Impacts of climate change on soil physical health

2. Climate change is the variation in either mean state of the climate or its
variables persisting for an extending period, typically decades or longer. It
encompasses temperature increase, sea level rise, changes in precipitation
pattern and increased frequencies of extreme weather events .

3.  Increasing in global average
air and ocean temperatures
 Rising global average sea
level
 Reductions of snow and ice
IPCC, 2007

4. Green house
gases (GHG)
Pre-industrial
concentrations
2008
concentrations
Human source GWP years
CO2 278 ppm 365 ppm
Now – 400 ppm
Fossil fuel, land use
change, combustion
1
CH4 700 ppb 1745 ppb Fossil fuel, rice culture,
livestock
24
N2O 270 ppb 314 ppb Fertilizer, fossil fuel
combustion
298
HFC 0 14 parts per trillion Liquid coolants 14800
CFC 0 80 ppt Refrigiration, electronic
industry
6500

5. CO2Concentration(ppm)
MethaneConcentration(ppb)
IPCC, 2007

6.  CO2 atmospheric concentration up from 280 ppm (pre-industrial) to 400ppm
(2013)
 GHG emissions up by 78% between 1970-2008
 Global mean temp. rise 0.74°C from 1906-2008
 Last 11 years (1995-2006), among the 12 warmest years since 1850
 Global sea level rise 1.8mm/yr during 1961-2005, faster during 1993-2003 (@3.1
mm/yr)

7. Climate change
Soil Processes
Human interventions
(landuse change, agrotechnologies,
management,….
Temperature, CO2,
rainfall
CO2, Methane, NO2,
Evaporation

8.  Soil physical properties provide information related to water and air movement through soil, as well as
conditions affecting germination, root growth and erosion processes.
 Form the foundation of other chemical and biological processes, which may be further governed by
climate, landscape position and land use.
Pattison, 2005

9. CO2
N deposition
Temperature
Rainfall
Increasing temperature
Altered precipitation
Increasing greenhouse gas
concentration
Warmer and shorter winters
Rising sea levels
Increased gene transfer rate
Virulent pathogens
Altered yieldsSoil processes
Porosity
Aggregate stability
Infiltration
Bulk density
Soil & rooting depths
Soil available water &
distribution
Soil surface cover
pH; rate of acidification or
alkanisation
Electrical conductivity; leachable
salts
Adsorption & cation exchange
capacity
Plant available N, P, K, S
Soil organic matter
Respiration
Soil biota biomass
Microbial biomass C & N
Potentially mineralizable N
Enzyme activity
Diane E. Allen., et al 2011

10. Soil Health
indicators
Soil process
affected
Determination Relevant to
climate change
Inclusion in Minimum
data set (MDS)
Reference
P
H
Y
S
I
C
A
L
Soil structure Aggregate
stability,
Organic matter
turnover
Surface seal,
chemical retention
Medium Frequent Idowu et al
(2009)
Porosity Air capacity,
AW, FC
Crusting, aeration,
water entry
High Frequent Kinyangi (2007)
Bulk density Structural
condition
Compaction Low Frequent Reynolds et al.
(2009)
Soil water FC, PWP,
macro pore
flow
Water and chemical
reaction
High Frequent Reynolds et al.
(2009)
Soil
protective
cover
Water and
nutrient
movement
C & N fixing
Physical strength Medium Frequent Kinyangi (2007)
Diane E. Allen., et al 2011

11. Soil Health
indicators
Soil process
affected
Determination Relevant to
climate change
Inclusion in MDS Reference
C
H
E
M
IC
A
L
pH Biological and
chemical activity
Structural stability,
salinisation.etc
Medium Frequent Haynes (2008)
EC Plant & microbial
activity
Leachable salts Medium Frequent Gregorich et al.
(1994)
N, P, K Available nutrients,
loss
Capacity for crop
growth, yield
Medium Frequent Reynolds et al.
(2009)
SOM Metabolic activity
of microbes, N flux
mineralization
Nutrient supply High Frequent Stenberg (1999)
Diane E. Allen., et al 2011

