1897.] PUBLIC DOCUMENT — Xo. 33. 221 



solid residue left after its evaporation. The amount of lime 

 noticed in the drainage waters where muriate of potash had 

 been added as a potash source was in every instance larger 

 than where corresponding amounts of high-grade sulphate 

 of })otash were applied. 



In publishing the results of our observations the following 

 conclusions were offered for tlie consideration of farmers : — 



(a) The claim of both muriate and sulphate of potasJt, 

 being economical and efficient forms to supply potash for 

 growing crops, is so well established that no further endorse- 

 ment is called for in this connection. Each form has its 

 special merits loith reference to particular fitness in case of 

 different crops. 



(b) The liberal use of muriate of potash as a fertilizer 

 constituent renders, in cases where the lime resources of the 

 soil under cultivation are limited, a periodical direct applica- 

 tion of lime compounds as a manurial matter advisable. 



(c) Muriate of potash is a safer source for manurial pur- 

 poses upon a deep soil loith a free subsoil than upon a shallow 

 soil with a compact clayish subsoil, on account of a possible 

 accumulation of the highly objectionable chlorides of calcium 

 and magnesium {lime and magnesia) near the roots of the 

 plants; both are known to prevent a healthy development of 

 the root system. 



Repeated observations in the field and in the laboratory 

 tend to confirm the above-stated conclusions ; chloride of so- 

 dium (common salt) behaves in the same way as the chloride 

 of potassium, — a fact which is readily proved by adding to 

 any kind of a soil which is free from the chlorides of cal- 

 cium some ground chalk and common salt, and after a week 

 or so collecting and analj^zing the percolating water; the 

 presence of carbonic acid favors greatly the reaction ; no 

 good agricultural soil is free from carbonic acid or bicarbon- 

 ates of lime and magnesium. 



