EXPERIMENT STATION BULLETINS. 



G99 



TABLE S.— RATE AND EXTENT OF SOLUBILITY OF SOILS TREATED WITH A COM- 

 BINATION OF ALL TEN SALTS AND THEN WASHED. FIGURES REPRESENT FREEZ- 

 ING POINT DEPRESSION. 



Treatment. 



Days 



Superior clay, treated 



Superior clay, untreated 



Clay loam, treated 



Clay loam, untreated 



Dark brown silt loam, treated. . . 

 Dark brown silt loam, untreated 

 Dark brown silt loam, treated . . 

 Dark brown silt loam, untreated 



Sandy loam, treated 



Sandy loam, untreated 



Sand, treated. . . . 

 Sand, untreated 







C° 

 .009 

 .006 

 .008 

 .006 

 .009 

 .006 

 .008 

 .007 

 .008 

 .003 

 .003] 

 .003 



C° 



.017 



.008 



.020 



.008 



.02S 



.008 



.022- 



.008 



.020 



.006 



.003 



•**. 



.0031 



C° 

 .023 

 .010 

 .028 

 .008 

 .034 

 .013 

 .032 



010 

 .029 

 .010 

 .003 

 .003 



13 



C° 

 .038 

 .016 

 .050 

 .018 

 .072 

 .036 

 .062 

 .037 

 .052 

 .024 

 .005 

 .005 



20 



0° 

 .040 

 .018 

 .052 

 .019 

 .077 

 .037 

 .073 

 .038 

 .060 

 .027 

 .005 

 .005 



C° 

 .043 

 .020 

 .051 

 .022 

 .078 

 .041 

 .075 

 .039 

 .063 

 .032 

 .006 

 .006 



36 



(:° 



.045 

 .022 

 .O.i2 

 .022 

 .OSO 

 .045 

 .078 

 .042 

 .070 

 .032 

 .006 

 .006 



The above data show very conclusively and strikingly that even when 

 the soils are treated with a combination of salts the rate of solubility is 

 slow and gradual and the process continues for a long time, and that the 

 extent is considerable and much greater than that of the untreated soils. 



The above results also show that w^hen the soils are treated with a 

 combination of all the salts mentioned the phosphates do not inhibit the 

 solubilit}' of the soils as they do when they are added themselves singly. 



On the other hand it must be stated that when (XH^loSO^ and 

 XaCaHsOo are omitted from the combination the extent of solubilit}' is 

 much less than it is w^hen they are present— indicating that it is j)robably 

 the ammonia and the acetate radicals which bring about the ditference. 

 Evidently the phosphates do not control the amount of material going 

 into solution when (^S'HJ.SO^ and XaC^HsC, are present. 



Kate and Extent of SolubilitA' of Experimental Field Soils which have 

 Been Keceiving Fertilizer Treatments in the Usual Manner. Ratio of 

 Soil to Water was about 1 to .7 and Mixture Maintained at Room Tem- 

 perature. 



Having established certain fundamental principles regarding the rate 

 and extent of solubility of soils treated with salts singly and in combina- 

 tion it was deemed important and essential to try to verify these prin- 

 ciples with natural field soils which have been receiving fertilizer treat- 

 ment in the usual wav and whose culture historv and state of fertilitv are 

 known. For this purpose soil samples from the standard experimental 

 fields of the University of Illinois, Cornell University, Ohio lOxperiment 

 Station and Rhode Island Agricultural College were obtained . 



(a) For procuring- these soils the writer is most thankful and very indebted to Dr. Lvon of 

 Cornell University. Dr. Hopkins and Dr. Stewart of the University of Illinois, Professor Ames 

 of the Ohio E.xperiment Station and Director Hartwell of the Rhode Island Experiment Station. 



