Een onderzoek naar fijnheid en verdeeling van het phosphorzuur en zijn opneembaarheid in de mergelgronden van Java

J.T. White

Research output: Thesisinternal PhD, WU

Abstract

In 1907 it had been established by Marr and Geerts, that margalitic soils with a content of less than 0.03 % P205 soluble in cold 25 % HC1 or 0.01 % soluble in 2 % citric acid were P deficient. An attempt was therefore made to explain why some soils with P well above this limit responded to superphosphate.

Assuming that the availability of Ca3(PO4)2 depended on its specific surface area, fractions by size were isolated from the soils by Mohr's method of mechanical analysis, and P was estimated in the fractions. P content of the sand fraction was high and decreased with decreasing particle size to a value below the established limits. This contrasted with the rule for soils in temperate climates. Neubauer tests showed that P in the clay fractions was 100 % available, but that of the silt and sand fractions only for 30 %. The distribution of P over the size fractions was especially unfavourable for the margalites rich in P and explained their favourable reaction to P fertilizer.

Original languageDutch
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Aberson, J.H., Promotor, External person
Award date16 Dec 1926
Place of PublicationWageningen
Publisher
Publication statusPublished - 1926
Externally publishedYes

Keywords

  • soil
  • phosphoric acid
  • calcareous soils
  • clay soils
  • marl soils
  • java
  • indonesia
  • netherlands east indies

Cite this