H.—34

well to top-dressings of superphosphate. They hold moisture better than the soils of type 4, and are used for dairying and sheep-farming. The clays and clay loams (types 6to 9) are moderately fertile soils originally supporting mixed forest with a large proportion of broad-leaved trees. They are farmed extensively as dairying and grazing land. The semi-mature podsols (types 10 to 12) are more strongly leached and consequently are less fertile. The original vegetation was forest rich in podocarp species and kauri. The topsoils are shallow and the subsoils greyish flecked clays. There is a greater need for lime to accompany phosphate top-dressing of pastures on these soils. The submature and mature podsols (or podsols proper) are strongly leached soils_ showing the characteristic sequence of horizons. A shallow grey topsoil overlies a whitish siliceous horizon, which in turn overlies a pan of clay or cemented sandstone. In some places both humus and iron pans are present in the subsoil. The soils have undergone severe leaching, and in their natural state large areas support a scrub cover of stunted manuka and short rushes. Many of the soils of this group are proving to be valuable farm lands, but large areas are as yet unfarmed partly because of the difficulty of obtaining water. Type 13, derived from lightly consolidated sandstone, is a particularly infertile soil. The topsoil is a coarse to medium sand which readily looses moisture during a dry spell and becomes saturated during rains owing to the humus and iron pans obstructing subsoil drainage. The predominating land forms are broad, flattish ridge-tops and steep V-shaped valleys, but in parts the ridge-tops are narrow and discontinuous. Much of the area is still in scrub, and where the pans are close to the surface farming is impracticable. Types 14 and 15 have generally a light-grey to whitish silt loam topsoil overlying a heavy clay. Agriculturally, these are the most valuable of the gum lands, and when fertilized with heavy dressings of lime and phosphate they support good pastures. Where the topsoil is clay (type 16) the sowing to pasture is more difficult. Types 15 and 16 are so intermingled that they cannot be separated on a small-scale map. Type 17, derived from andesitic rocks, resembles type 15, but the structureless silt loam topsoil is bluish-grey and the clay subsoil is brown. These soils appear difficult to farm, and their problems have not yet been studied. Hill Complexes. —The hills covered with podsolized soils fall into four main divisions Types 18 to 20 are largely a complex of skeletal and immaturely podsolized soils covering the steeper hills. In their natural state the topsoils are highly fertile, but sheet erosion and slipping consequent upon attempts at grassing rapidly lowers the fertility, and as the areas arc difficult to top-dress invasion of second growth takes place rapidly. Areas of these soils are farmed as grazing-land, but they cannot be classified as permanent grassland. Types 21 to 24 are complexes of soils (largely immature podsols) covering the rolling to steep hills. They are used extensively for grazing, but much land has reverted to second growth. Types 25 to 28 cover similar country, but are more leached, being largely semi-mature podsols. Being less fertile, the second-growth problem is more acute. These soils need lime, but the application is too costly. The complex of soils included in type 29 are derived from lightly consolidated sandstone, and are less leached than type 13. The area is more dissected, and the flattish ridge-tops so typical of the latter type are less in evidence. The native vegetation is manuka scrub, and where this has been repeatedly burned the sandy soils have been much wind-eroded. Types 30 and 31, the " gum land hills," are for the most part eroded podsols, and large areas have little or no agricultural value. Type 32 includes poor clay and gravelly clay soils derived from shattered silicifled claystones. The land originally supported scrub with patches of light bush, and although attemps have been made to farm parts of the area the greater part has reverted to scrub and bracken fern. D. Red and Brown Loams. The soils of the red and brown loam group are derived from basaltic rocks. The red loams appear to be formed over scoriaceous rocks where the drainage is good, and the brown loams on flattish basalt sheets where drainage is intermittent. In periods of light rainfall the brown loams drain freely, but, having a low moisture-holding capacity, they dry out during rainless spells. During heavy rains, however, tlie underlying basalt sheet impedes drainage to such an extent that the soil becomes saturated and in many places the water-table rises above the surface of the ground. This feature is most noticeable on the shallower, immature types. Although clay content is high, these soils have a free granular structure which imparts to them the properties of a loam. Being high in iron and alumina, they have the property of rendering' soluble phosphates comparatively unavailable to plants. When adequately manured with lime and phosphates the soils of this group respond to potash. Types 33 to 35 comprise the young and immature soils of this group. Type 33 is a fertile bouldery loam and makes good dairying-land. The boulders are cleared from the surface of the land and employed in the building of stone walls, giving the farms on this type a characteristic appearance. In type 34 the soil is deeper and boulders only break the surface on the slopes. The native vegetation on these two types was generally a rich broad-leaf forest with much taraire, puriri, and kohekohe.

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