Crop water productivity: briefing on concepts, definitions and goals, Andrew Noble

Andrew Noble Deputy Director General-Research

NENA REGIONAL STAKEHOLDERS WORKSHOP

27-29 Oct 2015, Cairo, Egypt

Remote Sensing: A transformative technology: • Multi-sensor and multi-scale observations

of carbon (biomass, yield); • Water productivity (WUE, WPM), water

accounting • Surface energy fluxes (G×E, stress)

Scale pixel to landscape Productivity of Croplands, Grasslands; Livestock and Trees Based

Systems; Quantification of Traits/Integrated Breeding; Land Degradation and Desertification; Extreme Events, Climate Change and

Resilience

Integrated Earth Observation System

Water Productivity

Net/Gross Return WP = Unit of water consumed

Biomass, grain, meat/milk (kg) Income ($) Environmental benefits (C) Social benefits (employment) Energy (Cal) Nutrition (protein, carbs, fat)

Evaporation Transpiration Quality

/pixel)mor /m(m ETor useWater

($) valueeconomicor kg/pixel)or (kg/m Yield )(kg/m WP

323

actual

23

Concept and Methods

Return: Yield, Biomass, GPP: RS and Insitu Observation using Biophysical/Biospectral, and VPM models

Scale Matters

Assuming 25 units of surface + subsurface losses

ET components from ETMonitor

E/ET(%), 2010

Ic/ET(%), 2010 T/ET(%), 2010

Total ET(mm/yr), 2010

Plant transpiration dominants in vegetation covered area

Soil evaporation contributes to total ET most in arid and semi – arid areas

Canopy interception losses contribute to total ET most in low latitude forest areas

Source: Wim Bastiaanssen

Water Productivity Score – Continental Wheat

Source: Wim Bastiaanssen

WP of Cotton 0.42 kg/m3 0.50 USD/m3

WP of Wheat 0.60 kg/m3 0.33 USD/m3

WP of Rice paddy 0.50 kg/m3 0.10 USD/m3

Water productivity (WP) is defined as the kg of yield produced/m3 of water used or, alternatively, as value in $ of yield produced/m3 of water used.

Good Farm boundaries for better interventions Land and Water Productivity Pixels to Fields

(Biradar et al., 2009)

Looking

East

Looking

South

Looking

West

Looking

North

Field West

North

East

Down

South

Ground Truth Data and Validation: Open Data Kits, Citizen Science/Community RS

Irrigation Development & ET

• 18-year ET estimates from AVHRR indicate persistent increase in ET.

• Increasing trend on average is 4.9 mm/year

y = 4.9x + 581

400

450

500

550

600

650

700

750

800

19

83

-84

19

84

-85

19

85

-86

19

86

-87

19

87

-88

19

88

-89

19

89

-90

19

90

-91

19

91

-92

19

92

-93

19

93

-94

19

94

-95

19

95

-96

19

96

-97

19

97

-98

19

98

-99

19

99

-00

20

00

-01

ET (

mm

/yea

r)

Year

Krishna River Basin-Annual ET

Annual ET Linear (Annual ET)

Source: Teluguntla et al. 2013 ACIAR Krishna Basin Project

Irrigation Development & ET

• The increasing trend is driven by the increase in ET during the dry (Rabi) season.

• This trend is because of irrigation development.

0

10

20

30

40

50

60

70

80

90

Jul-

83

Feb

-84

Sep

-84

Ap

r-8

5

No

v-8

5

Jun

-86

Jan

-87

Au

g-8

7

Mar

-88

Oct

-88

May

-89

De

c-8

9

Jul-

90

Feb

-91

Sep

-91

Ap

r-9

2

No

v-9

2

Jun

-93

Jan

-94

Au

g-9

4

Mar

-95

Oct

-95

May

-96

De

c-9

6

Jul-

97

Feb

-98

Sep

-98

Ap

r-9

9

No

v-9

9

Jun

-00

Jan

-01

Au

g-0

1

ET (

mm

/ m

on

th)

Months

AVHRR-8km ET

AVHRR-8km ET

Source: Teluguntla et al. 2013 ACIAR Krishna Basin Project

Productivity Land degradation Landuse dynamics Yield gaps Droughts/Floods CC and Impact

Mapping and Monitoring Major ALS

Scaling Similarity Prioritization Contexts Ex-ante

Farmscape to Landscapes

#/km2

(Biradar & Xiao, 2010, 2013)

Changing Cropping Systems • Cropping Intensity & Pattern • Land use/land cover change • Dynamics of Crop Fallows • Conservation Agriculture • Climate Change Impact • Input Use Efficiency

Agricultural Intensification

Cropping Intensity

Increase in Arable Land

72%

21% 7%

Land Use Map 2004/05

Irrigation Induced Salinity Control and Reclamation Project

Impact assessment and Ex-ante Analysis Change in Space and Time

Conclusions

• Water Productivity (WP) is an integrating element that goes beyond a simple ratio.

• Scale matters

• Transpiration is fixed – unless we change the physiological attributes of crops.

• E in ET is where gains can be made through management.