12. Soil Health indicators Soil process
affected
Determination Relevant to
climate change
Inclusion in
MDS
Reference
B
I
O
L
O
G
I
C
A
L
Soil C and N C:N ratio and
balance
Soil structure High Frequent Dalal &
Moloney
(2000)
Soil respiration Microbial activity Microbial activity High Some time Haynes (2008)
Microbial
quotient, enzyme
activity
Substrate use
efficiency,
Km. Q10
Nutrient supply High Some time -Do-
Microbial diversity Nutrient cycling, Biochemical quality High Some time -Do-
Diane E. Allen., et al 2011

13. Aggregate stability, the resistance of soil aggregates to external energy such as high intensity rainfall and
cultivation, is determined by
 Soil structure,
 Chemical and biological properties and
 Management practices.
(Dalal and Moloney 2000; Moebius et al. 2007).
Because of its association with the storage of soil organic carbon (SOC) and water, its measurement can be
useful to guide climate adaptation strategies.

14. Porosity, a measure of volume of voids to that of the total volume, and pore size distribution provide a direct,
quantitative estimate of the ability of a soil to store root-zone water and air necessary for plant growth
(Reynolds et al. 2002).
Elevated CO2 and temperature, and variable and extreme rainfall
events may alter
 Root development and soil biological activities,
 Soil porosity
 Pore size distribution and
 Consequently soil functions are likely to be affected in
unexpected directions

15. Soil water infiltration, the rate at which water enters the soil surface and moves through
soil depth
Since infiltration rate may change significantly with soil use, management and time, it has
been included as an indicator of soil health for assessments of land use change impacts
(Arias et al. 2005; O’Farrell et al. 2010)

16.  The availability of water for plant growth and important soil processes is governed by a range of soil
properties
 Porosity,
 Field capacity,
 Lower limit of plant available water and hence plant available water capacity,
 Macro pore flow and
 Texture.
 The soil available water and distribution may respond
rapidly to climate change, especially to variable and
high intensity rainfall or drought events.
(Jarvis 2007; Reynolds et al. 2002)

17. Components of the field water balance and soil moisture regime and the
influence of four potential climate scenarios on these factors: i and I: slight
and great increase; d and D: slight and strong decrease; E: no change
(equilibrium).
 Increases the potential E and T, if the plant canopy is not
suffering from limited water supply due to climate or soil
induced drought, e.g. Low precipitation or limited water
storage capacity;
 Decreases R, I, S and G, especially if accompanied by low
precipitation
Rise in temperature
Decrease in precipitation will result in a d
 Water infiltration (I) and water storage (S) in the soil; and
plants’ water supply
 Surface runoff (R) in hilly lands with undulating surfaces,
filtration losses and groundwater recharge (G)
Will increase
 Evaporation losses;
 The rate of transpiration (if the vegetation or crop canopy
has not deteriorated due to water deficiency)
Várallyay 2010

18.  Bulk density is a measure of a soils mass per unit volume of soil. It is used as a measure of soil wetness,
volumetric water content, and porosity.
 Bulk density is in general negatively correlated with soil organic matter (SOM) or SOC content.
(weil and Magdoff 2004)
 Elevated temperatures may lead to increase in bulk density and hence making soil more prone to
compaction via
 land management activities and
 Climate change stresses, for example, from variable and high intensity rainfall and drought events
(Birka´s et al. 2009).

