Water Productivity in Agriculture
Sharad K. Jain and Pushpendra K. Singh - Scientists
Water Resources Systems Division,
National Institute of Hydrology Roorkee, Uttarakhand 247667
2. WATER and LAND: The prime natural drivers
The most essential components of natural resources
system: availability and accessibility have played a key role
in determining the locations of cities, towns, and villages
around the world.
The world will face a 40% water gap for covering the global
drinking water, energy and food needs by 2030. Land and
water scarcity will play a major constraint for ensuring foodwater scarcity will play a major constraint for ensuring food
security for ever-growing population.
3. land use land cover change;
Urbanization and
industrialization ;
engineering schemes likeg g
reservoirs, irrigation;
inter‐basin transfers (that
maximize human access to
F(X)
water) transform the
natural water systems to a
great extent; andgreat extent; and
Hydropower generation
4. U i d N i ( ) United Nations (2001):
transition from a rural, agrarian society to an urban
and industrial one and by 2050
abo t 70% of the global pop lation ill inhabit rban about 70% of the global population will inhabit urban
areas, up from about half today
Almost all of this increase in urban
population will occur in the developing worldpopulation will occur in the developing world
and more than half of the growth will occur in
just two countries, India and China (Cohen,
2004)2004).
5. Inter Governmental Panel on Climate Change (IPCC AR5Inter‐Governmental Panel on Climate Change (IPCC‐AR5,
2014) says:
1. between 1906‐2005: earth temperature has increased by 0.740C
due to increase in anthropogenic emissions of greenhouse
gases;
2. by the end of this century the temperature increase is likely to
be 1.8‐4.00C.
This would lead to more frequent hot extremes, floods,
droughts, cyclones and gradual recession of glaciers, which
in turn would result in greater instability in food production.
P l (2013)
For each degree of global mean temperature rise,
an additional 4% of the global land area is projectedPortmann et al. (2013): an additional 4% of the global land area is projected
to suffer a groundwater resources decrease of more
than 30%,
6. Gosling and Arnell (2016): applied 21 GCMs to 1339
watersheds across the globe (under four SRES scenarios)
t l l t t i das a measure to calculate exposure to increases and
decreases in global water scarcity due to climate change
using:
Water Crowding Index (WCI)
Water Stress Index (WSI)Water Stress Index (WSI)
Results show that:
• 1 6 (WCI) and 2 4 (WSI) billion people are currently• 1.6 (WCI) and 2.4 (WSI) billion people are currently
living within watersheds exposed to water scarcity.
• Under A1B scenario, by 2050 nearly 0.5 to 3.1 billion
people will be exposed to an increase in water scarcity
due to climate change.
8. Competing water uses for main income groups ofp g g p
countries
According to United Nations population projections: Further the irrigated agriculture will have to be
Source: UNWWDR, 2003
According to United Nations population projections: Further, the irrigated agriculture will have to be
considerably extended in the future in order to feed growing populations (an additional 1.5–2 billion
people by 2025,
9. Water Availability and Sectorial Demands: Indian
Scenario
India receives annual precipitation of about 4000 BCM,
including snowfall, out of which almost 75 % is receivedincluding snowfall, out of which almost 75 % is received
during the monsoon season.
The total average annual flow per year for the Indiang p y
rivers is about 1869 BCM .
The annual utilizable surface water and groundwater
resources of India are 690 BCM and 431 BCM,
respectively.
10. AgricultureAgriculture
an important sector of our socio‐economic system;
contributes approximately 14% of the nation’s gross
domestic product (GDP).;
has the second largest arable land base (159.7 million
hectares) after USA and largest gross irrigated area (88) g g g (
million hectares) in the world (India Water Portal:
www.indiawaterportal.org);
Agriculture sector is the largest consumer of water Agriculture sector is the largest consumer of water .
Jain (2011) estimated:
Annual irrigation water requirement:
826 7 and 852 9 BCM respectively for 2050 and 2065 826.7 and 852.9 BCM, respectively for 2050 and 2065
approximately 40 % has to be fulfilled through
groundwater.
