Radical soil management for Australia: A rejuvenation process

Particularly in the Australian context, this concept paper argues that much of the continent has highly weathered soil of great antiquity with poor agricultural productivity, that much younger soil also exists in juxtaposition, and that certain anthropogenic processes, such as soil inversion or any other radical soil management, can rejuvenate soil for increased productivity. Younger soil occurs wherever there is an accumulating environment where relatively young materials are being deposited (e.g., alluvium), or eroding circumstances where less weathered materials become exposed such as following colluvial or deflation activity. Depositional materials are not necessarily younger when they result from redistribution of highly weathered materials such as by aeolian activity. Certain soil types may be considered as self-rejuvenating if they exhibit self-mulching and pedoturbation characteristics whereby less weathered subsoil material is brought up into the soil. Soil rejuvenation events, through a variety of processes, therefore occur naturally in Australia, as they do elsewhere. With respect to wheat production for illustrative purposes, it is argued that young or rejuvenated soil is more agriculturally productive, and that certain anthropogenic processes (such as the addition of clay or bringing subsoil clay to the surface) that rejuvenate soil can be brought about by radical soil management.