CHAPTER XII 



THE CONSERVATION OF THE PRODUCTIVE CAPACITY 

 OF WOODLAND SOILS 



No kind of soil can be said to possess inherent productive 

 energy. The productivity or productive capacity of any land 

 for agricultural or sylvicultural utilization is a mere potentiality ; 

 whilst the light and warmth of the sun are the kinetic influences 

 which set this in action, and enable it to sustain organic life. 



Only those kinds of woodland crops can be grown prudently 

 and economically, which merely utilize, but do not exhaust, the 

 productive capacity of the soil, which in fact, to use a financial 

 simile, live on or within the annual income obtainable from 

 the land, and do not encroach upon its productive capital. 

 Whenever the form of crop is such as fails to safeguard the 

 productive capacity of the soil, any immediate advantage 

 promised by its retention is dearly bought at the cost of 

 ultimate deterioration of the land to a greater or less extent. 

 The rewooding of such deteriorated soils is often an extremely 

 difficult task, more especially when they are of a decidedly 

 limy nature. 



I. Maintenance of, or Increase in, the Quantity of 

 Mineral Nutrients available throughout the Soil 

 in the form of Soluble Salts. 



So far as concerns the actual withdrawal of sulphur, potash, 

 magnesia, lime, iron, and phosphoric acid the most essentially 



