Future of Irrigation in India Anik Bhaduri, Upali Amarasinghe and Tushaar Shah 1. Introduction Over the last century, the global population has tripled, and water consumption has increased threefold (UNESCO 2005). Water use in India is no exception to this general trend. The main cause of the increase are growing population and rising food demand. In an agrarian economy like India, the importance of water for agricultural productivity hardly needs any emphasis. India faces the daunting task of increasing its food production by over50 percent in the next two decades, and reaching towards the goal of sustainable agriculture requires a crucial role of water (Kumar 1998). Empirical evidence suggests that increase in agricultural production in India mostly has taken place under irrigated conditions; close to three fifths of India’s grain harvest comes from irrigated land (Brown 2003). In this paper, we aim primarily to explore the future of irrigation in India. The projection for irrigation water demand basically depends on irrigated area, cropping pattern, crop evapotranspiration requirements, effective rainfall, soil and water quality, irrigation use efficiency and conjunctive use of water (Roy et. al2004). Assuming ceteris paribus, gross irrigated area represents the irrigation demand of India 1 There are two main sources of growth in irrigation area: expanding the irrigated area, and increasing the frequency with which it is irrigated (irrigation intensity). India’s irrigated area expanded at a steady rate during the last few decades. The net irrigated area has increased by 24% during 1980-81 to 1990-91 and by 18% from 1990-91 to 2000-01. The inference is that Indian agriculture has clear limits on the extensive margin because the net irrigated area has been growing at a very slow pace. Irrigation intensity representing the intensive margin has increased by 8.8% over the past two decades (Damodaran 2001). In the paper, we investigate the significance of the factors that may affect the irrigation intensity of the country. Many factors have contributed the growth of irrigation intensity in the last decade. We focus her e only on three cont ribu ting fact ors -agr icul tur e depende nt pop ula tio n, irrigated area and mechanization. We assess their contribution to the irrigation intensity growth in the 1990’s. The most important challenge that most reviews of India’s future irrigation is that of exploding population. India’s current population is 1100 million is expected to stabilize at some stage. The projected population is 1500 million by 2050 with agriculture remaining as the primary source of livelihood in rural areas (Ref). India’s agriculture dependent population relative to the total population has been decreasing over the last few decades. However, the total agriculture population is increasing, albeit at a decreasing rate of 1.1 percent in the 1980’s and 1.0 percent in the 1990’s. Despite the increasing agriculture dependent population, the net sown area (NSA) has remained more or less constant in the last decade. The NSA per person in the agriculture dependent population has decreased from 0.29 ha/person in 1990 to 0.26 ha/person in 2000. Thus the population pressure and the need for ade quat e liv eli hood opport unit ies for the inc rea sing pop ula tio n on the avai lab le agr icul ture land have incr eas ed sub sta ntia lly ove r thi s per iod. Bos eru pia n 1 ceteris paribus means all other things remaining same. 1
Over the last century, the global population has tripled, and water consumption has
increased threefold (UNESCO 2005). Water use in India is no exception to this general
trend. The main cause of the increase are growing population and rising food demand. Inan agrarian economy like India, the importance of water for agricultural productivity hardly
needs any emphasis. India faces the daunting task of increasing its food production by over
50 percent in the next two decades, and reaching towards the goal of sustainable agriculture
requires a crucial role of water (Kumar 1998). Empirical evidence suggests that increase inagricultural production in India mostly has taken place under irrigated conditions; close to
three fifths of India’s grain harvest comes from irrigated land (Brown 2003).
In this paper, we aim primarily to explore the future of irrigation in India. The
projection for irrigation water demand basically depends on irrigated area, cropping pattern, crop evapotranspiration requirements, effective rainfall, soil and water quality,
irrigation use efficiency and conjunctive use of water (Roy et. al 2004). Assuming ceteris paribus, gross irrigated area represents the irrigation demand of India1 There are two main
sources of growth in irrigation area: expanding the irrigated area, and increasing the
frequency with which it is irrigated (irrigation intensity).India’s irrigated area expanded at a steady rate during the last few decades. The net
irrigated area has increased by 24% during 1980-81 to 1990-91 and by 18% from 1990-91
to 2000-01. The inference is that Indian agriculture has clear limits on the extensive margin
because the net irrigated area has been growing at a very slow pace. Irrigation intensityrepresenting the intensive margin has increased by 8.8% over the past two decades
(Damodaran 2001). In the paper, we investigate the significance of the factors that mayaffect the irrigation intensity of the country.Many factors have contributed the growth of irrigation intensity in the last decade.
We focus here only on three contributing factors-agriculture dependent population,
irrigated area and mechanization. We assess their contribution to the irrigation intensitygrowth in the 1990’s.
