Soil Formation

Soil is the thin layer of material covering the earth’s surface and is formed from the weathering of rocks. It is made up mainly of mineral particles, organic materials, air, water and living organisms—all of which interact slowly yet constantly.

Soil minerals are produced from rocks (parent material) through the processes of weathering and natural erosion. Water, wind, temperature change, gravity, chemical interaction, living organisms and pressure differences all help break down parent material. The types of parent materials and the conditions under which they break down will influence the properties of the soil formed. 

The pages here provide some basic information about the parent materials and climate setting within which the soils of Tuvalu have formed.  These soils are very weakly developed on young, porous and highly calcareous sands and gravels, and characterized by their alkalinity, immaturity of profile development, low water retaining capacity and by a lack of clay and natural fertility. Fertility depends very much on the proportion of organic matter incorporated into the substrate, either naturally or artificially, and upon the size of the constituent coralline parent material.

They are usually deficient in most of the important nutrients needed for plant growth (e.g., nitrogen, potassium and micronutrients such as iron, manganese, copper and zinc) (Morrison 1987; SOPAC 2007).

Information about land use and major soil related projects is also provided.

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