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Uniformity of soil test results as influenced by volume weight
Titel:
Uniformity of soil test results as influenced by volume weight
Auteur:
Mehlich, A.
Verschenen in:
Communications in soil science and plant analysis
Paginering:
Jaargang 4 (1973) nr. 6 pagina's 475-486
Jaar:
1973
Inhoud:
Samples of four soils having a wide range of volume weights (0.65, 1.02, 1.25, 1.62 g/cm3) were either weighed or measured by volume and extracted with: (a) the Bray P1 extractant, (b) the Mehlich double acid extractant for P, K, Ca, Mg, Mn, Zn and (c) neutral N NH4OAc for K, Ca, Mg all at a soil/extracting solution ratio of 1:10. The soil test results were recorded on a volume basis in mg/dm3 and on a weight basis in mg/kg. The test values for all macronutrients obtained with all extractants decreased, relative to a constant volume, with increasing VW of soil when analyzed and expressed on a weight basis. Results based on the use of a volume sample (scooped) but calculated on an assumed weight of soil changed the values in direct ratio of 1/assumed VW. The use of an assumed VW has no justification, since uniform soil test results can be obtained when expressed on a volume basis by either using a scooped sample of known volume or a weighed sample followed by multiplication with the VW of each soil.
Uitgever:
Taylor & Francis
Bronbestand:
Elektronische Wetenschappelijke Tijdschriften
Details van artikel 179 van 183 gevonden artikelen
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