TYPES OF SOIL

Nelson Evening Mail, Volume LXXII, 26 January 1939, Page 12

TYPES OF SOIL

INFLUENCE OF VEGETATION , DEVELOPMENT AND DECLINE The type of soil formed in any locality is more influenced by the type of vegetable cover w’hich it originally carried than by the basic minerals. Thus, out of identical geological deposits there is produced, in the same region, greybrown podsolic soils where forests have stood, and prairie soils where the cover has been grass or tussock growth. It may be truly said that soil-building processes have more influence on the type of soil produced than the raw' materials out of which the soil is made. Early settlers in New Zealand recog- j nised this fact, although, perhaps un- j consciously, w hen they showed a pre- . I ference for bush lands growing certain | types of trees. . It is also to be noted in the early ; : stages of soil-building processes, there | j is formed what is called a “young” soil; \ in later stages a “mature” soil is produced. and finally a “senile” or degraded soil results. All these stages of soil : life, or development and decline, can be seen in most countries, especially 1 in those old lands, such as Australia. Mongolia and Northern Africa. In New r Zealand, and especially in the volcanic areas, the soil is "young.” in that much of it w'as only u. process of ( formation by the forests w'hen we. occupied the land. In many instances we destroyed this soil-building factor, the forest, before it had completed its work, and must now find means of preventing the soil from becoming prematurely