sustainable nutrient cycling through soil biota health 2016... · benefits soil organisms can...
TRANSCRIPT
Sustainable nutrient cycling through soil biota
S. Franz BenderScow Soil Microbial Ecology Lab
Dept. of Land, Air & Water Resources
Soil- a black box
Fotos: Bardgett and van der Putten, 2014, Nature;http://copalindia.blogspot.ch/2013/11/indigenous-soil-management-cost.htm;http://www.eurekalert.org/multimedia/pub/47157.phpl
Soil life1g of soil contains: 109 bacteria, 6’000 – 50’000 bacterial species and up to 200m fungal
hyphae
Roesch et al., ISME Journal 2007
Benefits soil organisms can provide
Organic matter decomposition
Carbon sequestration
Soil structure, soil porosity
Water infiltration
Pest control
Nutrient storage
Nutrient release
Breaking down toxic compounds
http://landscapeforlife.org/soil/support-the-soil-food-web/
Intensive agriculture
ecosystem simplification, reduced niche diversity
reduced biodiversityabove-and belowground
• Monoculture• Intensive soil tillage• high fertilization rates• Pesticides
Tsiafouli et al. 2015, Global Change Biology
Fertilization high yield decreasing nutrient use efficiency
agricultural resource use
Tilman et al. 2002, Nature
Nitrogen (N) and Phosphorus (P) limit plant growth worldwide
globally, about 50% of N fertilizers applied remain unused by crops
Nutrient leaching
greenhouse gas emissions
NN
N NN
N
N NN
Liu et al. 2010, PNAS
extensive system
Low external inputs
high above- andbelowground
diversity
Low productivity
- Low nutrientavailability
- High rate ofinternal nutrient cycling
- Low nurient losses
High sustainability
intensive system
high externalinputs
low above- andbelowground
diversity
high productivity
- high nutrientavailability
- low rate of- internal
nutrient cycling
- high nurient losses
Low sustainability
sustainable system
moderate externalinputs
moderate above-and belowground
diversity
high productivity
- high nutrientavailability
- High rate ofinternal nutrient cycling
- Low nurient losses
High sustainability
Can we manage soils to enhance agricultural sustainability?
Bender et al. 2016, Trends in Ecology and Evolution
1. Which role do soil organisms play in nutrient cycling and ecosystem sustainability?
2.How can this knowledge be applied to enhance the sustainability of cropping systems?
Research Questions
Other services• Soil structure• Seedling establishment• Drought resistance• Pathogen resistance• Reduce nutrient leaching
Arbuscular mycorrhizal fungi (AMF)
Symbiotic relationships with about 80% of all land plants
Extend plant-root systemEnhance nutrient uptake from soil
Improve plant growth and nutrition
Foto: Giovannetti et al. 2001, New Phytologist
Grafik: Sari Timonen
Grafik: Sari Timonen
Mykologie 2015
Grafik: Sari Timonen
AMF effects vary with soil conditions
Can AMF reduce nutrient losses from soil?TDP
mg
/kg
so
il
0.0
0.5
1.0
1.5
2.0
MNM
TDP
mg
/kg
so
il
0.0
0.5
1.0
1.5
2.0
MNM
Bender et al. 2014, Soil Biology & Biochemistry
TDP
mg
0.0
0.1
0.2
0.3
0.4
Tota
l P [
mg]
P leaching
bio
mas
s [g
]
total biomass
g
0
10
20
30
40
NH4 NO3 NH4 NO3
pasture heath
Plant biomass
NH4 NO3 NH4 NO3
pasture heath
Do AMF affect N2O emissions from denitrification?
Grass experiment:Sterilized and
re-inoculated
sand-soil mixWithout AMF
(NM)
With AMF
(M)
Mutant (NM)
reduced AMF
colonization
Wildtype(M)
colonized by
AMF
Tomato experiment:Fresh field soil + AMF inoculum
AMF reduce N2O emissions
Bender et al. 2014, ISME Journal
Without AMF:
34% increase
Without AMF:
42% increase
Tillage practices affect ecosystem services and plant productivity by changing arbuscular mycorrhizal fungal communities
Luise Olbrecht | © Agroscope Reckenholz-Tänikon Research Station ART, Switzerland
Trap cultures
Do AMF communities from tilled and non-tilled soils have different functional properties?
No AMF
Plants:Lolium multiflorumPlantago lanceolataTrifolium pratense
No-till Till
Replicates x 8
Tillage practices affect ecosystem services and plant productivity by changing arbuscular mycorrhizal fungal communities Luise Olbrecht | © Agroscope Reckenholz-Tänikon Research Station ART, Switzerland
No till communities form more fungal hyphae in soil
Tillage practices affect ecosystem services and plant productivity by changing arbuscular mycorrhizal fungal communities
Luise Olbrecht | © Agroscope Reckenholz-Tänikon Research Station ART, Switzerland
b
b
a
Köhl et al. 2014, Ecological Applications
Tillage practices affect ecosystem services and plant productivity by changing arbuscular mycorrhizal fungal communities
Luise Olbrecht | © Agroscope Reckenholz-Tänikon Research Station ART, Switzerland
c
a
b
Köhl et al. 2014, Ecological Applications
No-till communities strongly enhance plant P contents
Field inoculation with AMF+ Pseudomonads+ entomopathogenic nematodes
Improved resistance against pathogen attack (frit fly larvae)
Inoculated AMF can successfully compete with native AMF communities
Schlaeppi et al. 2016, New Phytologist
• 7m3 / 9 tons of sterilized soil (sub- and topsoil)
• Sterilized with x-ray irradiation
Bender and Van der Heijden, Journal of Applied Ecology 2015
Can soil organisms enhance nutrient use efficiency in agricultural systems?
