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SOIL SURVEY. Land Utilization Committee. —Sir Theodore Rigg, Director, Cawthron Institute (Chairman); Mr. A. H. Cockayne, Director-General, Department of Agriculture ; Mr. E. J. Fawcett, Assistant Director - General, Department of Agriculture; Mr. R. B. Tennent, Director, Fields Division, Department of Agriculture ; Mr. R. P. Council, Land Utilization Officer, Department of Agriculture ; Professor W. Riddet, Massey Agricultural College ; Mr. G. A. Pascoe, Factory Controller, Department of Industries and Commerce ; Dr. L. I. Grange, Director, Soil Survey Division, Department of Scientific and Industrial Research; Mr. R. G. McMorran, Under-Secretary, Lands and Survey Department; Mr. F. R. Callaghan, Chief Executive Officer, Plant Research Bureau, Department of Scientific and Industrial Research ; Dr. I. W. Weston, Agricultural Economist, Canterbury Agricultural College ; Mr. F. J. A. Brogan, Assistant Secretary, Department of Scientific and Industrial Research (Secretary). REPORT BY DIRECTOR (DR. L. I. Grange). The general soil survey of New Zealand, commenced during the previous year, has been continued. Field-work on the soils of the North Island is now completed and a comprehensive legend containing 131 main soil types compiled. In the South Island, mapping for the general soil survey has been carried out chiefly on the high-country runholds at the headwaters of the Waitaki, Rangitata, Rakaia, Waimakariri, and Waiau rivers. In the Waikato lowlands a detailed survey now covers the district extending east from Hamilton to Motumaoho and south to Cambridge. Towards the close of the year, classification of soils in the South Otago and Southland lowlands was commenced with the object of providing information on soil conditions for flax growth. The chemical work of the Division, which was formerly located at the Cawthron Institute, Nelson, at the Dominion Laboratory, Wellington, and at a small laboratory of the Division in Wellington, has now been unified into one laboratory, situated in Wellington. General Survey, North Island. In the general survey of the North Island, 131 main soil types were identified by their field characteristics and were classified into nine groups : Recent soils, Rendzina soils, yellow-grey loams, podsolic soils, brown loams, ground-water soils, saline soils, skeletal soils of the steep slopes, and mountain soils. Wherever sufficient evidence was available, the types within each group were assembled into stage divisions according to the development the soil has reached. Soils of the moderately-steep hills were mapped as phases of closely-related types covering the rolling country. The Recent Soils. The Recent soils are derived from alluvium, which is still being added to from time to time by present-day floods and from recent volcanic showers. The Recent soils from alluvium floor the main valleys ; they are for the most part fertile loams and clay loams, and are most extensively developed in the Hawke's Bay, Gisborne, and Manawatu districts. Less-fertile gravelly and sandy Recent soils from alluvium and poorly-drained types are widely scattered throughout the Island. The Recent soils from volcanic ash are of three main types : The fertile sandy loam of the Rotomahana mud, the gravelly sand formed from Tarawcra lapilla) (both of which were erupted in 1886), and the sandy loam ash that covers the roughly-circular area of about thirty miles radius around Ngauruhoe Volcano. These ash deposits are important in that they cover older pumice soils which are free from bush sickness wherever a thin layer of the recent ash is present. The Rendzina Soils. The Rendzina soils are lime-humus soils developed on limestone rocks and are confined mainly to North Auckland. They have deep dark-grey clay topsoils with a strong crumb-structure, and heavy brown and gray mottled subsoils containing free calcium carbonate. These fertile soils are used for dairying and sheep-farming. Related soils occur north of Raglan and in. Hawke's Bay. The Yellow-grey Loams. The yellow-grey loams are confined to the lower rainfall areas (35 in. to 50 in.) of Hawke's Bay, Wairarapa, and Manawatu, the native vegetation being light forest, scrub, and bracken fern. They are formed largely from calcareous mudstone and argillaceous sandstones. The true yellow-grey loams are fertile soils with a high pH and are well saturated with bases. In their mature stage they show a grey A 3 horizon and a marked accumulation of clay in the subsoil, but the topsoil is still high in bases. Other soils included tentatively in this group are derived from indurated mudstone and sandstone. They are light in texture and much less fertile, being moderately acid and less saturated with bases. The Podsolic Soils. The podsols are in two main divisions : The podsolic soils derived from pumice ash, and those derived from sedimentary and massive acid igneous rocks. The Pumice Podsols. —The pumice podsols are developed on comparatively recent showers of pumiceous volcanic ash covering the central North Island plateau and contiguous areas. Of these showers, the Taupo and the Kaharoa are the most important. These soils are peculiar in that normal leaching is proceeding simultaneously with geological weathering of raw pumice present in all parts of the soil profile. Mineral deficiency diseases (bush sickness) in stock are a feature of the pumice soils.

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