Neutron radiography – Imaging roots in soil with
heterogeneous water and P distribution
B. Felderer1, P. Vontobel2, R. Schulin1
1Soil
Protection Group, Institute for Terrestrial Ecology, ETH, Zurich, Switzerland
2Spallation
Introduction
Neutron Source Division, Paul Scherrer Institute, Villigen, Switzerland
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
1
Introduction
 Water and nutrients are essential for plant growth
 Soil conditions and root growth determine water and nutrient
uptake
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
2
Spatial heterogeneity of soil
Vertical
Horizontal
http://commons.wikimedia.org
/wiki/File:Kuhflade.jpg
M. Altermann. J. Plant Nutr. Soil
Science 2005, 168, 725-740.
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
3
Root architecture differs between plant species
V. Dunbabin , Functional Ecology 2004, 18, 204-211
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
4
Root growth adapts to soil conditions
+ water
Low water supply
Introduction
Experiment 1
Experiment 2
High water supply
Experiment 3
Conclusion
Outlook
5
Root allocation in soil with heterogeneous P distribution
+ phosphorus
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
6
Root growth over time
 Developmental stage of a plant determines root allocation
 Seasonal changes of
water-distribution co-determine
root allocation
 …
M. Altermann. J. Plant Nutr. Soil
Science 2005, 168, 725-740.
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
7
Neutron radiography (NR):
Attenuation coefficients with neutrons [cm?¹]
1a
H
3.44
Li
3.30
Na
0.09
K
0.06
Rb
0.08
Cs
0.29
Fr
*Lanthanides
**Actinides
2a
Be
0.79
Mg
0.15
Ca
0.08
Sr
0.14
Ba
0.07
Ra
0.34
Ce
0.14
Th
0.59
3b
4b
5b
Sc
Ti
2.00 0.60
Y
Zr
0.27 0.29
La
Hf
0.52 4.99
Ac
Rf
V
0.72
Nb
0.40
Ta
1.49
Ha
Pr
Nd
0.41 1.87
Pa
U
8.46 0.82
Pm
5.72
Np
9.80
Legend
Neutron Attenuation
X-Ray
6b
7b
8
1b
2b
3a
Cr
0.54
Mo
0.52
W
1.47
Mn
1.21
Tc
1.76
Re
6.85
Fe
1.19
Ru
0.58
Os
2.24
B
101.60
Al
0.10
Co
Ni
Cu
Zn
Ga
3.92 2.05 1.07 0.35
0.49
Rh
Pd
Ag
Cd
In
10.88 0.78 4.04 115.11 7.58
Ir
Pt
Au
Hg
Tl
30.46 1.46 6.23 16.21 0.47
Sm
Eu
Gd
Tb
Dy
Ho
171.47 94.58 1479.04 0.93 32.42 2.25
Pu
Am
Cm
Bk
Cf
Es
50.20 2.86
Er
5.48
Fm
Tm
3.53
Md
4a
5a
6a
7a
C
0.56
Si
0.11
Ge
0.47
Sn
0.21
Pb
0.38
N
0.43
P
0.12
As
0.67
Sb
0.30
Bi
0.27
O
0.17
S
0.06
Se
0.73
Te
0.25
Po
F
0.20
Cl
1.33
Br
0.24
I
0.23
At
0
He
0.02
Ne
0.10
Ar
0.03
Kr
0.61
Xe
0.43
Rn
Yb
Lu
1.40 2.75
No
Lr
neut.
σ-total * sp.gr. * 0.6023
Attenuation coefficient [cm?¹] =
at.wt.
σ-total: JEF Report 14, TABLE OF SIMPLE INTEGRAL NEUTRON CROSS SECTION DATA FROM JEF-2.2, ENDF/B-VI, JENDL-3.2, BROND-2 AND CENDL-2,
AEN NEA, 1994.
and Special Feature: Neutron scattering lengths and cross sections, Varley F. Sears, AECL Research, Chalk River Laboratories Chalk River, Ontario, Canada KOJ
1JO, Neutron News, Vol. 3, 1992, http://www.ncnr.nist.gov/resources/n-lengths/list.html.
sp.gr.: Handbook of Chemistry and Physics, 56th Edition 1975-1976.
at.wt.: Handbook of Chemistry and Physics, 56th Edition 1975-1976.
Rees R, Environ Sci Technol 2011; 45: 10538-10543.
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
8
Exp 1: Which plant species?
FOV= 18*18 cm, pixelsize= 180 µm
• Plant species:
• Lupinus albus (Lupin)
• Pisum sativum (Pea)
• Cicer arietinum (Chickpea)
• Lens culinaris (Lentices)
 Growth period: 56 days
 Root length measurement
after…
• NR
• Root washing
27 cm
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
9
Root Imaging
Roottracker –
software
developed by A.
Kästner (PSI)
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
10
WinrhizoPro® for root analysis
 Root length
 Root diameter

Introduction
Experiment 1
Experiment 2
Experiment 3
…
Conclusion
Outlook
11
Recovery of root length
Introduction
Root length measured in NR
=
Root length measured after root washing
Lupin: 90% (±4)
Pea: 60 % (±9)
Chickpea: 65 % (±5)
Lentices: 55 % (±9)
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
12
Root growth of lupin
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
13
Cluster roots in white lupin
 Densely packed rootlets
 Increased organic
acid exudation
 Increased solubilization of P
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
14
Exp 2: Root allocation in soil with heterogeneous water
and P distribution
Increased water
Increased P
availability
concetration
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
15
Experimental design
3 (P-treatments)
x 2 (water distribution)
P fertilized soil
Introduction
Experiment 1
Experiment 2
Fine sand
Experiment 3
Conclusion
Outlook
16
Versuchsaufbau
+ H2O
Introduction
Experiment 1
+P
Experiment 2
Experiment 3
Conclusion
Outlook
17
Timing of root analysis
Neutron radiography
Day 12
Day 19
Day 35
Day 26
Germination
Root washing
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
18
Root analysis (root washing)
 Root length
 Cluster length
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
19
Root analysis (NR)
 Root length
 Cluster length
 Number of second order
laterals
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
20
cm
Root length (day 35)
Fine sand
P fertilized soil
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
21
cm
Cluster length (day 35)
Fine sand
P fertilized soil
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
22
Number of roots
Number of second order laterals (day 26)
Fine sand
P fertilized soil
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
23
Exp2: Summary
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
24
Exp 3 – Soil exchange at root tips
Apatit
10
0
40
6 replicates
Introduction
Experiment 1
Experiment 2
Experiment 3
100
mg P / kg soil
Conclusion
Outlook
25
Number of cluster roots build in the exchanged soil
0
Apatit
15
40
100
P had a stimulating effect on cluster root production at high supply rates
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
26
Conclusion: Neutronradiography (NR) benefits root
research
 Spatio - temporal root development
 Image processing and root analysis is very userfriendly
 High throughput
 Precise interventions at specific sites of the root system
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
27
Outlook
 BIOFORTIFICATION:
Zn-uptake and root architecture
Phd Student Huifang Ma, Soil Protection, ETHZ
 ROOT MODELLING:
NR images to parametrize a model
Daniel Leitner from (University Vienna), Andrea Schnepf (BOKU)
 SOIL FATIGUE IN APPLE TREES:
Effect of soil fatigue on root growth of different breedings
Introduction
Experiment 1
Experiment 2
Experiment 3
Conclusion
Outlook
28
Thank you for your attention!
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