AbstractsEarth & Environmental Science

Effects of heavy applications of lime to soils derived from volcanic ash on the humid Hilo and Hamakua coasts, island of Hawaii

by Alan James Rixon




Institution: University of Hawaii
Department:
Degree: PhD
Year: 1962
Keywords: Liming of soils; Sugarcane  – Hawaii; Soils  – Hawaii  – Hawaii Island
Record ID: 1512152
Full text PDF: http://hdl.handle.net/10125/11340


Abstract

Typescript. Bibliography: leaves 135-148. xii, 148 leaves 3 mount, col. ill., mount. diagrs., tables The humid tropics provide an environment conducive to active alteration of geological material. Volcanic ash with its high porosity and extensive specific surface area weathers rapidly under these conditions. There is a heavy loss of silica and bases and an accumulation of iron and aluminum compounds. The resulting soils have a low content of crystalline clay minerals in the clay fraction, an acid reaction and a low base status particularly in regard to calcium. Soils derived from volcanic parent material are of considerable agricultural importance in the humid tropics. Abundant sources of lime in the form of coral stone often occur in the vicinity of these acidic soils. Thus an understanding of the effects of lime application to such soils is desirable. In their natural conditions the soils of the humid tropics support a dense vegetation. Lumber is a natural product from such locations. Where there is favorable topography the natural vegetation is often replaced by agricultural crops and pastures. Modifications, which may include liming of these soils are often necessary to obtain the most efficient production of these introduced species. Liming in the temperate regions has been intensively studied. At this stage there is a fairly comprehensive knowledge of the effects of liming on the soils of these latitudes. Frequently, these studies have been conducted with soils having a high percentage of crystalline clay minerals in their clay fraction. Only sparse and fragmentary knowledge regarding the effects of liming in the humid tropics is available. The existing information is often concerned with relatively light applications of lime. The soils derived from volcanic ash, in this study, are located on the humid Hamakua and Hilo coasts on the Island of Hawaii. They are used for growing sugar cane. A series of lime phosphate experimental plots has been installed on the Hilo and Hamakua coasts, with tie aim of increasing the yields of sugar cane. The high aluminum content and low pH values of these soils present the possibility that toxic amounts of aluminum may be a limiting factor in plant growth. These soils are highly amorphous, having a high capacity to fix phosphates, thus making them sparingly soluble for plant use. It is suggested that benefits to sugar cane, because of heavy liming of these soils, are due to either the reduction of the toxic effects of aluminum or improved phosphate availability. In the latter case, applied lime may produce a liberation of fixed phosphate, or reduced fixation when phosphatic fertilizers are added simultaneously, or a combination of both these effects could occur. Accordingly, in the present study, the effects of heavy lime application on the soil properties, leaching losses, and presence of various elements in sugar cane tissues were investigated. Inasmuch as little information in regard to soil modifications and sugar cane response to heavy lime applications is…