New buffer pH method for rapid estimation of exchangeable acidity and lime requirement of soils 1

Abstract A new buffer pH method (BpH) for the rapid estimation of unbuffered salt‐exchangeable acidity (ACe) and lime requirement (LR) has been developed. The buffer reagent, consisting of sodium glycerophosphate, acetic acid, trletlianolamine, ammonium chloride and barium chloride, was useful within the pH range 3.8 to 6.6. Delta values from BpH were converted into buffer pH acidity values (AC) and calibrated against ACe of 91 mineral soils and 100 acid Histosols. The correlation coefficients between AC and ACe were 0.966 and 0.956 for the mineral soils and Histosols, respectively. The corresponding regression equations in terms of meq/100 cm were ACe ‐ ‐0.54 + 0.96 AC and ACe = ‐7.4 + 1.6 AC for mineral soils and Histosols, respectively. To predict lime requirement of mineral soils a curvilinear equation was required. The equation, LR in meq CaCO3/100 cm3 = 0.1 (AC)2 + AC, was tested successfully against rates of lime carried out under laboratory conditions and against crop response in the greenhouse. F...

[1]  C. E. Evans,et al.  A Rapid Method for Measuring Lime Requirement of Red-Yellow Podzolic Soils1 , 1962 .

[2]  Rathje.  Jackson, M. L.: Soil chemical analysis. Verlag: Prentice Hall, Inc., Englewood Cliffs, NJ. 1958, 498 S. DM 39.40 , 1959 .

[3]  E. J. Kamprath.  Exchangeable Aluminum As a Criterion for Liming Leached Mineral Soils1 , 1970 .

[4]  A. Mehlich.  Uniformity of soil test results as influenced by volume weight , 1973 .

[5]  E. O. McLean,et al.  Buffer Methods for Determining Lime Requirement of Soils With Appreciable Amounts of Extractable Aluminum , 1961 .

[6]  R. K. Schofield.  Rapid methods of examining soils. II. The use of p–nitrophenol for assessing lime status , 1933, The Journal of Agricultural Science.

[7]  I. C. Brown.  A RAPID METHOD OF DETERMINING EXCHANGEABLE HYDROGEN AND TOTAL EXCHANGEABLE BASES OF SOILS , 1943 .

[8]  M. Peech.  Hydrogen-Ion Activity , 1965 .

[9]  A. Mehlich.  Use of Triethanolamine Acetate‐Barium Hydroxide Buffer for the Determination of Some Base Exchange Properties and Lime Requirement of Soil , 1939 .

[10]  T. Yuan.  A Double Buffer Method for the Determination of Lime Requirement of Acid Soils , 1974 .

[11]  A. Mehlich.  RAPID ESTIMATION OF BASE‐EXCHANGE PROPERTIES OF SOIL , 1942 .

[12]  A. Mehlich.  Uniformity of expressing soil test results a case for calculating results on a volume basis 1 , 1972 .

[13]  C. M. Woodruff,et al.  TESTING SOILS FOR LIME REQUIREMENT BY MEANS OF A BUFFERED SOLUTION AND THE GLASS ELECTRODE , 1948 .

[14]  A. Mehlich,et al.  Advances in soil test methods foe copper by atomic absoeption spectrophotometry 1 , 1975 .

[15]  C. E. Evans,et al.  Lime response as related to percent Al saturation, solution Al, and organic matter content. , 1970 .