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 abundant 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 
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