EFFICIENT MANAGEMENT OF RAINWATER FOR INCREASED CROP
PRODUCTIVITY AND GROUNDWATER RECHARGE IN THE SAT
S. P. Wani, P. Pathak and P. Singh
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)
Patancheru 502 324, Andhra Pradesh India
Abstract
Water is becoming a limiting factor for sustainable development in many parts of the world. It is
estimated by IWMI that 33 per cent population of the developing countries will be affected by severe
water scarcity by 2025, including one billion of the world’s poorest people living in semi-arid and arid
tropical regions. The solution to achieve sustainable development in the developing countries lies in the
efficient management of water and other natural resources for increasing the productivity.
Rainwater is the main source of water and it’s current use efficiency for crop production ranges between
30 to 45 per cent and annually 300 to 800 millimeters of seasonal rainfall is lost as surface runoff or deep
drainage. ICRISAT’s long experience in partnership with national agricultural research systems in the
area of integrated watershed management has clearly demonstrated that areas with good soils in the
SAT Asia can support double cropping and surplus rainwater could be available for recharging the
groundwater. In the integrated watershed approach the emphasis is on in-situ conservation of rainwater
at farm level, excess water is taken out from the fields safely through community drainage channels and
stored in suitable low-cost structures. The stored water is used as surface irrigation or used for
recharging groundwater. Following conservation of rainwater it’s efficient use is achieved through
appropriate crops, improved varieties, cropping systems, nutrient and pest management options for
increasing the productivity and conserving the natural resources. Long-term on-station watershed
experiments demonstrated that Vertisols in the region with 800 millimeters rainfall have the capacity to
feed 18 persons/ha (4.7 t food grains/ha) as against their current productivity of 0.9 t/ha supporting 4
persons/ha. Increased productivity is achieved through doubling the rainwater use efficiency (67 vs 37%)
and reducing the soil loss by 75 per cent as compared to the traditional methods of cultivation. By
adopting such a holistic approach to manage rainwater in partnership with the communities, crop
productivity in the watersheds is substantially increased (up to 250 %) and groundwater levels are
improved and soil loss is minimized. Results of on-farm integrated watersheds are discussed. Important
element in managing the rainwater efficiently are: community participation, capacity building at local
level through technical backstopping by a consortium of the organizations and use of high science tools
to manage the watersheds efficiently. In order to sustain the productivity in the SAT, the holistic approach
of integrated watershed management need to be scaled-up through appropriate policy and institutional
support and it’s on-site and off-site impacts need to be studied.
Introduction
Water is the primary constraint defining the semi-arid tropics (SAT) and is a limiting resource for
sustainable agriculture in the SAT. If not managed properly, it affects crop productivity significantly and
causes land degradation through runoff and associated soil loss. The SAT covers parts of 55 developing
countries, it is the home for over 1.4 billion of whom 550 million are below the poverty line and 70 per
cent of the total poor live in rural areas whose key occupation is agriculture. The SAT is characterized by
high water demand with a mean annual temperature greater than 18 C where rainfall exceeds
evapotranspiration for only 2 to 4.5 months in the dry and 4.5 to 7 months in the wet-dry semi-arid tropics
(Troll, 1965). The coefficient of variation for the annual rainfall ranges between 20 and 30 per cent in
these dry regions.
Along with the erratic rainfall, increasing population, rising demand of water for non-agricultural
uses is proportionally reducing the water availability for agriculture, which is the lifeline for rural poor.
Thus efficient management of rainwater through water harvesting and efficient water use technologies is
the solution for increasing productivity, reducing poverty, and maintaining the natural resource base in the
SAT.
Watershed as a Unit for Efficient Management
Watershed is a logical unit for efficient rainwater management in the dry regions. Along with water other
natural resources such as soil, vegetation, and biota can also be managed efficiently by adopting
integrated watershed management approach.
