138 Report of IFarmeks* Institutes 



It lias reacted with certain substances in the soil and has become 

 fixed or held in combination therewith -as part of a product less 

 easily leached, but still available to plant growth by a chemical 

 reversal of the process which we have just considered. This con- 

 clusion is based upon data and is not a deduction from an assumed 

 premise. 



COMPARISON OF FINEST CARBONATE WITH GROUND LIMESTONE 



Let us consider the relative reaction of ground limestone and 

 calcium carbonate from the three sources, as given in Table II. 

 Simultaneously with the treatments of Table II, eight lots of soil 

 were treated with chemically equivalent amounts of commercial 

 limestone of the following mechanical analysis : 



Table III. 



MECHA^^CAL ANALYSIS OF LIMESTONE 



All through 10 mesh 



10 mesh — 2 m.m 30.69 per cent. 



2 m.m. — 1 m.m 18.75 per cent. 



1 m.m. — 1/^ m.m 18.55 per cent. 



Less than i/^ m.m 32.01 per cent. 



The burnt lime, hydrated lime and fine carbonate treated soils 

 were analyzed weekly during an interval of eight weeks ; and, al- 

 though they were exposed, not suffieient rainfall occurred to effect 

 leaching. Seven months after the time these analyses were made, 

 the eight ground limestone soils were analyzed for carbonates. 

 The analyses are given in Table IV. 



COMPARISON BWrWEEN THE ACTIVITIES OF 8 TREATMENTS OF GROUND LIMESTONE 



AND THE AVERAGE OF 4 EACH OF BURNT AND HYDRATED LIME, AND 2 OF 



PRECIPITATED CARBONATE, UPON AN ACID SOIL. 



CaCOs gain per 

 A. 2,000,000 lbs. 

 of soil at end 



Substance applied of 9 months Average 



Ground limestone 20 , 404 



Ground limestone 21 ,264 



Ground limestone 22 . 232 



Ground limestone 20 , 318 



Ground limestone 24, 082 



Ground limestone 22 , 545 



Ground limestone 19 , 459 



Ground limestone 24,445 21,845 



CaCOa gain per A. 2,000,000 lbs. of soil at end of S weeks. 

 Burnt lime, hydrated lime and precipitated chalk 19,387 (10 



treatments) 19, 387 



