SOIL FERTILITY

Wairarapa Times-Age, 3 August 1938, Page 3

SOIL FERTILITY

IMPORTANCE OF HUMUS. BRITISH SCIENTIST'S VIEWS. “The most important factor in the restoration and maintenance of soil fertility is to make the soil live,” said a noted British scientist, Sir Albert Howard, in an address given before a group of prominent agriculturists in London.

In opening his address, Sir Albert said: “The results of my studies can be summed up in the following principles: —Soil fertility involves a combination of three things: (a) The maintenance of an active and vigorous soil population, among which the earthworm plays a vital part; (b) a suitable physical condition, sometimes spoken of as the crumb structure; (c) the continuous replenishment of the soil solution for the roots of crops.”

Of these three factors, the biological aspect is the most important—the first thing is to make the soil live, according to this authority. He places the physical factor second and the chemical last; yet in New Zealand the improvement of fertility by chemical means in the form of artificial fertilisers is not only placed first, but it is usually the only factor considered, more Especially in pasture improvement. Of course, under the Dominion system of stock grazing grassland the year round, the waste products of the animal are applied to the land,, and in this way a stimulus is given to the life in the soil, of which more will be said later.

Sir Albert Howard was probably too sweeping in his condemnation of artificial fertilisers, particularly when he stated that “the attempts which have been made to short-circuit nature by the use of artificial manures have failed. Heavy dressings of artificials destroy the earthworm population.” As a matter of fact, Dr. Crowther, of the Rothamsted Experimental Station, challenged Sir Albert’s observation on the effect of fertilisers on earthworms, and quoted experiments made at Rothamsted which showed that, on land where some 40 tons of artificial fertilisers had been applied to each acre over a term of 80 years, there was no evidence that the earthworm population was less than in farming areas. Sir Albert Howard remarked: “My experience has been—and I do not stand alone in this —that properlygrown grass and clover (on humussufficient soil) is an important factor in increasing the disease resistance of the animals which feed on it. We cannot possibly expect to keep our livestock healthy if they continue to be fed on grass produced by old, pot-bound dead sod. The control of animal diseases by the conventional methods of veterinary science will, I am sure, be largely unnecessary once we provide the animals with really high quality grass and other food and pay proper attention to the breed and to the general hygiene. If we start with sound stock, and feed and care for animals properly, disease will fade into insignificance. The first condition, however, is to raise the fertility of the soil by means of humus, and to make it live. A living, healthy soil, abundantly provided with earthworms, will mean healthy animals.”