Based on the impressive successes of on-station watersheds using Vertisol technology for double
cropping on Vertisols, researchers thought that these findings could be “transferred” to farmers’ fields
thereby enhancing the productivity for rainfed systems. The whole process revolved around
“demonstration” of the technology package and possible benefits from the package under farmers’
conditions. The basic assumptions were that:
 all Vertisols faced uniform extent of waterlogging and it could be alleviated by adoption of
broad-bed and furrow (BBF).
 once the benefits of Vertisol technology are demonstrated to the farmers under their situations,
technology will be adopted by the farmers.
Tadannpally village, Medak district in Andhra Pradesh, India functioned as test area for on-farm
watershed trials by scientists of International Crops Research Institute for the Semi-Arid Tropics
(ICRISAT) in collaboration with Andhra Pradesh Agricultural department officials. The approach of onfarm demonstration of technology by the scientists was adopted. The Vertisol technology package as
such including land smoothing, drain construction, BBF system, use of bullock-drawn tropicultor,
summer cultivations, dry seeding and use of appropriate nutrient and pest management options along with
improved high-yielding crop varieties was demonstrated in the village watershed. This improved
watershed was compared with traditional farmers’ system. The trials gave good results (1981-82) which
confirmed that on-farm yields could be similar to those from operational research watersheds where
improved productivity systems with sorghum+pigeonpea intercrop produced best grain yields (1.9 t/ha)
and gave highest net returns of Rs 3838/ha/yr over traditional farmers’ fields which recorded 0.55 t/ha of
grain yield and net returns of Rs 1234/ha/yr. Similar on-farm evaluations were done at different locations
in Maharashtra, Gujarat, Madhya Pradesh, Karnataka and Andhra Pradesh. However subsequent
evaluation of these watersheds after 15 years revealed that in most watersheds farmers went back to their
normal practices and only selected practices were continued. During the watershed evaluation exercise,
hundreds of farmers were interviewed and in addition a multidisciplinary team of scientists also analyzed
the process, farmers’ interviews and possible reasons for the low adoption of the technology package.
Lessons Learnt
Following lessons were learnt from the studies which need to be carefully articulated and implemented
for sustaining the existing agricultural production systems in the SAT. Joshi et al. (1999) identified
following lessons from the earlier experiments.
 Components of Vertisol watershed technology such as placement of seeds and fertilizers,
improved varieties, use of fertilizers and summer cultivation were already known and widely
adopted by the farmers, however, their adoption increased after demonstration.
 The technology was found biased towards large farmers.
 Technology as full package was not adopted by the farmers but different components were
adopted by the farmers
 Several constraints affected the adoption of technology and higher adoption rates were observed
in assured high rainfall Vertisol areas.
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In addition ICRISAT scientists have learnt following lessons over the years working with
watershed technologies (Wani et al. 2001).
1) Learnt efficient technical options to manage natural resources for sustaining systems.
2) Also learnt key processes and institutional lessons such as mere on-farm demonstration of
technologies by the scientists do not guarantee adoption by the farmers.
3) Contractual mode of farmers participation adopted during Vertisol technology evaluation did not
achieve the expected results. There is need to have higher degree of farmers’ participation
through consultative to cooperative mode from planning stage up to evaluation stage.
4) Appropriate technology application domains for region specific constraints need to be identified
and simple broad recommendations do not help eg., Vertisols and BBF.
5) Developmental projects lacked technical support thus technical backstopping is essential. Any
single organization cannot provide answers to all the problems in a watershed; thus, a consortium
of organizations is needed for technical backstopping .
6) Process of partnership selection for each watershed has to be undertaken carefully and
generalized formula-based selection does not guarantee success.
7) Technical change is intimately bound-up with broader institutional context of the watershed and
the role of institutions and different players varies from location to location.
8) Individual farmers should realize tangible economic profits from the watersheds, only then they
come forward to participate in community-based activities in the watershed.
9) Holistic systems approach through convergence of different activities is needed and it should
result in improved livelihood options and not merely soil and water conservation in the
watershed.
10) Technological packages as such are not adopted and farmers adopted specific components that
they found beneficial.
11) No beginning or end to watershed inventions and capacity building for all the stakeholders is
critical and it’s a continuous learning process.
12) Women and youth groups play an important role in decision making in the families.
