NEGATIVE RESULTS ON PHYSIOLOGICAL BALANCE IN SOIL CULTURES

Abstract

The use in the field of the triangular system of determining salt ratios was first attempted by the writer in the growing season of 1918. In the fall of that year, Schreiner and Skinner (10) reported on some of their field work. It has been shown previously by the author (3) that there is some evidence of a physiological balance in the soil solution extracted from the soil and set up in culture jars in the greenhouse. The study reported here was expected to show whether or not a physiological balance exists in the soil solution in situ. It is perfectly evident that such a study as this is considerably more complicated than one in water cultures. The medium of growth, a fertile soil, is indeed very complex, physically, chemically, and biologically. It must also be considered as in a dynamic state, in a condition of change. In spite of the complexities which make correct interpretations difficult, and because there are still possibilities for improvement in the generally accepted plan of applying soil fertilizers, Schreiner and Skinner (10), Lipman and Linhart (7), efforts should be made and are being made to apply the triangular system to field studies. It is quite evident that for these reasons, if not for the fact that our annual expenditure for fertilizer practice is well over a hundred million dollars a year, any and every fertilizer practice should be actively investigated. Such studies involve investigations of the salt requirements of agricultural plants, a study of the mechanism of absorption, and of the uses, functions and modifications of the various ions when finally within the plant.