MANURES AND HUMUS IN SOIL. 



I have dwelt so long on the subject of carbonate of 

 lime that I must now take occasion to emphasize that 

 lime is not sufficient plant food. Lime promotes 

 bacterial life and saves plant food and makes it 

 available and helps it accumulate. After one has his 

 soil well filled with carbonate of lime, then he is 

 ready to begin to build it. If nature had filled that 

 soil with carbonate of lime ages ago she would have 

 gone on with the work and stored it with vegetable 

 matter, humus. Then there would be now in that 

 soil nitrogen and bacteria in abundance, and prob- 

 ably a,bundant phosphorus and potash as well, since 

 phosphorus is nearly always in pretty good supply 

 where carbonate of lime is plentiful in the soil. 



Let us get clearly in mind here that liming is only 

 a step in the soil-building process ; it is the founda- 

 tion of things, as it were. And now again let us re- 

 peat that soils are living things. The productive- 

 ness of the soil is dependent upon the numbers of 

 bacteria found therein. Bacterial life is not abun- 

 dant in soils that are deficient in humus, vegetable 

 matter. 



Stable Manure Best Source. — The very best source 

 of humus is stable manure. If the reader has fol- 

 lowed the story of Woodland Farm, related in the be- 

 ginning of this book, he will have in mind the great 

 part that manure played in building the alfalfa 



(150) 