19. • Changing rainfall patterns have the potential to change the
likelihood, extent and severity of sheet and rill erosion
• Erosion
• Desertification
• Nutrient and soil loss
USLE, Weismer and Smith (1978)
Soil Loss= R K L S C P
Rainfall intensity
Slope steep
Slope length
Land management
Crop
Soil Erodibility

20. Salinity and waterlogging are currently lowering the productivity of 25% of the world
cropland (Bowen & Young, 1990).
Preconditions for settlement of salts
• A salt source
• Water and wind erosion
• Negative water balance (PET > than rainfall )
• Limited drainage conditions
Climate change
induced

21. Study site: US Department of Agriculture Agricultural Research Service (USDA-ARS) High Plains Grasslands
Research Station, Wyoming, USA (41°11ˊN, 104°54ˊW).
Experimental design: Factorial
Treatments : ct, (ambient CO2 and ambient temperature); Ct, (elevated CO2 and ambient temperature); Ct
(ambient CO2 and elevated temperature); CT, (elevated CO2 and elevated temperature)

22. Soil cores from
each treatment
(0-15cm)
Labouratory
Portable ice box
Field moisture
content < 6% by
wt.
Seiving field moist
samples ( staking
sieves 1 and 0.25mm)
Manual
crumbling to <
8mm ( 3
minutes)
Picking up of
visible gravel
Large aggregates > 1mm
Macro aggregates 0.25-1mm
Micro aggregates
<1mm
Oven dry at
60°C
Determinig Wt.

23. Treatments Aggregate – Size Classes (mm)
>1 1-0.25 <0.25
ct 37.2±2.9 31.9±1.1 30.9±2.0
Ct 37.0±1.4 33.1±0.8 29.9±1.5
cT 33.1±3.2 33.7±1.2 33.2±2.1
CT 27.0±1.0 34.5±1.1 38.5±0.9
 Under ambient CO2 and temperature (control), weight distribution in the large macro aggregates was
significantly higher than two smaller aggregates.
 Compared to the control, Ct and cT treatments did not affect the weight distribution of aggregates.
 CT decreased weight distribution in the large macro aggregates.

24.  Compared to the control, CT significantly decreased water content except in microaggregates.
 Under Ct treatment, the highest water content was found in the large macroaggregates.
Bulk >1 mm 1-0.25 mm <0.25 mm

25. The study was undertaken in the Garhwal hills of Himalayan region with an estimated area of about 3571km2 (79°02ˊ11ˊ̋N
longitude, 30°03ˊ08ˊˊE latitude).
The agroecological sub-region map (Valayuthum et al., 1999) shows that the area is characterized by warm humid to per humid
(600–1200m a.s.l.) and warm to moist dry sub humid climate (1700–3000m a.s.l.).
The mean annual minimum temperature was 3°C at high altitudes in winter and reaches up to 30°C in valleys and piedmont
plains during summer

27.  The study area topography was delineated into four landforms, viz., hilltops, hillside slopes, valleys and piedmonts.
 They are further divided into 14 physiographic land units using landform analysis method based on slope gradient,
aspect, drainage, land use and other terrain features (Chopra and Sharma, 1993; Brabyn, 1997).
 Soil samples were collected from the physiographic units in 1978 and 2004 at the same sampling sites.
 Samples in 2004 were collected using the location map of samples prepared in 1978.
 The distance between the sampling points in 1978 and 2004 was minimized using Geographical Positioning System (GPS).

28.  Carbon storage was estimated in all the mapping units of different landforms considering the presence of
stones and gravel and bulk density to represent the real field conditions.
 Separate samples were collected simultaneously for BD estimation while soil sampling. Carbon storage was
estimated according to the method given by Batjes (1996).
SOC (Pg) = OC(g Cg -1 ) × BD(Mgm-3) × Horizon depth (m) ×Mapping unit area(M ha)

29.  Himalayan region in India is experiencing an
increase in mean annual temperature and a
decline in snowfall over the past few decades.
 The mean annual rainfall was reduced by 46 %
from 2292mm in 1955–1964 to 1239mm in
1982–2002.
 Mean monthly maximum (Tmax) and mean
monthly minimum (Tmin) shows that the mean
minimum air temperature and mean monthly
maximum temperatures have increased by 1.6
and 1.3 ◦C, respectively.
Soil organic carbon (0–1.5m) in benchmark site soils in different landforms
sampled between 1978 and 2004.