New Integrated Watershed Management Model for
Efficient Management of Natural Resources
A new model for efficient management of natural resources in the SAT has emerged from the lessons
learnt from long watershed-based research. The important components of the new integrated watershed
management model are:
 Farmer s’participatory approach through cooperation model and not through contractual model.
 Use of new science tools for management and monitoring of watersheds.
 Link on-station and on-farm watersheds.
 A holistic system’s approach to improve livelihoods of people and not merely conservation of soil
and water.
 A consortium of institutions for technical backstopping of the on-farm watersheds
 A micro-watershed within the watershed where farmers conduct strategic research with technical
guidance from the scientists. Minimize free supply of inputs for undertaking evaluation of
technologies.
 Low-cost soil and water conservation measures and structures.
 Amalgamation of traditional knowledge and new knowledge for efficient management of natural
resources
 Emphasize on individual farmer-based conservation measures for increasing productivity of
individual farms along with community-based soil and water conservation measures.
 Continuous monitoring and evaluation by the stakeholders.
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Empowerment of community individuals and strengthening of village institutions for managing
natural watersheds.
Following the new integrated water management model we have initiated new on-farm
benchmark watersheds in India, Thailand, and Vietnam since 1999. All five on-farm and three on-station
watersheds covering varying agroecological, socioeconomic and technological situations are selected and
work is going-on in India, Thailand, and Vietnam. As a case study in this paper one on-farm watershed
i.e., Adarsha watershed at Kothapally, Ranga Reddy district in Andhra Pradesh, India is described here.
In addition, for specific components of the new model examples from other benchmark watersheds are
also described.
Use of New Science Tools for Managing and Monitoring Watersheds
Water Budgeting Using Simulation Models
For prioritization and selection of target regions for watershed development, first order water budgeting
using GIS-linked water balance model is employed. Using GIS linked water balance simulation studies
from monthly rainfall and soils information, the generated outputs could be efficiently used to prioritize
the regions and strategies for efficient management of rainwater management (Fig. 1). Once the target
region is selected then for selecting appropriate benchmark site, second order water budgeting studies
using simulation models are used to identify potential benchmark sites. For selected sites in SAT India,
using WATBAL model (Keig and McAlpine, 1972) and weekly rainfall data of the past 30 years, the soil
water availability and runoff (water surplus) scenario analysis was done (Fig. 2). High rainfall locations
selected were Bhopal, Nagpur, Indore, and Adilabad and scenarios were analyzed. Annual rainfall at these
locations ranged from 1000 to 1200 millimeters and the soils are of high available water-holding capacity
( 200 mm). For these locations the mean water surplus ranged from 270 to 508 millimeters during the
season. Water surplus in 70 per cent of the years (at 30th percentile) ranged from >130 to >270
millimeters across locations. In 50 per cent of the years it was >230 to >475 millimeters indicating
tremendous opportunity to harvest rainfall in surface ponds or to recharge the groundwater.
At the medium rainfall (>700 mm) locations such as Hyderabad, Solapur, Aurangabad, and
Bangalore the mean water surplus ranged from 66 to 187 millimeters annually. The soils in this region are
Alfisols, Vertic Inceptisols, and Vertisols, ranging in available water-holding capacity from 100 to 200
millimeters in the root zone. Considering deep soils at Hyderabad and Solapur the opportunity for water
harvesting exists for 50 per cent of the years or less. However, on low water-holding capacity soils such
as Alfisols it will be possible to harvest water in at least 70 per cent of the years. At Aurangabad and
Bangalore the opportunities for water harvesting are greater as the soils are shallower and of low waterholding capacity. This analysis of water balance indicates the opportunities for harvesting and managing
water in different regions of SAT India to increase crop production from the existing low levels and also
provides information about representative benchmark sites in the target ecoregion.
