New York Agricultural Experiment Station. 75 



merits of limestone rock are seldom in need of liming. Soils with a 

 light color, gray, grayish brown or yellowish shades are usually in 

 need of liming. Whenever serious difficulty is experienced in grow- 

 ing good crops of common red clover, then the need of additional 

 lime carbonate is strongly indicated. Its use may sometimes be 

 profitable before such a condition as this is reached. 



The litmus test for soil acidity is made as follows: Obtain a ball 

 of moist soil about the size of the fist, break it open and insert a 

 double thickness of blue litmus paper (obtainable at any drug store). 

 Press the ball firmly together and allow to stand a half hour. If at 

 the end of this time the paper in contact with the soil has distinctly 

 changed to a pink color there is positive evidence of acidity in the 

 soil and it can be safely assumed that benefit will follow liming. 

 If there is only a very faint change of color it is not always safe to 

 say that lime can be profitably used. If the paper remains of a deep 

 blue color, or if perhaps the blue color is intensified, then it is not 

 likely that limestone can be used with profit. Of course it will not 

 do to make only a single test, but a number should be made in dif- 

 ferent parts of the field and it is better to examine the subsoil as 

 well as the surface. 



FINALLY. 



It is to be understood that lime does not take the place of fer- 

 tilizers and manures, but supplements them. Without sufficient 

 lime carbonate in the soil any other treatment must fall short of 

 its possible attainment. The benefits following its use are mild 

 and lasting rather than phenomenal and short lived. With many 

 crops the direct effect of an application of lime in any form does not 

 more than pay for its cost; but its great value consists in making 

 it possible to grow such crops as clover and alfalfa, and in greatly 

 improving the quality and yields of meadows and pastures. It is 

 the key to the great storehouse of nitrogen in the air. By the heavier 

 sods and crop residues and the increased quantities of manure pro- 

 duced as a result of larger crops it is possible to supply the soil in a 

 natural way not only with the nitrogen needed by plants, but with 

 liberal amounts of organic matter which is so necessary for the 

 liberation of mineral plant food and for good physical condition of 

 the soil. 



A list of companies in New York State producing ground lime- 

 stone or marl for agricultural use is given on p. 76. 



Ground limestone of good grade (the total passing a sieve with 

 ten meshes to the linear inch, and containing at least 90 per ct. 

 carbonates) can be obtained in bulk, carload lots, f. o. b. quarries, 

 at $1 to $2 per ton. The added freight charges make this $1.50 to $3 

 per ton delivered to the farmer's railway station. For most soils 

 in this state ground limestone should be used in liberal quantities, 