11. P l ti d U b i tiPopulation and Urbanization
Main components of the infrastructure sector which will be
facing increasing stress on account of growing population
because the demand for water for various uses largely
depends on the population;
J i ( ) i d
increased population will require domestic water supplies
Jain (2011) estimated:
increased population will require domestic water supplies
to the tune of 66.90, 118.58 and 122.59 BCM, respectively
for year 2025, 2050 and 2065;
the rural demands alone will require approximately
89.67% of total domestic supplies by 2065.;
By 2065 a total of 567 million tonnes of food will require
to feed the total population of 1718 million.
12. Sl. No. Particulars Unit
Year 2010* Year 2050* Revised estimates
Low High Low High
2050 2065
Future water requirement (BCM) for irrigation (Jain, 2011)
demand demand demand demand
2050 2065
1 Foodgrain demand Million tonnes 245.0 247.0 420.0 494.0 529.0 567.0
2 Net cultivable area Million hectares 143.0 143.0 145.0 145.0 145.0 145.0
3 Cropping intensity Percentage 135.0 135.0 150.0 160.0 158.0 163.0
4 Percentage of irrigated to gross cropped area Percentage 40 0 41 0 52 0 63 0 65 0 65 04 Percentage of irrigated to gross cropped area Percentage 40.0 41.0 52.0 63.0 65.0 65.0
5 Total cropped area Million hectares 193.1 193.1 217.5 232.0 229.1 236 4
6 Total irrigated cropped area Million hectares 77.2 79.2 113.1 146.2 148.9 153.6
7 Total un‐irrigated cropped area Million hectares 115.8 113.9 104.4 85.8 80.2 82.7
8 Foodcrop area as percentage of irrigated area Percentage 70.0 70.0 70.0 70.0 70.0 70 0
9 Foodcrop area as percentage of un‐irrigated area Percentage 66.0 66.0 66.0 66.0 66.0 66.0
10 Foodcrop area – irrigated Million hectares 54.1 55.4 79.2 102.3 104.2 107.5
11 Foodcrop area – un‐irrigated Million hectares 76.4 75.2 68.9 56.7 52.9 54.6
12 Average yield ‐ irrigated food crop Tonnes/hectare 3.0 3.0 4.0 4.0 4.25 4.40
13 Average yield – un‐irrigated food crop Tonnes/hectare 1 1 1 1 1 5 1 5 1 60 1 7013 Average yield un irrigated food crop Tonnes/hectare 1.1 1.1 1.5 1.5 1.60 1.70
14 Foodgrain production from irrigated area Million tonnes 162.2 166.2 316.7 409.2 443.0 473.2
15 Foodgrain production from un‐irrigated area Million tonnes 84.1 82.7 103.4 85.0 84.7 92. 8
16 Total surrogate food production Million tonnes 246.3 248.9 420.0 494.2 527.7 566.0
17 Assumed percentage of potential from
f l i i i i l
Percentage 47.0 47.0 54.3 54.3 54.3 54.3
surface water to total irrigation potential
18 Irrigated area from surface water Million hectares 36.3 37.2 61.4 79.4 80.9 83.4
19 Irrigated area from ground water Million hectares 40.9 41.9 51.7 66.6 68.1 70.2
20 Assumed 'Delta' for surface water Meter 0.91 0.91 0.61 0.61 0.61 0.61
21 Assumed 'Delta' for ground water Meter 0.52 0.52 0.49 0.40 0.49 0. 49
22 Surface water required for irrigation BCM 330.3 338.5 374.6 484.1 493.3 508.9
23 Ground water required for irrigation BCM 212.8 210.1 253.3 327.3 333.5 344.0
24 Total water required for irrigation BCM 543.1 556.7 627.9 811.4 826.7 852.9
13. Domestic water requirement in India for the years 2025, 2050 and 2065
Item Unit Year 2025 Year 2050 Year 2065
Population Million 1333 1692 1719p
Percentage urban ‐‐ 0.45 0.60 0. 65
Percentage rural ‐‐ 0.55 0.40 0. 35Percentage rural 55 4 35
Norm ‐ urban
area
Ipcd 220 220 220
Norm ‐ rural area Ipcd 70 150 150
Demand ‐ urban BCM 48.17 81.52 89.67
Demand ‐ rural BCM 18.73 37. 05 32.92
T t l BCM 66 90 118 58 122 59Total BCM 66.90 118.58 122.59
14. Water‐Food‐Energy NexusWater Food Energy Nexus
f h d f d d d l d
http://www.futurewater.nl/
a far‐reaching vision oriented transformation is needed. Water and land
constraints, as well as the impacts of inter‐sectoral demands have to be
considered in the development of water, energy and food solutions.
