Viljavuusanalyysin tarkkuudesta

Authors

• Osmo Mäkitie Maatalouden tutkimuskeskus, Maantutkimuslaitos, Helsinki

DOI: https://doi.org/10.23986/afsci.71439

Abstract

The accuracy of soil testing analysis in routine work, without any control of duplicate determinations, has been investigated. The soil testing method employed in Finland (acid ammonium acetate, pH 4.65) uses a bulk amount of soil for leaching. Neither thispreliminary measurement nor the extraction cause significant disturbing errors (Table 1), but the flamephotometric and colorimetric determinations of nutrients need careful work. In these quick-test determinations it is very necessary to keep the instruments at the right level when comparing sample solutions with standard solutions. The percentage errors are high, especially in nutritionally poor soils, but they are sufficient for the usual practical cultivation (Tables 2—3). The practical errors in routine soil testing analysis are; pH ±2.2 %, Ca ±5.9 %. K ±7.2 % and P ±9.7 %. For field experiments and scientific investigations it is necessary to carry out a duplicate determination to get more accurate results.