The CERES family of models has proven to be effective in simulating the water balance of soils
when the drainage is vertical, often an unrealistic assumption. Runoff produced by such models is only
from a point in space and there is no account for the water over space and time. In partnership with
Michigan State University (MSU), USA through an US linkage grant to ICRISAT and the funding
support from Asian Development Bank (ADB) RETA 5812, we have worked on to integrate the
topographic features of the watershed for driving the hydrological models. The automation of terrain
analysis and the use of Digital Elevation Models (DEMs) have made possible to quantify the topographic
attributes of the landscape for hydrologic models. These topographic models, commonly called Digital
Terrain Models (DTMs), partition the landscape into a series of interconnected elements based on the
topographic characteristics of the landscape and are usually coupled to mechanistic soil water balance
model. The partitioning between vertical and lateral movement at a field-scale level will help to predict
the complete soil water balance and consequently the available water for the plants over space and time.
The data generated in the Black Watershed (BW) 7 on-station watershed at ICRISAT was used
for validating the model developed at MSU. This partnership research led to the development of SALUSTERRAE, a DTM for predicting the spatial and temporal variability of soil water balance. A regular grid
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DEM provided the elevation data for TEERRAE. We have successfully applied the SALUS-TERRAE, a
DTM with a functional spatial soil water balance model, at a field scale to simulate the spatial soil water
balance and how the terrain affects the water routing across the landscape. The model provided excellent
results when compared to the field measured soil water content.
Feasibility Studies for Providing Harvested Water for Crop Production
For Akola region, the probabilities of getting 40, 60, 80 and 100 millimeters water for supplemental
irrigation from the runoff harvesting structure using simulation is shown in Figure 3. The probabilities of
getting water for irrigation from the tank are high for most part of the crop growing season. However, the
high probability of getting 100 millimeters irrigation water was limited to only 3 months namely
September, October and November. High runoff, and low seepage loss are the main reasons for adequate
availability of water in the harvesting structure. The 10 years mean cumulative water outflow from the
runoff harvesting structure indicated a possibility of increasing the size of structure since approximately
2200 m3 runoff water overflows from the structure every year. Overall the analysis indicated a good
prospect of runoff water harvesting in Akola region.
Crop Simulation Models for Identifying the Constraints and Yield Gap Analysis
We have validated the Decision Support System for Agricultural Technology (DSSAT) model for
CROPGRO-soybean and CROPGRO-chickpea using the data sets generated from on-station watershed at
Patancheru. The validated models were used for estimating the potential soybean-chickpea system’s
yields in the target ecoregion using the historical weather data sets for estimating the yield gaps. The
soybean model along with historical weather records of the past 22 years from Patancheru was
successfully used to evaluate the effect of soil depth on soybean yields. By determining the non-linear
yield-soil depth relationship over the 22 years it was observed that at Patancheru even during the normal
rainfall year soybean cannot be grown in a soil with a soil depth less than 37.5 centimeters. Further the
studies, revealed that 70 per cent of the years soybean-chickpea system’s productivity at Patancheru could
be 3.5 t/ha on medium depth soil and 3.0 t/ha on shallow (<50 cm) depth soil.
Crop simulation models using scenario analysis for yield gap and constraint identification provide
an opportunity to simulate the crop yields in a given climate and soil environment. ICRISAT researchers
have adopted DSSAT v 3.0, a soybean crop growth model to simulate the potential yields of soybean crop
in Vertisols grown at different benchmark locations. Mean simulated yield obtained for a location was
compared with the mean observed yield of the last five years to calculate the yield gap. The results (Table
1) showed that there is a considerable potential to bridge the yield gap between the actual and potential
yield through adoption of improved resource management technologies. Such scenario analysis helps the
researchers to identify the high potential areas where large yield gaps existed and considerable gains in
productivity could be achieved.
Economic Evaluation of Tank Irrigation Systems
The economic evaluation of tank irrigation for high rainfall Vertisol areas has been carried out using a
simulation model (Pandey, 1986). The model consisted of several component modules for rainfall, runoff,
soil moisture, and yield response to irrigation and tank- water-balance. Simulations were run for three
different seepage rates namely 0, 10, 20 millimeters per day for a test site on a Vertisol in central India
(Madhya Pradesh). Results obtained from the simulation indicate that as seepage rate increases, optimal
tank size increases while optimal size of the command area, other factors such as runoff volume and
availability of irrigable land become constraints. Taking the most common cropping system of the region,
it was found that tanks are quite attractive for the soybean-wheat cropping pattern even at seepage rates as
high as 20 millimeters per day. With the soybean+pigeonpea intercrop, the tank is profitable at seepage
rates less than 10 millimeters per day.