The most important challenge that most reviews of India’s future irrigation is that
of exploding population. India’s current population is 1100 million is expected to stabilize
at some stage. The projected population is 1500 million by 2050 with agriculture remainingas the primary source of livelihood in rural areas (Ref). India’s agriculture dependent
population relative to the total population has been decreasing over the last few decades.
However, the total agriculture population is increasing, albeit at a decreasing rate of 1.1 percent in the 1980’s and 1.0 percent in the 1990’s. Despite the increasing agriculture
dependent population, the net sown area (NSA) has remained more or less constant in the
last decade. The NSA per person in the agriculture dependent population has decreasedfrom 0.29 ha/person in 1990 to 0.26 ha/person in 2000. Thus the population pressure and
the need for adequate livelihood opportunities for the increasing population on the
available agriculture land have increased substantially over this period. Boserupian
1 ceteris paribus means all other things remaining same.
hypothesis states that increase in population density increases the intensification of
agricultural factor use (Boserup 1981). Our paper investigates whether the increase
agricultural dependent population will influence the irrigation intensity of the country infuture and support the Boserupian hypothesis.
Over the past 15 years, increase in irrigated area has mainly taken place from
groundwater source. There are two main reasons for higher expansion of groundwater irrigation. First, due to slow down in the growth of public investments in large-scale
irrigation infrastructure and incompletion of on going projects, the surface irrigated area
has not increased in the 1990’s. The most severe problem facing Indian canal irrigation,however, is the rapid deterioration of systems that have already been created. Maintenance
is being woefully neglected, leading to poor capacity utilization, rising incidence of water
logging and salinity and lower water use efficiency (WUE). On the whole large canal based
irrigation is threatening to become unsustainable physically, environmentally as well asfinancially (Gulati 1999). In the absence of new large-scale surface irrigation schemes, and
the availability of low cost electric and diesel pumps coupled with little or no electricity
charges, the groundwater has been a major driver in the irrigated area expansion. Second,
yields in areas irrigated by groundwater are often substantially higher than the yield fromsurface water sources. FAO research indicates that yields in groundwater irrigated areas are
higher by one third to one half than in areas irrigated from surface sources, and as much as70-80% of India’s agricultural output may be groundwater dependent (FAO 2005). Higher
yields from groundwater-irrigated areas are in large part due to increase in the reliability of
water supply. In the paper, we explore how irrigated area driven by groundwater irrigationexpansion will contribute in increasing the irrigation intensity.
There has been considerable growth of mechanization in agriculture during the last
decade. Mechanization is higher in states where labour employment is lower and
proportion of irrigated area is higher. In future, with growing urbanization and outmigration, mechanization will play a vital role in achieving higher agricultural production
in irrigated area. In this paper, we assess the significance of mechanization in increasing
the cropping intensity under irrigated condition.We hypothesize both time series and cross section variation in irrigation intensity
and the factors influencing the latter across the states in India. Using a panel data, we
investigate the irrigation intensity, and assess the future impacts of increasing agricultural population, grain orientation of agriculture in terms of area for foodgrain cultivation and
irrigated area. We also assess the influence of mechanization in increasing the irrigation
intensity. We have used annual time series and cross section data of 15 major states in
India, which constitutes more than 95 % of the agrarian economy of India, for the period1990-2001. Based on the regression results, we analyze the contribution of the different
factors in the relative changes in irrigation intensity growth.
It is essential to project India’s future irrigation scenarios, as now India is on a crossroad to decide about the ways to meet future water demand. The most relevant question is
regarding the magnitude of the change in irrigated area India is expecting in future. The
proportion irrigated area and other factors are determined using a quadratic time trend of the last decade; and then based on the regression results and time trend values of the
factors, we project the irrigation intensity of India in 2010, 2025 and 2050.
The structure of the paper is as follows. In the first section, we discuss about the
past irrigation scenarios .In the next section, we explore the irrigation intensity and the
relative contribution of the factors in changing it’s growth. In the fourth section, we make
future projections of irrigation intensity, net and gross irrigated area. Finally, the last
section summarizes the findings and results of the paper.
2. Irrigation Scenario in India.
In the last forty years, the share of Indian agriculture in gross domestic product hasdecreased, but extensive use of HYV seeds, modern irrigation tech, and fertilizer have
contributed in increasing the agricultural productivity and achieving self sufficiency in
meeting food demand. Given increasing trend of population, policy makers find itimperative for India to achieve higher agriculture production and continue to meet the food
security objective of the country; and indicated that irrigation will play a key role in future
in achieving higher yield and sustaining the food security (Persaud et al . 2003). During the
last fifty years, gross irrigated area (GIA) of India has increased more than three fold from22 to 76 million Hectares. Gross irrigated area is a straightforward multiplicative function
of net irrigated area (NIA) and irrigation intensity (IRI), and thus the relevant question
which may arise is regarding the contribution of net irrigated area (NIA) relative to the
irrigation intensity (IRI) in increasing the GIA. Figure 2.1 shows the change in net andgross irrigated area .The vertical distance between the two curves signifies the irrigation
intensity. The figure below illustrates the increasing role of irrigation intensity which hasincreases by more than 4 % in the last decade.
