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Retention, hydrolysis and plant availability of pyrophosphate applied to organic soil material

Pyrophosphate retention and half-life values, and pyrophosphatase activity, were determined in 24 organic soil materials containing < 20% ash. Pyrophosphate retention was correlated with ash content (r = 0,876**) but still was weak. Pyrophosphatase activity (11,6 to 148,1 mmol.kg('-1).2h('-1)) was higher in virgin than in cultivated materials and was promoted apparently by nonspecific acid phosphatases. The interaction between water-soluble pyrophosphate and pyrophosphatase activity explained 77% of the variation in log-transformed half-life values ranging from 0,1 to 3,7 days. Copper decreased significantly pyrophosphatase activity. However, pyrophosphate hydrolysis rate was not affected significantly by Cu contents up to 1177 mg.kg('-1) in humic materials. Because of rapid rates of pyrophosphate hydrolysis in humic and mesic materials compared with rate of P uptake by onions, no significant difference in bulb yield and P uptake were obtained at harvest between pyrophosphate and orthophosphate fertilizers.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.71937
Date January 1984
CreatorsParent, Léon-Etienne.
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageDoctor of Philosophy (Department of Renewable Resources.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 000196960, proquestno: AAINK66681, Theses scanned by UMI/ProQuest.

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