182 THE PRINCIPLES OF FLORICULTURE 



the subject of organic matter in soils, Lyon and Fippin 1 

 in their book on soils, state : " These original (carbon) 

 compounds are broken down in the process of decay into 

 other successively simpler compounds. The end of the 

 process is always essentially the same the reduction 

 of the elements to their simplest and most stable forms, 

 the carbon to carbon dioxide, the nitrogen to nitrates, 

 ammonia or even free nitrogen, and the mineral elements 

 to their simple salts. The soil constituents, which are 

 termed humus, mold, peat, muck, etc., merely represent 

 stages in the transition process from the fresh materials 

 to the native elements. There is no single compound or 

 group of compounds which imparts definite characteristics. 

 These are the result of the mixture, and this fact of an in- 

 finitely complex mixture is exceedingly important to keep 

 in mind in considering the effects of the organic matter 

 on the soil. Many of them are acid. Some, as ammonia 

 and marsh gas, function as bases. They react with 

 each other in many ways, and what is more important, 

 they react with the mineral elements of the soil to form 

 organic salts. It is by this union that organic matter 

 has not only a direct effect as a food, but also an indirect 

 effect in releasing food elements from their less soluble 

 mineral combinations. Aside from the production of 

 many complex, organic acids, the two most significant 

 facts of their composition are the per cent of nitrogen 

 present; and the chemical form of part of the carbon- 

 nitrogen which is not a constituent of rocks, is made 

 available in all higher forms of plants through this organic 

 decay process, and these various compounds constitute 

 the soil storehouse of the element, from which it gradually 

 changes over into the available forms." 



1 " Soils " by Lyon and Fippin. 