2 Treatments
enriched soil life organisms <2mm (including AMF)
reduced soil life Control inoculum organisms <11
µm (no AMF)
8 replicates
Leachate collectionPlant biomassSoil data
crop rotation(2 years):
Corn,Wheat, Grass-clover
Bender and Van der Heijden, Journal of Applied Ecology 2015
Can soil organisms enhance nutrient use efficiency in agricultural systems?
Enhanced plant nutrient uptake
ENR: ‘enriched soil-life’RED: ‘reduced soil-life’
yield N-uptake P-uptake
Can soil organisms enhance nutrient use efficiency in agricultural systems?
Bender and Van der Heijden, Journal of Applied Ecology 2015
Enhanced corn yield and nutrient contents
reduced nutrient losses
N-leaching N2O-emissions N2-emissionsENR: ‘enriched soil-life’RED: ‘reduced soil-life’
Can soil organisms enhance nutrient use efficiency in agricultural systems?
Soil organisms possess great potential to enhance the nutrient use efficiency of cropping systems
Soil biodiversity and ecosystem multifunctionality
Inocula size in μm:
Functional Guild Size
0 (sterile)< 10 < 25< 50 < 250 < 50001 2 3 4 5 6
0.0
0.2
0.4
0.6
0.8
1.0
Soil community
x2
RY
Mycorrhiza
Fungi
Bacteria
Nematodes
Soil DNA
Mycorrhiza
Fungi
Bacteria
Nematodes
Soil DNA
Re
lative
ch
an
ge
in
so
il
co
mm
unity c
hara
cte
ristic
Soil biodiversity loss...
reduces nutrient cycling and decomposition
increases nutrient losses
1 2 3 4 5 6
0
1
2
3
4
5
6
7
Nutrients lossed
N leaching
P leaching
N2O emission
N leaching
P leaching
N2O emission
1 2 3 4 5 6
0.5
0.6
0.7
0.8
0.9
1.0
1.1
Soil processes
N turnover
Decomposition
C sequestration
N turnover
Decomposition
C sequestration
Re
lative
Ch
an
ge
in
Eco
syste
m F
un
ctio
n
5000 250 50 25 10 0Filter size (μm)
decreasing soil biodiversityWagg et al. 2014, PNAS
Soil biodiversity enhances ecosystem multifunctionality
-1.5 -0.5 0.0 0.5 1.0 1.5
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
R2=0.56, F(1,73)=62.9, P=0
Wagg et al. 2014, PNASSoil biodiversity (z score)
Multifun
ction
alit
y (
z s
core
)
R2 = 0.56
P < 0.001
-1.0
Summary
• AMF can reduce nutrient leaching and enhance plant nutrition depending on environmental conditions
• AMF can reduce N2O emissions from soil
• Soil biota have great potential to enhance the nutrient use efficiency of cropping systems
• Soil biodiversity supports several ecosystem functions simultaneously (multifunctionality)
Reducing management intensity and actively promoting soil biological communities might be a strategy to increase the nutrient use efficiency and
sustainability of cropping systems
OutlookLand-use intensity, soil biodiversity and ecosystem multifunctionality in Northern
Californian ecosystems
grasslandcrop rotations Fumigated monocultures
Ecosystem functioning? Nutrient cycling processes?
Field soils
Field soils, but soil organisms killed
Differences in ecosystem functioning?
In the greenhouse
Land-use intensity, soil biodiversity and ecosystem multifunctionality in Northern Californian ecosystems
Soil organisms matter for the for self-maintaining capabilities of soils
ThanksUC Davis, Dept. Of Land, Air and Water Resources
Kate Scow and the Soil Microbial Ecology lab
Jorge Rodrigues
Plant-Soil-Interactions, Institute of Sustainability Sciences
Marcel Van der Heijden, Raphael Wittwer, Werner Jossi, Luise Köhl, Cameron Wagg,
Caroline Scherrer, Kyle Hartman, Janine Moll, Florian Walder, Klaus Schlaeppi, Sarah
Pelkofer, Verena Sähle, Fritz Oehl, Beatriz Estrada, Alain Held, Julia Hess
AFBI, Belfast, UK
Ronnie Laughlin, Rachael Carolan,
Catherine Watson
Helmholtz Centre Munich
Michael Schloter, Stefanie Schulz
The James Hutton Institute, Dundee, UK
Tim Daniell
ECT Ökotoxikologie GmbH, Flörsheim, D
Jörg Römbke , Bernhard Förster
Thank You!