Estimating the chemical composition of the soil solution of glasshouse soil. 2. Relationships between the compositions of soil solution and aqueous extracts.

Abstract

The possibilities of estimating ECs and K, Na, Ca, Mg, NO3, Cl and SO4 contents of press extracts of glasshouse soils from corresponding analytical data of saturation extracts or 1:5 by-weight extracts were examined through construction of regression equations. The analytical data of saturation and 1:5 by-weight extracts were and were not corrected by multiplication with dilution factors, these being the ratios between the water contents of the soils employed to obtain the extracts and the water contents of the soils at field capacity. The dilution factors used were not derived from actual water contents but from water contents assessed on the basis of loss-on-ignition values. In a number of cases, the estimation technique could be improved through introduction of one or two extra variables, such as the dilution factor, the corrected SO4 content of the extract, the water content of the field-moist soil and the ratio between the mass fractions clay and loss-on-ignition. (Abstract retrieved from CAB Abstracts by CABI’s permission)