Practical Orcharding On Rough Lands. 61 



facjt that without moisture the plant food (no 

 ijnatter how much there might be in the soil) 

 could be of no use, so that moisture becomes an 

 absolute necessity to the growth of plants. 



When we speak of rich and poor soils we 

 should not lose sight of the fact that often times 

 the one we call poor may be just as rich as 

 the other in its stores of plant food, but this 

 plant food is not available. For instance, take 

 the great desert, as we think of and call those 

 irpmense tracts of lands west of the Rockies, 

 which were made productive simply by the ad- 

 dition of moisture. 



We should think of the availability of the 

 plant food in the soil rather than of it as a rich 

 or poor piece of ground. We prefer to say 

 unproductive soil rather than poor or worn-out 

 soil, as it is so often expressed. The one thing 

 that counts for more, not only in the retention of 

 moisture, but in setting free the plant food that 

 is already in the soil, as well as adding to it, 

 is decaying vegetation, or as we say, humus. 

 This is why we find some of our hillsides, as 

 haVe been mentioned, the richer because of the 

 coiistant drifting of the forest leaves, the decay 

 of which has not only added plant food but has 

 increased the humus as well. Humus acts as a 

 sponge that takes up and holds fhe moisture for 