0
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M i l l i o n H a
Net
irrigated
area
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irrigated
area
Figure 2.1: Gross and Net irrigated area of India during 1950-2000
There are state wise variation in irrigation, and is reflected in figure 2.2. It shows the state
wise position of irrigation in year 2000-01.The level of irrigation is measured in terms of irrigation intensity and irrigation ratio, defined as NIA/NSA .
Figure 2.2 shows high proportion of irrigated land of more than 70% in agricultural states
like Punjab, Haryana and Uttar Pradesh where agriculture constitutes more than 30% of the
state GDP. Among the southern states, proportion of irrigated land is below 30% inKarnataka and Kerala; while in Andhra Pradesh and Tamil Nadu, NIA/NSA is above 40%.
Among the western states, Maharashtra has the lowest proportion of irrigated land where
Most of the eastern states are well endowed with irrigation where average NIA/NSA is
0.40.In the north-eastern state of Assam, however, less than 10% of net cropped area is
irrigated.We analyze the growth of irrigation intensity, NIA, GIA and IR ratio across states
in the last decade. Many climatic factors like rainfall, drought affects irrigation. So, we
have taken a four-year average for the period 1990-1993 and 1997-2000.Table 2.1 showsthe average of IR, NIA, IRI and the corresponding growth rate.
In Punjab and Kerala, there is decrease in the proportion of irrigated area, even with
an increase in NIA. It suggests that in post 1997 period, more rainfed area has been broughtunder cultivation in both the states. In the northern zone, there is no further room for
irrigation development as 75% of the net cropped is irrigated, and is reflected in lower
growth. The growth of irrigation area is striking in the western zone where NIA has grown
by 46% from 1990-1993 to 1997-2000.Eastern states register a much slower growth of irrigation except West Bengal. Among the southern states, higher growth in NIA took place
in Andhra Pradesh and Tamil Nadu.
0
0.2
0.4
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0.8
1
1.2
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1.6
1.8
2
AP AS BH GUJ HAR HP K AR KER MP M AH OR I P UN RAJ TN UP WB
states
Irrigation statewise -2000-01
Irrigation intensity
irrigation ratio
Figure2.2: state wise irrigation intensity and proportional area during the year 2000-01.
Many states register a decrease in irrigation intensity( IRI), and much of thedecrease are noticed in states like Himachal Pradesh, Orissa, Tamil Nadu and Maharashtra.
In these states, the proportional irrigated area is not high except in Tamil Nadu. The
opportunity cost of increasing the irrigation intensity is higher than increasing the net
irrigated area. As a result, NIA has increased in these states with the development of minor irrigation.
In West Bengal, however, IRI has increased by 39% in the post 1997 period. Onemay argue that the higher opportunity cost of increasing the extensive margin leads to
higher irrigation intensity. The alternative hypothesis is that high endowment of irrigation
land increases the reliability of irrigation water and induces higher irrigation intensity. Wetest the hypothesis using regression whether increase in irrigated area could be the cause of
higher irrigation intensity. We also hypothesize whether endowment of irrigated area is
factor in the marginal effect on irrigation intensity.
Groundwater Irrigation: Groundwater irrigation in India developed during the period of
green revolution and contributed much in increasing the gross irrigated area of the country.
In the last five decades, groundwater irrigation has increased from 5 million hectares to35million hectares. Figure 2.3 illustrates the growth in groundwater in the last fifty years.
The proportional area of groundwater to the net irrigated area has increased by 22% alone
during the period 1990-2000.The figure also highlight the groundwater irrigation expansionrelative to that of the net irrigated area; and not major difference in the slopes of the two
curves is reflected in the last few decades.
0
10
20
30
40
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60
1 9 5 0 - 5 1
1 9 5 5 - 5 6
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2 0 0 0 - 0 1
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m i l l i o n H a .
groundwater
Net Irrigated Area
surface water
Figure 2.3: Groundwater and surface irrigated area during the last fifty years.2
2 Note: surface water includes both canal and tank irrigated area
In the past, surface water irrigation played a significant role in increasing the net
irrigated area. However from mid sixties, the proportion of surface water to net irrigated
area has decreased and in the last decade alone it has decreased largely by 23%.This islargely due to incompletion of planned irrigation projects and poor maintenance of the
existing surface irrigation infrastructure.
State wise there is wide variation in the source of net irrigated area. In the northern andwestern states, the proportional of groundwater irrigation to net irrigated area is more than
70% in the post period 1997 while the share of groundwater and surface water is equal in
the southern zone during the same period. Groundwater expansion growth is higher in thestates like Assam and West Bengal. Assam has abundant and untapped ground water
potential and the state Government has prioritised massive irrigation facility with the
concept of Participatory Irrigation Management.
