Note 68 — Chapter VII · THE MINERAL CONSTITUENTS OF THE SOIL SOLUTION.[40]
Reading edition
See Electrical instruments for determining the moisture, temperature and soluble salt content of soils, by L. J. Briggs, Bull. No. 15, and the electric bridge for the determination of soluble salts in soils, by R. O. E. Davis and H. Bryan, Bull. No. 61, Bureau of Soils, U. S. Dept. Agriculture.