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Climatic Effects on Phosphorus Fractions of Native and Cultivated North American Grassland Soils
Author(s) -
Siebers Nina,
Sumann Matthias,
Kaiser Klaus,
Amelung Wulf
Publication year - 2017
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2016.06.0181
Subject(s) - arable land , soil water , precipitation , grassland , phosphorus , environmental science , transect , agronomy , chemistry , soil science , agriculture , ecology , geography , biology , organic chemistry , meteorology
Core Ideas Influence of climate on phosphorus dynamics in soil. Regression analyses for climosequence in Great Plains. Influence of cultivation and size fractions on phosphorus dynamics. The climatic regime influences the turnover of P in soils, resulting in shifts in P fractions of different bonding forms. Here, we aimed at (i) identifying possible changes in P fractions as related to mean annual temperature (MAT) and mean annual precipitation (MAP), as well as (ii) elucidating how these patterns change under long‐term agriculture. We analyzed different P fractions after sequential extraction according to the Hedley procedure from the top 10 cm of 18 native grassland sites and adjacent long‐term agricultural fields along a temperature and precipitation transect from central Saskatoon to south Texas. The analyses were performed on bulk soils and clay fractions. The results showed that total P (P tot ) concentrations decreased with increasing MAT but were not clearly related to MAP. The contributions of total inorganic P (Pi tot ) and total organic P (Po tot ) to P tot did neither change with MAT nor with MAP. The proportions of individual soil fractions were shifted from the labile and easily extractable P bonding forms to the more stable, residual P fractions with increasing annual temperature. Arable cropping induced loss of organic P (Po). The relationships to the climatic factors were sustained for the arable soil, but better reflected in the clay fractions than in the bulk soil. We conclude that there is a gross pattern of soil P distribution related to the climate, likely reflecting the increased biological processing as well as and progressing weathering and neoformation of secondary mineral phases as annual temperatures rise.