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Soil Use and Management - 2022 - Touhami - Effects of long‐term phosphorus fertilizer inputs and seasonal conditions on.pdf (998.83 kB)

Effects of long-term phosphorus fertilizer inputs and seasonal conditions on organic soil phosphorus cycling under grazed pasture

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posted on 2023-05-03, 22:00 authored by Driss Touhami, Leo Condron, Richard McDowell, Ray MossRay Moss
Soil microbes and phosphatase enzymes play a critical role in organic soil phosphorus (P) cycling. However, how long-term P inputs influence microbial P transformations and phosphatase enzyme activity under grazed pastures remains unclear. We collected top-soil (0–75 mm) from a grazed pasture receiving contrasting P inputs (control, 188 kg ha−1 year−1 of single super phosphate [SSP], and 376 kg ha−1 year−1 of SSP) for more than 65 years. Olsen P, microbial biomass P, and acid and alkaline phosphatase enzyme activities were measured regularly over a 2-year period. Pasture dry matter and soil chemical properties were also investigated. Results showed that long-term P inputs significantly increased pasture dry matter, total N, and the concentrations of –N but significantly decreased soil pH and the concentrations of –N. Total C was not affected by P fertilization. Although Olsen P significantly increased with increasing long-term P inputs, microbial biomass P was similar under P fertilized treatments. Long-term P inputs decreased acid phosphatase activity but increased alkaline phosphatase activity. Microbial biomass P was similar across seasons in the control but decreased in spring and autumn while increased in summer and winter under P fertilized treatments. Acid and alkaline phosphatase activities were significantly affected by season and followed similar seasonal trends being maximum in summer and minimum in winter regardless of P treatment. Correlation and principal component analysis revealed that acid and alkaline phosphatase activities were significantly positively correlated with soil temperature and significantly negatively correlated with soil moisture. In contrast, Olsen P and microbial biomass P were weakly correlated with environmental conditions. The findings of this study highlight the intertwined relationship between organic P cycling and the availability of C and N in soil systems and the need to integrate both soil moisture and temperature in models predicting organic P mineralization, especially in the context of global climate change.

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Rights statement

© 2022 The Authors. Soil Use and Management published by John Wiley & Sons Ltd on behalf of British Society of Soil Science.||This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Language

  • English

Does this contain Māori information or data?

  • No

Publisher

Wiley

Journal title

Soil Use and Management

ISSN

0266-0032

Citation

Touhami, D., Condron, L. M., McDowell, R. W., & Moss, R. (2023). Effects of long-term phosphorus fertilizer inputs and seasonal conditions on organic soil phosphorus cycling under grazed pasture. Soil Use and Management, 39(1), 385-401. https://doi.org/10.1111/sum.12830