Significance of Root-Attached Soil and Soil Preparation for Microbial Biomass Phosphorus Measurement
- M.S.A. Blackwell *a,
- J.K. Williamsa,
- K.E. Snarsb,
- P.C. Brookesb,
- N. de la Fuente-Martineza,
- L. Michallonb,
- P.J. Murraya and
- P.M. Haygarthac
- a Cross Institute Programme for Sustainable Soil Function, North Wyke Research, Okehampton, Devon, EX20 2SB, UK
b Cross Institute Programme for Sustainable Soil Function, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
c Currently at, Centre for Sustainable Water Management, Lancaster Environment Centre, Lancaster Univ., Lancaster, LA1 4YQ, UK
The preparation of soil for measurement of properties such as microbial biomass P involves the removal of plant roots. Any soil attached to the roots (root-attached soil) is also removed. In a very poorly drained silty clay loam under grassland we found that the root-attached soil contained more than twice the quantity of bicarbonate extractable P than the bulk soil. Discarding this root-attached soil could potentially result in underestimation of bicarbonate extractable P. We also showed that preferential inclusion of deeper soil due to variability of root density with depth is likely to result in underestimation of soil bicarbonate extractable P in fumigated and unfumigated soil samples. Additionally we investigated a conventional and alternative (rapid) soil preparation technique that might affect the accuracy of measurement of soil bicarbonate extractable P as part of a microbial biomass P measurement. Preparation technique made no significant difference to the quantity of P recovered.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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