Groundwater expansion growth rate is insignificant in Bihar while in Karnataka weobserve decline in the proportion of groundwater-irrigated area. With NIA has increased by
10% the decline in groundwater proportion has caused by declining groundwater level.
Figure 2.4 shows the composition of groundwater and surface water across states. During
the year 2000-2001, groundwater accounts for 67% of the net irrigated area. Groundwater expansion has been growing at an exceptional rate in the recent decades. More reliable
water delivery and declining extraction costs due to advances in technology and, in manyinstances, government subsidies for power and pump installation have encourages private
investment in tube wells.
States 1990-1993 1997-2000Growth Rates (Per Cent 1997-2000 over 1990-1993)
SWA GWA SWA GWA SWA GWA
Haryana 0.52 0.48 0.48 0.52 -7.77 8.41
Punjab 0.38 0.62 0.25 0.75 -34.49 20.81
Himachal Pradesh 0.16 0.84 0.03 0.97 -78.22 14.75
Uttar Pradesh 0.32 0.68 0.25 0.75 -20.51 9.55
North Zone 0.36 0.64 0.28 0.72 -21.55 12.19
West Bengal 0.51 0.49 0.33 0.67 -35.35 37.21
Bihar- 0.36 0.64 0.35 0.65 -2.27 1.25
Orissa 0.65 0.35 0.60 0.40 -7.36 13.53
Assam 0.63 0.37 0.45 0.55 -29.56 50
East Zone 0.49 0.51 0.41 0.59 -15.40 14.61
Karnataka 0.30 0.70 0.48 0.52 62.06 -26.07
Kerala 0.47 0.53 0.40 0.60 -16.47 14.83
Tamil Nadu 0.58 0.42 0.50 0.50 -12.63 17.22
Andhra Pradesh 0.68 0.32 0.53 0.47 -22.30 47
South Zone 0.56 0.44 0.50 0.50 -9.25 11.59
Gujarat 0.25 0.75 0.19 0.81 -21.37 7.02
Maharashtra 0.42 0.58 0.35 0.65 -15.82 11.46
MP 0.38 0.62 0.31 0.69 -18.26 10.96
Rajasthan 0.41 0.59 0.30 0.70 -27.03 18.94
West Zone 0.37 0.63 0.29 0.71 -20.91 12.35
INDIA 0.41 0.59 0.35 0.65 -14.79 10.33
Table 2.2: State wise source of irrigation during the period 1990-1993 and 1997-2000.
Note: SWA denotes =Area irrigated from canals and tanks/net irrigated area; GWA= Area irrigated from
Groundwater irrigation, due to its lesser variation in its supply and higher the
reliability in irrigated water supply, reduces the risk of investment in labour, seed,
fertilizers, pesticides and other inputs and induces farmers to increase the irrigationintensity. Some states has experienced fast decline in groundwater level which leads to
lower productivity of water and cause a decrease in irrigation intensity. Irrigation intensity
is lower among southern states where the groundwater depletion problem is severe.
Groundwater and Surface water irrigation 2000-01
0
0.2
0.4
0.6
0.8
1
1.2
AP AS BH GUJ HAR HP KAR KER MP MAH ORI PUN RAJ TN UP WB India
states
GWA
SWA
Table 2.4: State wise source of irrigation during the year 2000-01.Mechanization:
The mechanization involves judicious application of inputs by using agricultural
machinery/equipment e.g. hand tools, bullock drawn equipment, power driven machines
including the prime movers for performing various operations required for crop production
activities. The mechanization ensures reduction of drudgery associated with various farmoperations as also economize the utilization of inputs and thereby harnessing the potential
of available resources. The table 2.3 shows the level of mechanization in different parts of
the country. The adoption of mechanization is linked with endowment of irrigation. Thestates with adequate irrigation facilities, the mechanization has progressed at faster rate in
comparison to States that have scant irrigation facilities and dependent on monsoon.Irrigation reduces the farmer’s risk in investment on land and thus encourages adoptingmechanization to increase production. Mechanization is a key factor, which can help in
increasing the cropping intensity under irrigated conditions. Our hypothesis is that higher
proportional irrigated area encourages farmers to adopt mechanization, which facilitates inincreasing the irrigation intensity.
Table 2.3: State wise level of mechanization during the period 1990-1993 and 1997-2000.
*Expressed in real terms -deflated by consumer price index of agricultural labour.
Agricultural dependent Population:
In India, 54% of the population is dependent on agriculture according to the 2001census. The agricultural dependent population (ADP) has increased from 500 million to
539 million during the last decade with a decadal growth rate of 7.95%.As net cropped areahas stayed nearly same, ADP per hectare has increased by 8.49%.Table 2.4 shows that
agricultural dependent population has increased in most of the states. Zone wise, we
observe the highest growth of ADP in east zone, and a negative growth in southern zone.
