Nucleic acids are a major pool of hydrolyzable organic phosphorus in arable organic soils of Southern Ontario, Canada

Autor: Christian von Sperber, Chandra A. Madramootoo, Aidan De Sena, Joann K. Whalen
Rok vydání: 2021
Předmět:
Zdroj: Biology and Fertility of Soils. 58:7-16
ISSN: 1432-0789
0178-2762
Popis: Soil organic phosphorus (Po) that is hydrolyzed by phosphatases into inorganic phosphate is a source of phosphorus (P) for agricultural crops. However, the hydrolysis of Po compounds is contingent on their chemical form and stabilization in the soil matrix. We quantified three hydrolyzable Po pools (simple phosphomonoesters, phospholipids, and nucleic acids) by adding substrate-specific phosphatases to Hedley sequentially fractionated extracts from three organic soils cultivated with carrots in Southern Ontario, Canada. We observed that most of the molybdate-unreactive P was hydrolyzable in the deionized water, 0.5 mol L−1 NaHCO3, and 0.1 mol L−1 NaOH P pools (67–92%) and accounted for 14–254 kg P ha−1 in these arable organic soils. Nucleic acids represented 79% of the hydrolyzable Po in these soils but were mostly found in the 0.1 mol L−1 NaOH P pool (89%), suggesting that this Po form is bound to the soil matrix, probably to organic complexes based on the strong association between nucleic acids and total organic C (ρ = 0.805). Therefore, we propose that nucleic acids are a major hydrolyzable Po pool that are stabilized by the organic C contained in the organic soils of this study. This Po compound class should be considered in the Po biogeochemical cycle of these soils.
Databáze: OpenAIRE
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