

A Natural Process: The process is a partial reversal oi the work of the green leaf. In the cells of the leaf .simple substances obtained from the soil and the atmosphere are synthesised by means of the energy of sunlight into carbohydrates and proteids. The fungi and bacteria in the compost heap practically undo this synthesis until a comparatively stable condition of organic matter is reached in the shape of humus. This is the real food of the soil and of the crop. The second stage in breaking down the materials made by the leaf is only reached when the soil organisms oxidize humus into simple substances once more which can be absorbed by the roots of plants. The wheel of life has then completed a isingle revolution.