However, agricultural dependent population per hectare of cropped area has increased in allstates. Proportion of ADP to total population has decreased in most of the states; however,
it has increased in Haryana and Himachal Pradesh.
There could be two possible effects of increasing agricultural dependent populationat a macro level. First, increase in agricultural dependent population increases the demand
for food to maintain rural livelihood. With limits on increasing the extensive margin of
irrigation, intensity in irrigated area could increase to increase the agricultural productionand to meet the food demand. Second, agricultural dependent population constitutes higher
proportion of agricultural labour. Increase in agricultural labour force reduce the wage rate
We hypothesize that increase in agricultural dependent population will increase the
irrigation intensity, which supports the Boserupian hypothesis that increase in population
density increases the agricultural factor use intensification.
Table 2.4 also shows some exceptions to the general trend of increasing agricultural
dependent population. Agricultural dependent population has decreased in Maharashtra and
Tamil Nadu. In addition ADP per hectare of cropped area has decreased in Orissa andKerala that is mainly contributed higher proportional increase in NSA. The decrease in
agricultural dependent population is mainly contributed by migration for other non-agricultural activities.
Development economists view the gap in rural and urban wages as the main pull
factor for migration. Urbanization coupled with slow growth rate in the agricultural sector
has been the major driver of internal migration. Studies in Bihar suggest that migrationfrom the latter state is now mainly to urban areas and not to traditional destinations in
irrigated urban incomes Punjab where work availability has declined (Karan 2003). Also,
in dry parts of Gujarat the urban income are so lucrative that not even irrigation couldreduce migration (Shylendra et al.1994). In Tamil Nadu, where more than 50% of the
cropped area is irrigated, out migration took place to such a extent such that the agriculturaldependent population has declined in absolute number. So lack of irrigation may not be the
only reason for decline in agricultural dependent population. 3
3.Irrigtion intensity:
Intensity of irrigation is a crucial indicator reflecting effective gross availability of water per unit area of cultivable land. If a unit area could be provided with irrigation for more
than one crop season, then the irrigation intensity naturally increases. Also, raising more
than one irrigated crop in any area leads to a better use of inputs and also better utilizationof residual soil moisture available from the previous crop resulting in higher crop yield and
output levels. During the last decade, irrigation intensity of India has increased from 1.32
to 1.37, and 4.6 % increase in irrigation intensity contributes 33% in the gross irrigated areaof India. As part of the objective to estimate the gross irrigated area in India, we firstestimate irrigation intensity. In this section using regression analysis, we have attempted to
review the relationship of irrigation intensity with irrigated area, agricultural dependent
population and mechanization.Using regression analysis we test the following hypothesis
a) Higher irrigated area increases the reliability of water and induces higher irrigation
intensity. b) Increase in agricultural dependent population per hectare of cropped area will increases
the demand for food and supply of labour and increases the irrigation intensity.
c) Mechanization is dependent on irrigated conditions and increases irrigation intensity.
Table 3.1: Description of variables
3 One may argue that higher irrigation intensity may provide continuous gainful employment and thus
irrigation intensity may influence the agricultural dependent population, which constitutes a growing
proportion of agricultural labour. We have performed granger causality test. The results of the test indicate
irrigation intensity does not granger – cause agricultural dependent population at 10% level of significance.
The result holds for one to three period lags.Detail results are provided in the appendix.
Variables Definitions
Irrigation intensity (IRI) Ratio of gross irrigated area (GIA) to net irrigated area
(NIA) IRI=GIA/NIA
Irrigation ratio ( IR) Proportion of irrigated area to net cropped area (NIA/NSA)
Agricultural dependent population
(AP)
Number of agricultural dependent population per Ha of net
sown area
Mechanisation (Mech) Use of tractors, threshers and baler in cultivation for
substitution of labour. It is expressed in real terms.
Ground water irrigation (Gwater)Prop proportion of irrigated area from wells to net irrigated area.
We have used annual time series and cross section data of 15 major states in India,which constitutes more than 95 % of the agrarian economy of India, for the period 1990-
2001. Unlike earlier studies, instead of using aggregate time series data for these crops , weuse panel data , where the cross sectional units are the different states. This allows for state
–specific variation in all the variables included, as compared to all- India data which couldreduce such variation by aggregating some variables and averaging others.
Panel estimation allows us to incorporate sources of variation which can be
incorporated otherwise. Furthermore, panel data facilitate with a large number of data points, and thus increasing the degrees of freedom and reducing the collinearity among
explanatory variables. Hence, it improves the efficiency of estimates. Irrigation intensity
depends on many unobserved variables. Panel data reduce the endogeniety or the
heteroscedasticity problem, inherent in the estimation, by utilizing the information on both
the intertemporal dynamic and the individuality of the entries, which are the different stateshere. However, as we are estimating variance parameters for each panel (or possibly
covariances between panels), the estimates require many time-periods per panel for consistency; and in our data set we have included ten years long time frame for each panel
to gain consistency in estimation.