15. Water availability for Irrigation?
accounts for about 72% of global and 90% of developing‐country water accounts for about 72% of global and 90% of developing country water
withdrawals and thus leading to increased pressure on freshwater
resource;
further reduced due to rapidly increasing non‐agricultural water uses in
industry and households, as well as for environmental purposes.;
with the growing irrigation‐water demands and increasing competition
across water‐using sectors.
This incites to explore
h fthe concept of water
productivity (WP) in
agriculture.g
17. Irrigation Efficiency (Ei)
I h i f i i i d li d hIt represents the portion of irrigation water delivered to the
target area that has been evaporated, or consumed, expressed
as (Jensen, 2007):( )
PW
ET
E i
i
PWg
i
where ET (Evapo transpiration) is the component of irrigationwhere, ETi (Evapo-transpiration) is the component of irrigation
water delivered that was consumed by (E = evaporation from
the soil and plant surfaces and T = transpiration), Wg is the
gross supply and Pe is the effective precipitation
18. Irrigation trade‐offs in Agriculture
should be explored
for various
dimensions of the
often-neglectedoften neglected
tradeoffs between
irrigation efficiency
( ith d ti it(with productivity
enhancements) and
water for ecosystem
processes ?
Irrigation trade-offs in agriculture (Scott et al., 2014)
19. Water use efficiency (WUE)Water use efficiency (WUE)
Ratio of photosynthetic gross carbon assimilation (GPP) to
evapo‐transpiration (ET);
acts as a critical link between carbon and water cycling in
terrestrial ecosystems.
Mathematically it can be expressed as (Dong et al 2011):
T
x
GPPGPP
WUE
Mathematically, it can be expressed as (Dong et al., 2011):
ET
x
TET
WUE
where T is the vegetation transpiration GPP/T is the transpiration‐basedwhere T is the vegetation transpiration. GPP/T is the transpiration based
WUE, indicating the efficiency of plants in using water to produce dry
matter;
while T/ET, the ratio of transpiration to evapo‐transpiration, reflects how/ , p p p ,
ecosystem water vapor flux is allocated between physical and biological
processes. GPP/T and T/ET are affected by different processes.
20. Water Productivity (WP) Water Productivity (WP)
Molden (1997): WP concept was originally promoted to
t f th t f t b t di thaccount for the outcomes of water use by extending the
notion of Crop WUE (crop yield per unit seasonal evapo-
transpiration).
Kijne et al. (2003): presented a collection of papers that
discussed definitions, applications and case studies of WP.discussed definitions, applications and case studies of WP.
Rodrigues and Pereira (2009): Increasing WP can be
considered as the best a to achie e efficient ater se;considered as the best way to achieve efficient water use;
Numerous studies, both conceptual
d l h b bl h dand practical, have been published
worldwide.
21. PRODUCTIVITY
is a measure of performance expressed as the ratio of
t t t i t
PRODUCTIVITY
output to input.
Productivity may be assessed for the whole system or
parts of it.
total productivity – the ratio of total tangible
outputs divided by total tangible inputs; and
partial or single factor productivity – the ratio of
total tangible output to input of one factor within
a systema system.
