

122 AGRICULTURE ON THE PACIFIC SLOPE 



Food. We shall learn later on (pages 139-148) 

 that the kind of mineral food the plant receives affects 

 its growth arid general appearance. Thus abundance 

 of nitrogen causes a particularly^ strong, rank growth, 

 and gives a deep green to the leaves, while phosphorus 

 especially helps the production of flowers and fruit. 

 It is a well-known fact that (starving a plant makes it 

 flower and fruit much earlier, though, usually, not so 

 abundantly. A tree severely injured will sometimes 

 bear a very abundant crop of small fruit before it dies. 



Too much of any one substance in the soil may make 

 it unfit for some plants, while others grow well in it. 

 Thus, asparagus will stand so much salt that the weeds 

 in an asparagus bed may~~be killed by sprinkling on 

 salt, while the asparagus itself is not injured. 



Soil that is too alkalinejor ordinary crops may still 

 raise stock beets and alfalfa, while land too alkaline for 

 these crops will grow salt-bush, which makes good fodder. 



Not only the chemical, but the physical nature of 

 the soil and of the subsoil (whether hardpan or porous) 

 is of importance. Find out what kind of land is con- 

 sidered best for _the^ various crops with which you are 

 familijD. Try also to learn to judge the land by the 

 & wild plants which grow on it. Plants show the char- 

 acter not only of the soil, but also of the climate. 



Warmth. At the beginning of the chapter it was said 

 that to give the plant too much of any of the things it 

 needs is as bad as to give it too little. This is, perhaps, 



