Climate change and soil C sequestration potential in

south-east Asia

K.R. Islam, Y. Raut, R. Shrestha, and R. Lal

State University

Several Arabian scientists (such as al-Razi, Ali b. Ridhwan, Ya‘qub al-Israili, and Ibn al-Nafis) dating back from 9th to 13th century addressed environmental pollution especially air and water contamination by human activities.

ttp://www.muslimheritage.com/

Squeezing earth for resources to emit C, N, and S based gases:

Carbon dioxide, methane, sulfur dioxide, nitrogen oxides, ammonia, smoke, etc.

http://www.worldviewofglobalwarming.org/

Loss of SOM as CO2

Total CO2 emissions ranking1/2 China/USA

4 India

34 Pakistan

67 Bangladesh

88 Sri Lanka

126 Nepal

162 Maldives

163 Afghanistan

175 Bhutan

(CDIAC 2008)

Per capita CO2 emissions (metric ton)1 Qatar 21.6

9 USA 5.6

109 Maldives 0.7

129 India 0.34

152 Pakistan 0.23

161 Sri-Lanka 0.16

175 Bangladesh 0.07

182 Bhutan 0.05

193 Nepal 0.03

205 Afghanistan 0.01

(CDIAC 2008)

Change in CO2 emission over time…_________________________________________Country 1972 2004 Change

_____ (M Mg) ______ (%)____________________________________________________________________________________________________________

Global 54999 98870 80Afghanistan 0.52 0.24 -54Bangladesh 1.16 12.7 995Bhutan 0.001 0.14 11200India 73.7 457.9 521Maldives 0.001 0.25 19500Nepal 0.09 0.10 14Pakistan 6.42 42.9 568Sri Lanka 1.17 3.93 235Total 83.1 518.1 524

(CDIAC 2008)

Global warming potentials___________________________________________Tropospheric Lifetime Global warmingGases (years) potential___________________________________________Carbon dioxide 50-200 1Methane 9-15 21Nitrous oxide 120 310CFC’s 1.5 - 264 140 - 11700___________________________________________

Fossil fuel emissions ~ 6.3 billion ton CO2/yrLand-use & deforestation ~ 1.9 billion ton CO2/yr

Evidence of climate change isundeniable

Climate change will affect every components and production system on earth

for Solutions

All the atmospheric CO2 ~ only 40% of the soil’s C holding capacity (Wallace 1984)

31.632.536.5Sri Lanka61.14.532.6Pakistan30.740.229.5Nepal70.03.326.7Maldives16.123.060.8India23.666.011.6Bhutan18.414.569.3Bangladesh39.12.658.3Afghanistan

__________(%)__________landsareaareaOtherForestedAgric.Country

Land use in South East Asia……

6.815.514.2Sri Lanka6.50.925.2Pakistan

12.10.916.5Nepal3.330.013.3Maldives3.73.154.0India8.80.42.3Bhutan4.63.461.3Bangladesh

46.00.212.1Afghanistan___________ (%) __________

landcropslandPasturePermanentArableCountry

Land use in South east Asia……

What to do?

•Increase in photosynthesis•Maximize water/nutrient use efficiency•Improve plant growth ~40%

~10 - 60%↑ in shoot production

~ 60 - 140%↑ in root production

Since plants are the primary receptors of CO2, any increase in [CO2] will have positive effects on plants:

Mulchi and Islam (2002)

No-Tillage +

Cover Crop

Re-aggregation

Cover + Crop roots

Continuous C flux

Active “Pool”Slow “Pool”Passive “Pool”

New Steady State

Continuous porosity

Natural Vegetation

Litter + roots

Active “Pool”Slow “Pool”Passive “Pool”

Continuous porosity

SteadyState

Aggregates

Forming

Continuous C flux

Conventional Tillage

Aeration + mix to Crop

Residue

Active MCB and high CO2 flux

Structure disrupted

InstableSOM Losses

Basic differences among land management systems

Conventional tillage to No-till: Bangladesh

In NT system, 30% residues left annually which is equivalent to 0.6 t/ha/yr. If crop residue decomposition is 0.25 then soil C content will be

> (0.6*0.75)*(58/100) -> 260 kg/ha/yr

If r (0.25) is the soil C that left in the 2nd yr after the decomposition of the soil C formed in the 1st yr, then the soil C sequestration after 10 yr will be

Y = soil C * (1 - rn)/(1 - r)

Y = 0.26*(1- 0.7510)/(1- 0.75) > 950 kg/ha

Land useWoodland Rangeland Farmland

C s

eque

stra

tion

(kg

ha-1

yr-

1 )

0

20

40

60

80

100

120

140

160

180

Afghanistan (Khan and Lal 2007)

Soil depth (cm)0-15 15-30 30-45 45-60

Tota

l C (M

g ha

-1)

0

5

10

15

20

25

30

Protected forest (2000) Initial (1982) Degraded forest (2000)

Natural forest Reforested Grassland Cultivated

Tota

l C (M

g ha

-1)

0

2

4

6

8

10

12

14

Bangladesh (Islam and Weil 2000)

Cropping systemsR-R M-W F-R-W Cassav

Tota

l C (M

g ha

-1)

0

2

4

6

8

10

12

14Initial ('75-78) Control ('95-98) NPK ('75-78) NPK+FM ('75-78)

Degraded soilsWater Wind Irrig Rainfed Saline

C s

eque

stra

tion

(kg

ha-1

yr-

1)

0

100

200

300

400

India(Lal 2004)

Management systemsReforested Initial 0-yr Cult. 50-yr

Tota

l C (M

g ha

-1)

0

5

10

15

20

0-15 cm 15-30 cm 30-60 cm

Hill- warm tempearte in Nepal

Management systemsUncult. 50-yr Initial 0-yr Cult. 50-yr

Tota

l C (M

g ha

-1)

0

2

4

6

8

10

12

14

0-15 cm 15-30 cm 30-60 cm

Terai- Sub-tropical in Nepal

Nepal(Maskey et al. 2000)

Time (year)0 2 4 6

Tota

l C (M

g ha

-1)

0

20

40

60

80

C sequestration = 9.3 Mg ha-1 y-1

N fertilization (kg ha-1)0 20 40 60 80 100C

seq

uest

ratio

n (k

g ha

-1 y

r-1 )

0

100

200

300

400

500

600

700

Farm manure Crop residue Mung bean

Pakistan(Khan and Lal 2005)

Afg

hani

stan

Ban

glad

esh

Bhu

tan

Indi

a

Mal

dive

s

Nep

al

Paki

stan

Sri L

anka

C s

eque

stra

tion

(kg

ha-1

yr-

1)

0

100

200

300

400

500

600

Lal 2004

Afg

hani

stan

Ban

glad

esh

Bhu

tan

Indi

a

Mal

dive

s

Nep

al

Paki

stan

Sri L

anka

Tota

l

Tota

l pot

entia

l (Tg

C)

0

5

10

15

20

Lal 2004

Recommended practices for soil C sequestration

Reduced tillage/Crop rotatione.g. No-till wheat

Organic amendmentse.g. Green manuringe.g. Biofertilizatione.g. Biosolids/composts/manures

Chemical fertilization/Liminge.g. NPK with micronutrients

Mulching/Residue Management

Agroforestry/Social forestry

Afforestation/Reforestation

Climate ChangeSong or Cry!

Who Cares?