All the data were available from various sources in the public domain. In regards to
the agricultural dependent population there is lack of time series data between the censusyears 1991 and 2001. We have used FAO projections of all India agricultural dependent
population. Using the FAO projected trend and the state –wise population during the
census years 1991 and 2001,we have derived the time series data of agricultural dependent
population state-wise. We have used number of agricultural dependent population per Haof net sown area as an explanatory variable to capture the influence of increasing pressure
of population on agricultural land.
We have also adopted different approaches to reduce the endogeniety problem and toachieve unbiased consistent estimates. We have used four different regression techniques
for estimation. First we have used panel-corrected standard error (PCSE) estimates for
linear cross-sectional time-series models where the parameters are estimated by Prais-Winsten regression. When computing the standard errors and the variance-covariance
estimates, the estimation assumes that the disturbances are, by default, heteroscedasticity
and contemporaneously correlated across panels. Second, we have used random effect
model where the individual state specific effects were treated as random variables. Agrowing body of literature shows that this technique is superior to alternative techniques
such as fixed effect model where the omitted individual specific effects as fixed constants
over time. Using Hausman test, we test the structural differences in estimation, anddetermine the best technique in estimation of irrigation intensity. The wide use of different
techniques provide us an array of results and help us in selecting the best approach in
accordance with the unbiasedness, efficiency and consistency of the estimators.
Our estimates suggest that proportional irrigated area (IR), agricultural dependent
population per Ha of cropped area (AP), are significant in explaining the irrigation intensity(IRI) of the country across 15 states during the period 1990-2000. The irrigated ratio (IR),
agricultural dependent population per Ha of cropped area influence irrigation intensity
positively. The between R sqr in the random effect model also suggests high significanceof the variables in explaining the irrigation intensity between the states.
To get the further insights we have estimated the irrigation intensity in two time periods
1990-1995 and 1996-2000. The value of R square is higher in the period 1996-2000 than inthe period 1990-1994.It suggests high explanatory power of the independent variables over
time. The marginal effect of agricultural dependent population decreases slightly in the
period 1996-2000. It may be caused by growing migration pf agricultural dependent
population for non agricultural activities. The influence of IR on irrigation intensity,however, has increased in the post 1995, which is due to growing groundwater irrigation.
This is evident from the regression results of table 3.3.
Table 3.5 shows the quadratic relationship between irrigation intensity and irrigated area.
The regression results indicate 02
2
>∂
∂
IR
IRI which implies that the marginal effect on
irrigation intensity is higher with higher irrigation endowment. It explains that in stateswith low irrigation endowment, more risk are involved in increasing the irrigation intensity
while the opportunity cost of increasing the increasing the extensive margin or the net
irrigated area is lower which induces to increase the irrigated area. If the change in irrigated
area is cropped only once, then it decreases the overall irrigated intensity.In states with high endowment of irrigated area, the risk involved in
increasing the intensity is much less because of higher reliability of water supply. Also the
opportunity cost of increasing the extensive margin is higher. It leads to higher irrigationintensity.
Dependent
variable-Irrigation
Intensity
Irrigation Ratio(IR)
-NIA/NSA
Agricultural
Dependent
Population per
Ha of croppedarea (AP)
Constant R 2
1990-2000 0.707832(11.71)
0.022156(4.05)
1.035721(9.26)
.58
1990-1995 0.631849
(8.24)
0.023942
(2.33)
1.089934
(-6.73).46
1996-2000 0.76945(36.71)
0.018756(5.67)
0.938998(25.9)
.65
Table 3.2: Regression results of Irrigation Intensity as dependent variable.
Table 3.5: Regression results: Quadratic Relationship between Irrigation intensity and area.
Mechanization is one key factor, which facilitates in increasing the irrigation intensity or the cropping intensity under irrigated conditions. Mechanization helps to crop a land
several times. There is a general hypothesis that mechanization takes place mostly under
irrigated conditions. Our regression results are consistent with the findings of the earlier
studies, and suggest that mechanization in cultivation has positive influence on irrigationintensity. There has substantive growth of mechanization in agriculture over the last
decade. It is largely due to expansion of irrigated area. Expansion of irrigated area
increases income and reduces the associated risk in agricultural production and encourages
farmers to adopt higher mechanization for cultivation. Table 3.6 shows the recursiveregression results explaining the relationship between irrigation and mechanization. The
results indicate the growing role of mechanization in influencing the irrigation intensity.The marginal effects of irrigated area on mechanization and mechanization on irrigation
intensity have increased during the period 1997-2000 compare to 1990-1993.
Table 3.6: Regression results: Relationship between Irrigation and Mechanization.
