WINTER MEETING. 



191 



to the same degree before beginning, show^ a difference of more tkan 

 a quart table of water per cubic foot in favor of the new soils. 



3. This added vegetable matter makes the soil warmer and quicker 

 than before, notwithstanding the increased amount of water held, for 

 the color is made darker, enabling it to absorb more of the sun's heat, 

 and the decaying of this vegetable matter produces sensible heat in 

 the same way (although to a much less degree ) that the decaying of 

 the manure in hotbeds maintains a high bottom heat. It has been ob- 

 served that frosts did no damage on soils rich in humus and of dark 

 €olor, while those similarly located and adjoining, which had been de- 

 pleated of humus by cultivation, had been visited by killing frosts. 



4. This humus is a powerful solvent of the inactive potash, phos- 

 phoric acid and silica in the soil. It was found that in soils well sup- 

 plied with humus there were 1500 pounds of phosphoric acid, out of 

 a total of 8750 in the soil, combined with the humus, and 1000 pounds 

 of potash, out of a total of 12,250 in the soil, combined in the same 

 way. In soils poor in humus there was nearly as much total phos- 

 phoric acid and potash, but less in available forms. 



COMPARISOX OF THE APPROXIMATE FERTILIZIXG MATERIALS COXTAINED IX AX 

 ACRE RED CLOVER, COW-PEAS AXD CRIMSOX CLOVER. 



In the Eastern states, where the farmers and orchardists depend 

 largely upon commercial fertilizers for their supply of plant food, it is 

 found necessary to apply barnyard manure or grow clover every four 

 or five years to keep up the supply of vegetable matter. 



It is not possible for the commercial orchardist to cover his land 

 with barnyard manure, even though he desired to do so. Hence for 

 the vegetable matter and a supply of available nitrogen, potash and 

 phosphoric acid he is compelled to rely upon some green manuring 

 crop and tillage. For this green manuring practice and scientific ex- 

 periments have clearly demonstrated that no plants will produce as 

 prompt and satisfactory results as clover or cow-peas. 



