SOILS AND FERTILIZERS 117 



Legumes and some other plants grown in acid soil 

 will not thrive well ; but if a little slacked quicklime is 

 added to the soil, or preferably, larger quantities of 

 ground limestone, beneficial results soon follow, for 

 lime neutralizes the acid. Lime does more for vegeta- 

 tion than this. It helps greatly in rendering other 

 plant foods available by hastening the decay of organic 

 matter and rendering insoluble phosphoric and potassic 

 compounds soluble. 



Gypsum, a form of lime, fixes ammonia, hence it is 

 often sprinkled on manure piles to prevent the escape 

 of this substance. (See page 55.) 