Source of Irrigation Intensity growth
Here in this section, we analyse the sources of changes in irrigation intensity, which
has increased by 4.7% during the last decade. The computation of the source of irrigationintensity growth is based on the sensitivity analysis. Table 3.7 shows the contribution of
different sources to the relative change in average irrigation intensity. The first shows the
factor contributing to irrigation intensity change. The second and the third column indicate
absolute and percentage contribution of different factors to the relative change in averageyield during the period 1990-2000. The table 3.7 shows that growth in irrigated area
explains the irrigation intensity growth to a significant extent during the period 1990-2000.
The last decade witnessed a significant growth in ground water irrigation, and is reflectedin nearly 90% of the change in irrigation intensity from irrigated area. Increase in irrigated
area creates appropriate condition for the adoption of mechanization, which is another
important contributing factor in the relative change in irrigation intensity.The increase in agricultural population only contributes around 10% of the change
in irrigation intensity. After the 1991 economic reform, there has been an increased
employment opportunities in the non-farm rural sector and urban sector, which has
attracted the surplus labour from agriculture, and contributes lesser pressure on land than inthe pre –1990 period. However, in the east zone, with high population density, increase in
agricultural dependent population contributes 55% of the change in irrigation intensity. In
the south and west zone, with lesser growth of rural population, agricultural dependent population accounts less than 10% of the change in irrigation intensity.
Change Contribution (%)
India
Irrigated ratio ( IR=NIA/NSA) 0.026769 89.23
Agricultural dependent population per Ha croppedarea (AP) 0.003231 10.77
North Zone Irrigated ratio ( IR=NIA/NSA) 0.035184 87.96
Agricultural dependent population per Ha croppedarea (AP) 0.004816 12.04
Total 0.04 100.00
East Zone Irrigated ratio ( IR=NIA/NSA) 0.04884 44.40
Agricultural dependent population per Ha croppedarea (AP) 0.061160 55.60
Total 0.11 100.00
South Zone Irrigated ratio ( IR=NIA/NSA) 0.018494 92.47
Agricultural dependent population per Ha croppedarea (AP) 0.001506 7.53
Total 0.02 100.00
West Zone
Irrigated ratio ( IR=NIA/NSA) 0.009013 90.13 Agricultural dependent population per Ha croppedarea (AP) 0.000987 9.87
Total 0.01 100.00
Table 3.7: Contribution to relative change of irrigation intensity from different sources in India
4. Projection:
The question that plays in the mind of policy makers is the future of irrigation in
India. Increasing population will cause an increase in demand for foodgrain in future. Is the
current irrigation infrastructure enough to feed the growing population? Answering thequestion requires us to know the future gross irrigated area of India. Based on the
estimation results and the projected values of the explanatory variables, we project theirrigation scenario of India in year 2010, 2025 and 2050. The time dimension for the projections has also been adopted by both National Commission on Integrated Water
Resource Development Plan (NCIWDP) and the Indian Water resource Society (IWRS). A
longer time frame with target year, 2050 has been chosen as many water development projects involve a long gestation period, while a shorter time span with 2025 as a target
year has been chosen to allow institutional changes in Indian irrigation scenario. Year 2010
represent closer to present scenario as much growth in factors influencing irrigation are notexpected to take place during the next five years.
From the regression results, we have determined the marginal effect of the factors
influencing irrigation intensity. The growth rates of agricultural dependent population per
hectare of cropped area and proportional irrigated area are determined using a quadratictime trend from the last decade. Then using the regression results explaining the irrigation
intensity, we project the latter. Such estimation procedure has been taken to achieve
realistic and reasonable growth rates of the factors determining irrigation intensity.
Table 4.1: Regression Results: Quadratic time trend
Table 4.2 shows the different scenarios that may guide the development of irrigated water
demand in India in future. The first scenario, which may be looked as a business as usual
scenario, illustrates the growth of the factors based according to the time trend during the period 1990-2000.Such scenario is plausible with no major changes in the government
agricultural and irrigation policy in the next 45 years. In a longer time frame, many may
view this as unreasonable given India had experienced two major structural economic policy changes in the first fifty years of its independence. Keeping the possibility of some
changes in policy with the potential of altering the factors responsible for changes in
irrigation intensity, we have developed alternative scenarios. The alternative scenarios aredeveloped based on the faster rate of change the factors, irrigation ratio (NIA/NSA),
agricultural dependent population per hectare of cropped area.4
In the last decade groundwater irrigation has played a crucial role in influencing the
net irrigated area and meeting the irrigated water demand of India in the past. With goodgroundwater governance, and higher productivity of groundwater, the contribution of
groundwater may increase in future. The role of surface water irrigation may also increase
with the implementation of national interlinking of rivers project. In the fourth scenarioanalysis, we assume a 50% per year faster growth of irrigated area.
