"SOILS."

Hawera & Normanby Star, Volume LXV, Issue LXV, 6 September 1913, Page 10

"SOILS."

(Points from a JLecture delivered by Mr 11. A. BroAvne.) In Haw'era and surrounding disrticts our top-soil came from Mount Egmoift, carried by old-time rivers and deposited in low and sometimes swampy lands surrounding the mountain. Later, as the land became more and more elevated, the river again cut down through this old plain, making terraces at each stage of rest in the process. Below the material which came from Mount Egmont was the papa formation —a marine deposit laid down in a shallow sea. This consisted usually of a marl; sometimes a sandstone, and at other times an impure limestone, viz., shellrock. This marine formation came to the surface as one travelled in a N.E. or S.E. direction. "When such soils occur," said MiBrowne, "we usually have hilly country much broken by narrow valleys. The soil was strong, but usually held too much water to be fully productive, and further it was constantly losing plant food by surface wasting. The same causes that elevated the plains also accounted for the greater rise that had taken place in the papa country, and to an increasing degree as one travelled east to the Ruahine mountains. On account of its. origin —viz., as river gravels and sand —and also on account of its elevation, the light land around the mountain was well drained except in such special situations as the Ngaere swamp. _ \Vith cultivation, such light land deteriorated, owing to leaching or the washing out of plant food. Humus or decayed vege- j table watter was everything to the soil, as it gave texture and capacity to j absorb warmth and moisture from the | air. Cultivation destroyed humus, j hence there was no pasture equal to ■ that on the original unploughed soil in our district. Crops at first grew well on the virgin soil, but soon de- j teriorated unless humus was restored j as green or- stable manure, and unless j the soil was kept firm and covered j with crop in winter. Trenching should not be resorted to, neither should constant hoeing be practised. Digging or ploughing should at first be shallow, as no subsoil should be brought up. On an average there were but four to five inches of black soil to work on. They constantly had deep digging or ploughing recommended, but that was j a mistaken idea. If shallow digging j be practised at first, the turf will ] break down more satisfactorily and a greater depth of black soil result. Lime destroyed humus; therefore very little should be added to our soil, although i a little was necessary from time«to, time, or manures would not have pro- j per effect, or, indeed, might be harmtul. Early winter and deep digging followed by an application of several hundredweight of lime per acre was about the worst treatment light soils in this district could receive. With continued cultivation the use of phog-v phates and potash became necessary. Superphosphate by itscir was very effective at first, but without the addition of lime in some form was highly injurious. Basic slag should be substituted, or a light, dressing of lime, say i cwt. per acre, applied previous to the addition of super.; or a mixture of super, and bone dust might be used where either basic slag or lime might be objected to, as in the growing of potatoes. The use of potash was. quite necessary in this district. In garden practice, the lecturer said, he liked to add it to slag in the proportion of five parts slag to one of sulphate of, potash to the surface of the soil in early winter, in preparation for the sowing of a green crop, such as tares. In spring planting, super, could then be safely used to bring on the crop. Nitrates —viz., sulphate of ammonia or nitrate of soda, or better still saltpetre, were best applied in liquid form before or after rain in spring or early summer. The lecturer used a solution of a teaspoonful to the gallon applied to 'the soil around all plants except the legumes. Wonderful results followed when such liquid was sprayjed in the soil around mangels, potatoes, roses, pansies, and all ordinary mixed border plaits. To sum up, the soil in this district could be injured 'by (1) Too deep digging or ploughing'; (2) too much cultivation; (3) the addition of too nrucn lime; and (4^ continued use of super, alone. It required (1) phosphates; (2) potash; (3) nitrates after first cultivation, and (4) a little lime.