Linking On-station Strategic Research with On-farm Watersheds
The operational scale watersheds at ICRISAT are in operation since 1976 aimed at increased productivity,
and improved soil quality through integrated watershed approach as a logical unit to harvest rainwater for
increased productivity and ground water recharge. ICRISAT initiated watershed research to address the
problems of low productivity of Vertisols irrespective of their high potential to produce. The technology
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package consisting of summer cultivation, broad-bed and furrow (BBF) to take out excess rainwater
safely out of field, dry planting, grassed waterways, use of improved bullock-drawn tropicultor for field
operations, improved stress-tolerant crop varieties, appropriate nutrient and pest management options
showed very promising results.
Improved vs Conventional Systems – Vertisol Watershed
In an improved system with all the above-said environment-friendly options, the average productivity was
4.7 t/ha and this improved system had a carrying capacity of 18 persons/ha/yr, whereas the traditional
system with farmer adapted practices could give a productivity of only about 0.9 t/ha and a carrying
capacity of this land is only 4 persons/ha/yr (Fig. 4). Along with this improved productivity the improved
system could also sequester more carbon (0.335 t/ha/yr) along with improvement in soil quality (Wani et
al., 2000). Most importantly in the improved system 67 per cent of the rainfall was used by the crops, 14
per cent of the rainfall was lost as runoff and 19 per cent as evaporation and deep percolation whereas in
the traditional system only 30 per cent of the total rainfall was used by the crops, 25 per cent was lost as
runoff and 45 per cent as soil evaporation and deep percolation. The soil loss in improved system was
only 1.5 t/ha compared to traditional system where the soil loss was 6.4 t/ha.
Increased ProductivityVertic Inceptisols Watershed
At ICRISAT, Patancheru, studies on crop productivity and resource use of a soybean-chickpea sequential
and soybean+pigeonpea intercrop systems on two landforms (BBF and flat) and two soil depths (shallow
and medium-deep) at watershed scale on a Vertic Inceptisol were taken up. The results show that the
improved BBF system recorded an average of 0.1 t/ha more productivity than the flat landform during
1995-2000. During 2000-2001, when rainfall recorded was 958 millimeters (31 per cent above normal
rainfall), the BBF system yielded 500 kilograms more grains in case of soybean-chickpea sequential
system than that of the flat land form treatment. Similarly increased crop yield of 2.9 t/ha of soybean
intercropped with pigeonpea on BBF was recorded to that of 2.63 t/ha in flat landform treatment. Total
runoff was higher in the flat land system (23% of the seasonal rainfall) than on the improved system (15%
of the seasonal rainfall). The BBF had more deep drainage than flat land system especially for the shallow
soil. The runoff was found to be more in flat land system (190 mm), with a peak runoff rate (0.096
m3/s/ha) compared to BBF system where runoff is comparatively less (150 mm) with a low peak runoff
rate (0.086 m3/s/ha). The BBF system was found to be useful in decreasing runoff and increasing rainfall
infiltration. The soil loss in flat land system was more (2.2 t/ha) and low (1.2 t/ha) in BBF system.
These studies clearly demonstrated the potential of Vertisols and Vertic Inceptisols with 800
millimeters annual average rainfall at watershed level. Using the concept of potential yield using crop
simulation studies and operational scale watershed plots showed that potential yields could be achieved at
field scale following appropriate soil, water, crop nutrient, and pest management options.
Response of Crops to Supplemental Irrigation
Following efficient rainwater management the harvested rainwater need to be used efficiently for
increasing system’s productivity. Efficient use of rainwater by using of as supplemental source during the
stress period was evaluated at ICRISAT and other research stations in India.