Economic growth driven by secondary and tertiary sectors may induce a change in
growth rate of agricultural dependent population in future. The second scenario assumesthe condition if the growth of agriculture dependent population per hectare of cropped area
is 50% lower per year, with all other factors maintaining the time trend.
In the final scenario, we consider the case where both the factors may change at a
faster rate specified by scenario 2and 3.
Scenario 1 Agricultural dependent population, irrigated area and proportional area for foodgrain all changing according to the
time trend
Scenario 2The rate of increase in the proportional irrigated area is 5%
more than time trend.
Scenario 3 The growth rate of Agricultural dependent population per
hectare of cropped area is 50% less than time trend.Scenario 4-all factors
changing
Both factors changing more than time trend.
4 The arbitrariness lies in the addition rate of the change of the factors in future. With more information
such arbitrariness can be reduced to great extent and can facilitate a better projection.
In the past, India’s groundwater irrigation has played an influencing role in
increasing the irrigated area. According to the time trend, the growth rate of proportional
irrigated area driven by groundwater irrigation would be 0.51% in 2010,0.43% in 2025 and0.28% in 2050,and at those growth rates the proportional irrigated area would be 0.47, 0.54
and 0.63 respectively. The growth assumes no major changes in surface water. However, if
we assume 50% higher growth rate in proportional irrigated area for exogenous reasons,
the proportional irrigated area will increase to 0.77 in 2050.Our projection suggest in India, the agricultural dependent population will decrease
at the rate of 1.73% in 2010,1.62% in 2025 and by 1.42% in 2050 following the 1990-2000
time trend. Given such growth rate, the agricultural dependent population per hectare isexpected to be 4.14 and 4.77 in 2025 and 2050 respectively. In the scenario with 50%
lower growth rate the corresponding figures would be 3.95 in 2010 and 4.26 in 2050.
Year Irrigation Ratio
(IR)
Agricultural
Dependent
Population per Ha
of cropped area
(AP)
20100.512858 1.738674
2025 0.425528 1.619484
2050 0.279978 1.420834
Table 4.3: Growth rate according to time trend
Table 4.4: Projected values of proportional irrigation ratio, agricultural dependent population per hectare of
Scenarios Irrigation Ratio (IR) Agricultural DependentPopulation per Ha of
Given the projected irrigated area and agricultural dependent population per hectare
of cropped area, we have estimated the irrigation intensity of India in 2010, 2025 and 2050.
In 1999-2000 the irrigation intensity of all the major states in India was 1.37. Our projection results suggest that under business as usual scenario, irrigation intensity will
increase to 1.46 in 2010 and to 1.60 million hectares in 2050. In scenario 2 with higher
contribution of irrigated area, the irrigation intensity will increase to 1.69. Slower change inagricultural dependent population, however, would not change the projected irrigation
intensity much.
In the recent past, we observe no change in the net sown area. Taking the average
net-cropped area as 140 million hectares, the NIA of India will be 66, 76 and 88 millionhectares in 2010, 2025 and 2050 respectively. Groundwater irrigation has contributed more
than 90% of the change in NIA during the past decade. If similar trend continues and
assuming 70% of the irrigated area is from groundwater irrigation, then the groundwater
net irrigated area would be 61 million Ha in 2050. The projected irrigated area, however,depends on the sustainability of the groundwater irrigation. Over exploitation of
groundwater, however, could lead to lower level of projected NIA and lower irrigationintensity.
year NIA GIA
201066.29 96.96
2025 76.14 115.58
2050 88.49 140.60Table 4.4: Projected values of net and gross irrigated area in 2010, 2025 and 2050.
5.Conclusion
In this paper, we have explored irrigation scenario in India, and sensitivitiesof the factors determining the irrigation intensity of India based on the data of the previous
decade. As Indian economy witnessed no major structural changes in policy after 1990, our
data captures only the endogenous changes and is free of exogenous shocks to great extent.
Our regressions estimates suggest that agricultural dependent population per hectare of
cropped area and irrigated area are significant in explaining the irrigation intensity of thecountry. Our results indicate that agricultural dependent on per hectare population per Ha
of cropped area and proportional irrigated area influence irrigation intensity positively.Much of the increase in net irrigated area is contributed by ground water
development, which has taken place all over the country. Groundwater irrigation, due to its
lesser variation in its supply and higher reliability, reduces the risk of agriculturalinvestment and induces farmers to increase the irrigation intensity. Also, higher
Security. National Centre for Agricultural Economics and Policy Research, page
191-205.
9. Shylendra H.S and P. Thomas 1995. Non –Farm Employment: nature, magnitudeand determinants in a semi arid village of western India. Indian Journal of
agricultural Economics 50(3): 410-416.
10. Gulati, A, Ruth Meinzen-Dick, Raju , K. V 1999. From Top Down to Bottoms Up:Institutional Reforms in Indian Canal Irrigation. Delhi: Institute of Economic
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