IDEAL FERTILIZERS 43 



Too great a proportion of potash makes small foliage 

 and hard, brittle wood, and checks prolificness. Too 

 little leaves the plant and fruit soft in texture, therefore 

 susceptible to disease and decay, limits the starch or 

 sugar content and causes a lack of any high color which 

 may be natural to the fruit. 



Lime is used as mentioned above in strengthening the 

 cell walls and translocation of plant food, for which it 

 is most essential, but its greatest effect upon the plant 

 is indirectly through establishing good soil conditions. 

 We have already taken that up except that the presence 

 of lime causes a profuse development of root hairs which 

 increases the plant's power to feed. 



Magnesia is closely associated with lime. It is one 

 of the plant essentials, vet it is actually noxious to plants 

 even in small quantities unless accompanied by lime in 

 a ratio of about 2:1. Magnesia is important in the de- 

 velopment of seed, acts with the protoplasm in assimi- 

 lating phosphates, and is a constituent of chlorophyl. 

 Those who wish to study this element further should 

 send to United States Dept. of Agriculture, Washington, 

 D. C., for Bulletin No. 1, Bureau of Plant Industry : "The 

 delation of Lime and Magnesia to Plant Growth." 



Sulphur is a constituent of the protoplasm and also 

 of plant protein, that is the nitrogenous compounds, 

 "Its action is important," many plants using more sul- 

 phur than phosphorus. 



Iron is necessary for formation of chlorophyl, though 

 no iron compound is found in either protoplasm or chlo- 