Benefits of supplemental irrigation in terms of increasing and stabilizing crop production have
been impressive even to dependable rainfall areas of both Alfisols and Vertisols (Pathak and Laryea,
1991; El-Swaify et. al. 1985; Singh et. al. 1998; Oswal 1994; Vijayalakshmi 1987). As shown in Table 2,
good yield responses to supplemental irrigation were obtained on Alfisols in both rainy and post-rainy
seasons. The average water application efficiency, WAE (ratio of increase in yield to depth of water
applied) varied with crops e.g., for sorghum 14.9 kg mm/ha and for pearl millet 8.8 to 10.2 kg mm/ha.
Tomatoes responded very well to water application with an average WAE of 186.3 kg mm/ha. In the
sorghum+pigeonpea intercrop, two irrigations of 40 millimeters each, gave an additional gross return of
Rs 3950/ha. The largest additional gross return from the supplemental irrigation was obtained by growing
tomato (Rs 13870/ha).
On Vertisols, it was found that the average additional gross returns due to supplemental irrigation
were about Rs 830 per ha for safflower, Rs 2400/ha for chickpea and Rs 3720/ha for chillies. The average
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WAE was largest for chickpea 5.6 kg mm/ha followed by chillies 5.3 kg mm/ha and safflower 2.1 kg
mm/ha.
Farmers’ Participartory Approach: Selection of Watershed, prioritization and Execution
of Works
Adoption of integrated watershed management on-farm is possible through community initiatives and
strength of local participation. People’s participation in planning, developing and executing the watershed
activities is indispensable.
ICRISAT, Drought Prone Area Project (DPAP) officials, non-governmental organizations
(NGOs) and farmers visited three priority villages in the targeted Ranga Reddy district in Andhra
Pradesh. The consortium partners jointly selected Kothapally watershed for participatory on-farm
watershed as the village had not a single tank for community use, maximum area was under rainfed crops
and the crop yields were lower (1 to 1.5 t/ha). Moreover, during the initial visit and subsequent
reconnaissance survey farmers showed keen interest to participate in the watershed program. The Gram
Sabha involving all the villagers ratified the decision for selecting the watershed and agreed to take active
part in the watershed programs. Subsequently, planning and execution of various watershed works was
done by the villagers committees, self-help groups and users groups.
Micro-watershed Development as an Island for Testing Technology: Evaluation and
Monitoring
Within a watershed of 470 ha, a micro-watershed of 30 ha is delineated, developed and monitored for
quantifying the impact of watershed developments on runoff, soil loss and nutrient losses. Developed
micro-watershed and undeveloped micro-watersheds are fully instrumented with automatic runoff
recording and sediment loss gauging stations. In addition, raingauges are fixed across the watershed to
measure the rainfall variation in the watershed. In a micro-watershed farmers conduct simple trials to
compare improved crop varieties, landform treatments, balanced nutrient schedules, integrated pest
management and nutrient management options, etc. Farmers are provided technical support and no inputs
are provided free of cost for evaluating technologies. Farmers have conducted several trials comparing
improved landform treatments such as BBF and contour planting using improved bullock-drawn
tropicultor vs. normal practice of sowing crops with their traditional wooden plough, balanced
fertilization, and various improved crop management options mentioned above. However, field
experimentation by the farmers does not remain confined to the micro-watershed and large number of
farmers conduct trials within the watershed.