In farming systems the factors could be water, land, capital, labor and nutrients
22. Water productivity (WP): like land productivity, is
therefore a partial‐factor productivity that measuresp p y
how the systems convert water into goods and services.
InputWater
Water UsefromDerivedOutput
WP
WP i d d l i iWP was introduced to complement existing measures
of the performance of irrigation systems, mainly the
classic irrigation and effective efficiency (Keller etg y
al., 1996).
23. Cai and Rosegrant (2003) defined WP as:
Crop yield per cubic meter of water consumption
(WC)*, including ‘green’ water (effective rainfall) for(WC) , including green water (effective rainfall) for
rain‐fed areas and both ‘green’ water and ‘blue’ water
(diverted water from water systems) for irrigated areas.
)m(WC
)kg(P
)m/kg(WP 3
3
)m(WC
*WC i l d b fi i l t ti (BWC) d b fi i l t ti*WC includes beneficial water consumption (BWC) and non-beneficial water consumption
(NBWC). BWC directly contributes to crop growth at the river-basin scale, and NBWC
includes distribution and conveyance losses to evaporation and sinks, which are not
economically reusable.y
**BWC is characterized by water-use efficiency (WUE) in agriculture.
24. Physical Economical Nutritional
mass of agricultural output
to the amount of water
d
monetary value derived per
unit of water consumed
nutritional content per
volume of water
d ( l dconsumed consumed (Renault and
Wallender, 2000)
a concept highlighted by the Stockholm International Waterp g g y
Institute (SIWI) and the International Water Management
Institute (IWMI) under the idea of “more nutrition per drop
26. WP and Irrigation Water Management (IWM)WP and Irrigation Water Management (IWM)
Kang et al (2016); Oktem et al (2003) and Sharma et al (1990) studied the influence of Kang et al. (2016); Oktem et al. (2003), and Sharma et al. (1990) studied the influence of
irrigation on WP;
Zwart et al (2004) found that without irrigation WP in rainfed systems is low but WP Zwart et al. (2004) found that without irrigation WP in rainfed systems is low, but WP
rapidly increases when a little irrigation water is applied;
Relationship between amounts of irrigation water applied (I) and measured crop water productivity (CWP) per unit water depletion for (a) wheat and (b)
maize. (Zwart et al., 2004).
27. Notably a maximum WP will often not coincide with farmers’ interests whose aimNotably, a maximum WP will often not coincide with farmers interests, whose aim
is maximum land productivity or economic profitability as shown in Figure 4. It
requires a shift in irrigation science, irrigation water management and basin
ll f ‘ ld’water allocation to move away from ‘maximum irrigation-maximum yield’
strategies to ‘less irrigation-maximum WP’ policies
28. Overall………
All types of
water uses:
Blue, Green,
Gray Wide variety
of outputs:
Ph i l
Hydro‐
Physical,
Economical
and
Nutritional
y
climatic
conditions
Agricultural
WP Measures of
technical and
allocative
Multiple
sources of
t efficiency
Multiple use
and sequential
Non‐water
factors that
water
q
re‐use as the
water cascades
through the
basin
affect
productivity:
Land, Crop,
fertilisers, etc.
Water Productivity: a holistic and integrated performance assessment indicator of agricultural production
system
29. Drivers of Change in Water Productivity
WP concept jointly represents the impact of engineering agronomicalWP concept jointly represents the impact of engineering agronomicalWP concept jointly represents the impact of engineering, agronomical,
ecological and economical determinants which could help improve
agricultural productivity with minimum stress to its determinants
WP concept jointly represents the impact of engineering, agronomical,
ecological and economical determinants which could help improve
agricultural productivity with minimum stress to its determinants
Actual Evapo‐transpiration (ETact)/Crop water
ti (CWC) It i f th i t t f t iconsumption (CWC): It is one of the important factors governing
the WP for a particular crop and soil type;
A i l i C di ifi i C d i d Agronomical practices: Crop diversification, Crop production and
Biomass: Efforts have to be evolved for crop diversification, less water
requiring crops with improved agricultural productivity;
30. Engineering practices: Irrigation systems reliability
and scheduling: In the arena of climate change and exceeding inter-
sectoral demands, advanced irrigation engineering techniques (with improved
reliability and resilience), on-farm irrigation scheduling, water harvesting and
management practices will have to be introduced.
