Pedosphere 25(5): 770--780, 2015
ISSN 1002-0160/CN 32-1315/P
©2015 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil microbial responses to biochars varying in particle size, surface and pore properties |
N. M. JAAFAR1,3 , P. L. CLODE2 and L. K.
ABBOTT1 |
1Soil Biology and Molecular Ecology Group, School of
Earth and Environment (M087) and UWA Institute of
Agriculture, The
University of Western Australia, Crawley
6009 (Australia)
2Centre for Microscopy, Characterisation and Analysis
(M010), The University of Western Australia, Crawley 6009
(Australia)
3Department of Land Management, Faculty of
Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang,
Selangor (Malaysia) |
| ABSTRACT |
| Biochars are known for their heterogeneity, especially in
pore and surface structure associated with pyrolysis
processes and sources of feedstocks. The surface area of
biochar is likely to be an important determinant of the
extent of soil microbial attachment, whereas the porous
structure of biochar is expected to provide protection for
soil microorganisms. Potential interactions between
biochars from different sources and with different particle
sizes were investigated in relation to soil microbial
properties in a short-term incubation study. Three particle
size (sieved) fractions (0.5--1.0, 1.0--2.0 and 2.0--4.0
mm) from three woody biochars produced from jarrah wood,
jarrah and wandoo wood and Australian wattle branches,
respectively, were incubated in soil at 25 oC for 56
d. Observation by scanning electron microscopy (SEM) and
characterisation of pore and surface area showed that all
three woody biochars provided potential habitats for soil
microorganisms due to their high porosity and surface
areas. The biochars were structurally heterogeneous,
varying in porosity and surface structure both within and
between the biochar sources. After the 56-d incubation,
hyphal colonisation was observed on biochar surfaces and in
larger biochar pores. Soil clumping occurred on biochar
particles, cementing and covering exposed biochar pores.
This may have altered surface area and pore availability
for microbial colonisation. Transient changes in soil
microbial biomass, without a consistent trend, were
observed among biochars during the 56-d incubation. |
| Key Words: microbial biomass, microbial colonisation, microbial
habitats, porosity, scanning electron microscopy,
surface structure |
| Citation: Jaafar, N. M., Clode, P. L. and Abbott, L. K. 2015. Soil microbial responses to biochars varying in particle size, surface and pore properties. Pedosphere. 25(5): 770-780. |
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