Increased Productivities with Improved Management Practices at Kothapally Watershed
At Kothapally, along with all the improved practices discussed, farmers evaluated improved management
practices such as sowing on a BBF landform, flat sowing on contour, and fertilizer application, nutrient
management treatment along with Rhizobium or Azospirillum sp. inoculations and using improved
bullock drawn tropicultor for sowing and interculture operations. Farmers obtained two-fold increase in
the yields in 1999 (3.3 t/ha) and three-fold increase in 2000 (4.2 t/ha) as compared to the yields of sole
maize (1.5 t/ha) in 1998 (Table 3). In case of intercropped maize with pigeonpea improved practices gave
a four fold increased maize yield (2.7 t/ha) compared with farmers practices where the yields were 0.7
t/ ha. In case of sole sorghum the improved practices adopted increased yields by three-fold within one
year. In 1999-2000, farmers achieved highest systems productivity, total income and profit from
improved maize-pigeonpea and improved sorghum-pigeonpea intercropping systems (Table 4). Along
with the highest systems productivity the cost-benefit ratio of the improved systems was more (1:3.47)
compared to the farmers traditional cotton-based systems (Wani 2000). In 2000–2001, several farmers
evaluated BBF and flat landform treatments for shallow and medium depth black soils using different
crop combinations. Farmers harvested 250 kilograms more pigeonpea and 50 kilograms more maize per
hectare using BBF on medium depth soils than the flat landform treatment. Furthermore, even on flat
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landform treatment farmers harvested 3.6 tonnes maize and pigeonpea using improved management
options as that of 1.72 tonnes maize and pigeonpea grains using their normal cultivation practices (Table
5). Similar benefits from improved BBF landform and also improved management options were reported
by the farmers with shallow soils and with other cropping systems. The rainfall during 1999 in this area
was 559 millimeters, which was 30 per cent below normal rainfall, and in 2000 the rainfall was 958
millimeters, which was 31 per cent above normal. In spite of this variation in rainfall received in 1999 and
2000 (Tables 3, 4 and 5) the productivity of the crops marked a sustainable increase during 1999-2000
and 2000-2001.
Nutrient Budgeting ApproachBoron and Sulphur Amendments
At Lalatora watershed, detail characterization of soils in this watershed revealed that these soils are
deficient in boron (B) and sulphur (S) and both these nutrients are critical for optimizing productivity of
soybean-based systems. Farmers were made aware of the results and some farmers came forward to
evaluate the response of boron and sulphur application in their fields along with the improved
management options. Ten kilograms of borax (1 kg B) and 200 kg/ha of gypsum (30 kg S) were applied
by the farmers, the treatments studied are - best-bet treatment (control), boron application, sulphur
application, and B+S application. In 2000, all the farmers reported significant differences in soybean plant
growth with B, S, and B+S treatments over the control treatment. Finally at the harvest soybean yields
were increased by 19 to 25 per cent over the best-bet control treatment (Table 6). Soybean yields in case
of control were 1.52 t/ha that is 18 per cent more than the 1999 best-bet treatment yield of 1.28 t/ha. The
results indicated that amendments with B and S not only increased soybean yields over best-bet treatment
but also benefited the subsequent wheat crop without further application of B and S. The residual benefits
of B and S amendments were to the tune of 31 to 40.6 per cent over the best-bet (control) treatment in
case of following wheat crop. Soybean followed by wheat system’s productivity was increased by 27 to
34 per cent over the best-bet treatment which served as control for this experiment. Farmers were so much
impressed with their experimentation that for 2001 season they indented the B and S for their use well in
advance through the NGO, the BAIF Research Foundation. Looking at the results of experiments
conducted by the farmers in Lalatora sub-watershed the farmers in other sub-watersheds of Milli
Watershed have come forward to conduct these experiments in their fields during 2001 rainy season.
Consortium Approach for Technical Backstopping
A Consortium of various institutes and organizations as depicted in the Figure 5 provides technical
support to each on-farm benchmark watershed.
Empowering the Stakeholders through Training
Farmers are exposed to new methods and technologies for managing natural resources through training
and field visits to on-station and other on-farm watersheds. Farmers and landless families were trained
and encouraged to undertake income generating activities in the watershed which can be of help to sustain
the productivity at watershed level. Various training sessions were held for farmers on improved
management options like providing training on farm operating implements; integrated pest management
(IPM) and integrated nutrient management (INM) options. Along with the farmers, the key change agents
like watershed committee members; agriculture and extension officials were trained at ICRISAT on
different aspects of integrated watershed management. Special emphasis is given to educate and increase
awareness on new management options to the women farmers to new management options as women
play a key role in adoption of a new technology. Women in greater number were trained in
vermicomposting technology at Kothapally. Educated youth were trained in skilled activities like nuclear
polyhedrosis virus (NPV) production and vermicomposting, which helped them in generating incomes.