Soil moisture: Soil moisture budgeting process quantification. Engineering
as well as agronomical techniques shall have to be evolved to improve soil
moisture and quantify various processes to help improve WPmoisture and quantify various processes to help improve WP.
Geo‐hydrology: To help improve groundwater contribution to enhance WP,
the geo-hydrological aspects such as occurrence and movement of groundwaterthe geo hydrological aspects such as occurrence and movement of groundwater
and its interaction with the environment shall have to be quantified at basin scale.
31. Water Footprint and Virtual Water: The concept of WF and VW can
be effectively incorporated to increase the WP Improved irrigation techniques withbe effectively incorporated to increase the WP. Improved irrigation techniques with
emphasis on “More Crop per Drop” can help improve WP and reduce WF and VW in
agricultural production;
Climate change: Mainly impacts the hydrologic cycle and water availability
patterns of a region. Hence appropriate mitigation technologies (engineering as well
as agronomical) shall have to be applied;
Economic and Policy Issues: Water pricing, Water audit and
government policy issues could have an everlasting effect on WP. These issues will
help improve efficiency at basin and farm scale.
33. Approaches in Assessing Water Productivity
Water balance approach is used to assess the WP of agricultural
production systems;
WP i l d d t d b d t th l t l l fi ld l lWP is scale dependent and can be assessed at the plant level, field level,
farm level, system level and basin level.
The amount of water used in production (denominator in Eq 3) can beThe amount of water used in production (denominator in Eq. 3) can be
estimated depending on system boundaries and details available as:
• Gross inflow, Net inflow, and available water into a given field or catchment
area;
• Depleted water: is the amount of water removed from the system by both
beneficial and non-beneficial depletion.
• Beneficially depleted water, which is the amount of water depleted through
process and non-process beneficial use; andp p
• Process depleted water, which is the amount of water depleted through
process beneficial use.
34. Ways to Increase Water Productivity in Agriculture Ways to Increase Water Productivity in Agriculture
(Technological, Management and Governance )
Increasing WP in agriculture means raising cropg g g p
yields per unit of water consumed
In China, WP for non‐rice cereals ranges from 0.4 toIn China, WP for non rice cereals ranges from 0.4 to
1.4 kg/m3;
In India WP for non rice cereal productivity rangesIn India, WP for non‐rice cereal productivity ranges
from 0.2 to 0.7 kg/m3;
In the USA WP ranges from 0 9 to 1 9 kg/m3In the USA, WP ranges from 0.9 to 1.9 kg/m3.
Among Indian states, WP varies from 1.01 kg/m3 in Punjab (the highest) to
30.21 kg/m3 in Orissa (the lowest) among states (Sharma et al., 2009).
35. Ways to increase WP…………
Rao et al. (2016) found that deficit irrigation at 0.8 ETact could be
d d f l l f d h h ld d dconsidered as useful tool for water saving and higher yield in arid and semi-
arid regions where irrigation water supplies are limited;
Patil et al. (2016) found that conservation agriculture (CA) can help
improve WP;
Bar et al. (2015) found that indicated that irrigation scheduling has
significant impact on WP;
Resource conservation technologies (RCTs): can help increase WP..
