1918] Lipman-Gericke : CaCO s and CaS0 4 an, I Soil Solution 279 



mining how CaCCX. or CaS0 4 will affect the soil reactions and the 

 precipitation or the greater solution of given ions in any soil. This 

 marked disparity between the nature of soil reactions and their results 

 in different soils, seems to have been but slightly appreciated, if at all. 

 among soil investigators. We therefore find, on the one hand, the 

 iterated and reiterated statements in our text-books respecting the 

 effect that lime or gypsum, or both, exert on the available potash 

 supply in the soil solution; and, on the other hand, such statements 

 as that by Briggs and Breazeale to which we have made reference 

 above, which deny directly or inferentially the effectiveness of lime 

 and gypsum, in that direction, for a certain soil or a certain mineral ; 

 and through the absence of comparison with other soils imply the 

 denial of the existence of such effects in general. As is freqently the 

 case in all matters, the truth lies between these extreme views. Potas- 

 sium from the soil minerals is rendered soluble in greater quantity 

 than normally by applications to the soil of both CaC0 3 and CaS0 4 

 in some soils, but not in others. Of the three soils which we have 

 studied, two seem to us to show clearly the former and one the latter 

 effect. 



Working also with only one soil (Dunkirk clay loam), Lyon and 

 Bizzell. 8 by the indirect method of studying drainage water from 

 lysimeters, and by the possibly direct method of studying absorption 

 by plants, showed, prior to the work of Briggs and Breazeale, that 

 liming of soils does not increase the potassium content of the drainage 

 water, or of plant substance. But, it should be noted too, that in other 

 respects their results are also at variance with ours. For example, 

 they found that the application of lime to soil (to be sure it was CaO 

 and not CaC0 3 ) did not increase, and in general, actually depressed 

 the amount of calcium in the drainage water and hence probably, 

 though not necessarily, in the soil solution; whereas we have found 

 the calcium content to be higher and distinctly so in all soil extracts 

 hut one from soils treated with either lime or gypsum regardless of the 

 soil's nature. In our opinion, these apparent disagreements are really 

 only manifestations of the marked differences characterizing the 

 physical-chemical systems which we call soils in equilibrium with 

 water. When we consider soils as such systems, dynamic and not 

 static in nature, and in addition apply to them the Van Bemmelen 

 formula for absorption by colloids, it is not difficult to understand the 



s Lyon, T. L., and Bizzell, J. A., Calcium, magnesium, potassium and sodium 

 in the drainage water and from limed and unlimed soils, Jour. Amer. Soc. Agron., 

 vol. 8, p. 81, 1916. 



