52 POPULAR FRUIT GROWING. 



26. What effect does an excess of nitrogen in the soil have upon 

 fruit crops? 



27. What effect does an excess of potasli and phosphoric acid 

 in the soil have upon the fruit crops? 



28. How is the plant food taken from the soil by the plants 

 returned to it naturalb'? 



29. What are some of the formulas for combining and applying 

 different fertilizers to the soil? 



SO. When should manures be applied to fruit lands? 



31. M^hat is the general practice of applying manures to the land? 



32. When should commercial fertilizers be applied and how? 

 32. When is a supply of water for irrigation desirable? 