36. Framework for Increasing WP in Agriculture
Scale Water balance Target Ways required
TECHNICAL WAYS
Point/plant 1.1 Transpiration efficiency Crop improvement
Access to inputs
1.2 increased harvest index Crop science
Access to inputsAccess to inputs
Field/farmer Alter rainfall partitioning and
Increase T/E ratio
Conservation agriculture
Precision Farming
Climate smart farming
Soil water conservation
Basin/system 3.1 Rainwater harvesting &
groundwater recharge
IWRM (Landuse planning)
Watershed development
Aquifer mapping and zoning as per agroAquifer mapping and zoning as per agro‐
ecological zones (AEZ)
3.2 Irrigation improvement: systems reliability and resilience
(a): On farm focus Drip/sprinkler irrigation(a): On‐farm focus Drip/sprinkler irrigation
Deficit irrigation
Supplemental irrigation
(b): System focus Improved supply delivery( ) y p pp y y
Waste‐water re‐use
Drainage re‐use
37. POLICY AND GOVERNANCE
Consumers, private sectors pay the environmental costs of food production and
and city dwellers compensate to farming communities
Governments& Policy
M k
provide economic incentives to produce more food
ith l t t f l lMakers with less water at farm level;
fund for water resources development and
management;
fund for rural water infrastructures at farm and fund for rural water infrastructures at farm and
basin level
water use‐demand regulations
Extension and Awareness farmers field schools;Extension and Awareness
services
farmers field schools;
participatory water management programs;
water users co‐operatives at sub‐basin and basin
levellevel
Institutional: research and
academic
enhanced water research endeavors in agriculture
enhanced dissemination of research findings
increase interaction between research and farmingincrease interaction between research and farming
communities.
38. Pradhan Mantri Krishi Sinchai YojanaPradhan Mantri Krishi Sinchai Yojana
Har Hath Ko Kam, Har Khet Ko Pani
Rs. 50,000 crore over 2015‐2020 period with an additional Rs.
20,000 crore placed at the disposal of NABARD
1 A l d I B f P (R 11 060 )1. Accelerated Irrigation Benefits Program (Rs. 11,060 crore);
2. Micro-irrigation ('per drop, more crop’) (Rs. 16,300 crore);
3. Watershed program (Rs. 13,590 crore) andp g ( )
4. Har Khet Ko Pani (Rs. 9,050 crore) to construct one water harvesting
structure per village by 2020.
Water Productivity based prioritization and Zoning
Missing?Missing?
Water Productivity based prioritization and Zoning
Institutional: academic and research‐for performance assesment
39. i h f i f d d i i ill
Conclusions
1. WP is the net return for a unit of water used and increasing WP will
help produce more food, income, better livelihoods and improved
ecosystem services with less water.
2. Increasing WP will help maintain sufficient water in rivers, ponds
and lakes and would lead to reduction in groundwater withdrawals
for agriculture to sustain ecosystems and to meet the growingg y g g
demands of cities and industries.
3. More research endeavors are needed to enhance our understanding
of WP in relation to dynamic hydro‐climatological, bio‐physical,
socio‐economical systems for ensuring food security.
I li bl d ili t i i ti t ith i d4. Increase reliable and resilient irrigation systems with improved crop
varieties and application of conservation agriculture, precision
farming and climate smart agricultural systems to in agriculture.
5. Various governance and policy steps should also be implemented to
achieve the target of enhancing WP in agriculture for food security.
40. be cautious !
Crop water productivity is already quite high in highly productive regions, and gains in yield
(per unit of land area) do not necessarily translate into gains in water productivity.
Reuse of water that takes place within an irrigated area or a basin can compensate for thep g p
perceived losses at the field-scale in terms of water quantity, though the water quality is
likely to be affected.
While crop breeding has played an important role in increasing water productivity in thep g p y p g p y
past, especially by improving the harvest index, such large gains are not easily foreseen in
the future.
More importantly, enabling conditions for farmers and water managers are not always in More importantly, enabling conditions for farmers and water managers are not always in
place to enhance water productivity.
Improving water productivity will thus require an
understanding of the hydro‐climatological, bio‐
physical, as well as the socio‐economical
environments crossing scales between field, farm
and basin.