THE EFFECT OF FERTILIZER SALTS TREATMENTS ON THE 

 COMPOSITION OF THE SOIL EXTRACTS. 



Technical Bulletin No. 45 



C. H. SPURWA\% SOILS SECTION_, MICHIGAN AGRICULTURAL EXPERIMENT 



STATION. 



Historical. 



Since the time of Liebig and Boussingault agidcultural investigators 

 have manifested great interest in the effects of fertilizer salts on soils and 

 crops. Considerable work has been done along this line and the liter- 

 ature on the subject is very voluminous, so that practical difficulties do 

 not permit of a complete review here. Sufficient reference material is 

 given, however, to show the trend of results so far obtained. 



Storer (29) gives results from Boussingault's work showing that 

 CaS04 liberates P, K, SiO„, Mg, S and CI from the soils experimented 

 upon, and in one case Na and oxides of Fe, Mn and Al collectively, 

 because greater quantities of these elements were found in the ash of 

 clover grown on a treated soil than were found in the same crop from 

 the same kind of soil untreated. . Several other investigators have studied 

 the power of CaS04 and other chemicals to liberate K from soils and 

 soil forming rocks, with various results. Bradley (4) working on some 

 Oregon soils, found that gypsum increased the solubility of K in the 

 soils and also in feldspar but the effect of lime in this respect was slight. 

 Curry and Smith (8) claim increased solubility of potash in some New 

 Hampshire soils by use of NaCl, NaNO;^, and Na^COa, while lime and 

 CaCOg had practically no effect. Similar results were obtained from 

 Na salts by Tressler (30), who also found that CaSO^ liberated K from 

 some soils, and the effect was more marked on a clay than on either a 

 silt or sand. McMiller (24) also claims that gypsum liberates K from 

 certain Minnesota soils, and Wheeler (32) gives data to show that NaCl, 

 NaNOg and Ca salts may liberate some K from soils. Some investigators 

 obtained results differing from those just stated. Plummer (26) found 

 that CaH2(C03)2 did not increase the solubility of K in biotite, mus- 

 covite, orthoclase or microcline. That lime does not increase the avail- 

 able K in soils is also stated by Gaither (13). Fraps (11) claims that 

 NaoSO.j, NaNOg or other salts have little effect on the solubility of K 

 in soils, but that CaCOg and organic matter liberate K to some extent. 

 Briggs and Breazeale (i), hoAvever, state that Ca(0H)2 had practically 

 no effect in liberating K from pegmatite, orthoclase or granitic soil. 

 These authors also found that the solubility of K in orthoclase was 

 depressed by gypsum. Lyon and Bizzell (19) also place little emphasis 

 on the effect of lime in liberating K from soils. These results seem to 

 show that the solubilily of K in potash bearing rocks and soils is in- 

 creased very slightly if at all by hydrated lime, lime or CaCOg but that 

 in this respect CaSO^ and Na salts act differently on different rocks and 



