AGRICULTURAL INSTRUCTION.

Gisborne Times, Volume XXVII, Issue 2628, 9 October 1909, Page 5

AGRICULTURAL INSTRUCTION.

LECTURE BY MR. LOTEN

Mr. E. G. Loten, Agricultural In- j structor for the Hawke’s Bay Education Board, met the teachers of the J town and suburban schools at the Qis- . J borne School yesterday, and delivered || a most interesting address on the sub- * ject of soil and soil formation. He said that the term soil was applied to the upper stratum of the crust of the earth, which was specially adapted to the maintenance of plant life, inasmuch as it contained all the constituents necessary for the growth of plants. Soil consisted of two parts—the organic portion, which couid readily be burnt away, and the inorganic portion, which was left behind after the former part was removed. The organic part was made up of the remains of animals and plants which had lived in or upon the earth, after death becoming incorporated with the soil. It was to these remains and the chemical changes that took place during their decay that the soil owed most of its fertility. The quantity of organic matter varied greatly in soils. In peaty soil it formed as much as 65 per cent, of their | whole weight, while in good arable land % about 7 per cent, of humus was found, of which the chief constituents were humic acid-and compound of water and ammonia. The inorganic portion of the soil consisted of salts, both soluble and insoluble. From the soluble substances plants obtained a greater part of their solid ingredients, contained in the ash which they left when burned away. The power of the sun was the agency that accomplished th» work of creating that loose substance known as soil, and also was the source from which energy was derived, directly or indirectly. The chief factors in soil formation, were water, atmosphere, and animal life. The most important of these was water, the erosive and transporting power of which was due to chemical and mechanical action. The rain in passing from the clouds to the ground absorbed oxygen and other matters, which prepared the water to corrode the surfaces of the rocks, which eventually crumbled away. The chemical work, however, was a mere nothing when compared with the mechanical action. Organic life was a sile-ift butpotent agent in soil formation; whoreevor rocks had been acted upon by the weather, vegetation crept in, and the tiny roots found their way into the innumerable crevices of the rocks. The large roots often split asunder large pieces of rock, and in this way rendered the rock more liable to the other disintegrating influences. The _ micro organisms, ivhich were of such importance to agriculture, were of two sorts —fist, those which oxidised nitrogenous substances, thereby forming nitric acid, and. second, those which reduced nitirc acid to ammonia or to . free nitrogen. Animal life also did a fair share of geological work, ants and earth worms doinac an enormous amount oi work in that way. Darwin had calculated that in many parts of England more than ten tons of earth pass through their bodies annually, and is brought to the surface on each acre of land. Thus, in a few years the whole superficial bed of soil "would pass through their bodies in a few years. Many of the immense limestone beds, concluded Mr, Loten. were accumulated from the shells of mollusks and the skeletons of starfish and other lime secreting animals. Dir. Loten’s lecture was most attentively listened to. and at the close he was thanked by the teachers. Last evening he delivered a similar lecture to a good gathering of the country teachers in the Matawhero School.