30.  The field study area was situated at an altitude between 1,880 and 2,030 m above sea level in the eastern
part of Turkey. This study was conducted in the laboratory and field during 2008-2009.
 The mean annual temperature, precipitation, evapotranspiration, and relative humidity for the region are
6.3-C, 398 mm, 1,060 mm, and 64%, respectively.

31.  Soil samples were taken over 0-cm to 10-cm depths to determine some chemical and physical properties. Soil
samples were air dried, crushed, and passed through a 2-mm sieve prior to chemical analysis.
 The percentage of wet aggregate stability (WAS) was then determined by a wet sieving procedure (Kemper and
Rosenau, 1986).
 The soil samples were then subjected to a freeze and thaw process from +20 to -30°C to simulate field condition.
 Pellustert, Argiustoll, Haplustept, and Fluvaquent, in the freezing- and thawing-treated cycles (FTTC) study in the
laboratory.
 Sufficient deionized water was added to each sample to produce a soil at either 15% or 26% gravimetric moisture
content.

32.  The long-term (60 years) air temperature
average has been reported to be -10°C, -15°C,
and -20°C for December, January, and February,
respectively; the actual average air temperature
range was 0°C to 10°C (+2.5°C, +5°C, + 7.5°C, and
+10°C).
 The average sunny hours and thawing hours per
day were 18 and 6 h for March, April, and May,
respectively.

33.  Field experiment study was conducted in 2008 to 2009 in the Pellustert, Argiustoll, Haplustept, and
Fluvaquent major soil groups. Individual plots were 1.5 ×4m2
 The available moisture content of soil was 105.3 mm m-1. All plots were irrigated, soil moisture contents
in all plots were increased to the field capacity at the beginning of periods.
 Soil sampling was taken from 0 to 10 cm every 15 days, and soil moisture and temperature were
measured

36.  The initial WAS of the untretated freeze-thaw cycles (UT) was the highest in Argiustoll and Pellustert soil, followed by
Haplustept and Fluvaquent
 The highest WAS values of all the soils studied under laboratory conditions were observed with soils frozen at -10°C for
30 days, -15°C for 30 days, and -20°C for 30 days; subjected to refreezing at -10°C for 15 days,-5°C for 15 days, and 0°C
for 15 days; and then thawed at +10°C in 18 h and 6 FTTC at Argiustoll soil followed by Pellustert > Haplustept >
Fluvaquent
 In the field, the study results showed
that the WAS values exhibited a similar
trend to Step 1 in the laboratory results

37.  The field based on the climate change occurring over the last decade showed that freeze-thaw temperature is getting
higher and that the WAS of soil was lower under the field conditions than occurred in the laboratory experiment.
 Accordingly, the WAS of soil during the global climate change period is reduced after 3 or 6 FTTC, but is increased after
9 FTTC at present or in the future.
 If the global climate changes continue on this trend, the WAS of soils will decrease. Especially, the Fluvaquent major
soil group will be deeply affected by this trend followed by Haplustept and Pellustert in the future.
Based on these results, the study emphasize that highland soils are most sensitive to the global climatic change.
Increasing air temperature has resulted in a rise in soil temperature and an increasing frequency of soil freeze-thaw cycles
during the winter in cool-temperature and other high-latitude regions.

38.  Climate change broadly affect the soil health via; changing the physical, chemical and
biological properties of soil.
 Warming climate is major threat to soil health by decreasing of SOM. Elevated
temperature reduce productivity, enhance soil respiration, and soil CO2 efflux.
 Soil water availability and porosity (highly impacted by climate change) and bulk density
(less impacted by climate change).
 Among the soil properties, SOM is a very sensitive indicator which highly degraded by
changing climate.

39.  Give more emphasis on sensor based system for monitoring of soil health.
 Modelling should be done to all ecological zones for predict the conditions of soil health.