Continuous Monitoring and Evaluation
To know the impact of watershed management continuous monitoring and impact assessment was done.
 Weather: An automatic weather station is installed to continuously monitor the weather
parameters.
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Groundwater: To monitor the groundwater levels, open wells in the watershed are geo-referenced
and regular monitoring of water levels is done by the watershed committee secretary.
Hydrological investigations of the existing wells in the watershed indicated a rise in groundwater
table levels (5-6 m) at Kothapally (Figs. 6a and 6b).
Runoff and soil loss: Runoff, soil and nutrient losses are monitored using automatic water level
recorders and sediment samplers and the runoff as a per cent of the seasonal rainfall was observed
to be 7 per cent in the undeveloped watershed and 0.6 per cent in a developed watershed where
soil and water conservation measures like gully plugging and bunding were adopted.
Pest monitoring: Pheromone traps were installed to monitor Helicoverpa populations and
appropriate pest control measures are taken up.
Crop productivities: Productivities are recorded for each crop every year as described in the
previous sections and impact is assessed and increased yields, increased productivities and
increased incomes were observed from 1999 to 2001.
Nutrient budgeting: Studies were conducted on optimum doses of fertilizers to have balanced
nutrient budgets. Quantification of BNF in farmers’ fields using N difference method and 15N
isotope dilution method.
Satellite monitoring: Changes in cropping intensity, greenery, water bodies and ground water
levels are monitored, GIS maps indicating soil types, soil depths, crops grown during rainy and
post rainy season have been prepared.
Emerging Issues
Despite greater adoption of integrated watershed approach for water harvesting and efficient use of
natural resources certain important issues need to be addressed as they have a bearing on sustainable
production in the semi arid tropics. Research issues need to be addressed for collective action and gender
related issues for adopting technologies in the watershed framework. These issues are equally important
as the technical and economic factors. In the past on-farm watershed works very little attention was given
to farmers participation, community action, group formation and empowerment of farmers. This has
resulted in very low adoption as well as sustainability of many watershed technologies. Some emerging
issues are:
 No starting and end point for watershed activity and continuous training of the farmers and
community need to be sustained.
 How to institutionalize technical backstopping for the watersheds?
 How to harmonize existing village institutions with watershed committees and self-help groups
and increase their efficiency?
 Policy options for ground water harvesting; issues like borewells, use of working strategies and
maintenance.
 Sustainable management of watershed strengthening of village institutions, policies and increased
awareness of communities need to be achieved.
 Need to study on-site and off-site impacts of watershed development programs.
Conclusion
An in-depth understanding of the SAT scenario under farming systems reveal that community
participation, capacity building at local level through technical backstopping by a consortium of the
organizations and use of high-science tools to manage the watershed efficiently form the key elements in
managing rain water efficiently. In order to sustain the productivity in the SAT, a holistic approach of
integrated watershed management need to be scaled-up through appropriate policy and institutional
support and its on-site and off-site impacts need to be studied.
9
Acknowledgements
The financial assistance provided by the Asian Development Bank through RETA 5812 is gratefully
acknowledged. The efforts of staff of DPAP, BAIF, CRIDA and MV Foundation are greatly appreciated.
At all the benchmark sites, team of scientists from NARS and ICRISAT are involved in undertaking
research and their efforts are also acknowledged. The contribution from farmers who are the important
partners is greatly acknowledged. We thank Dr. K.V. Padmaja and Dr. K. Sailaja for their help in
preparing this document.
10
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under rainfed conditions in the semi-arid tropics. Advances in Soil Science 1:1-64.
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Pathak, P.; Laryea, K.B.; and Sudi, R. 1989. A runoff model for small watersheds in the semi-arid tropics.
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Singh, A.K.; Kumar, Ashok; and Singh, K.D. 1998. Impact of rainwater harvesting and recycling on crop
productivity in semi-arid areas – a review. Agriculture Review 19(1):6-10.
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Jusatz, H. Berlin: Springerverlag Publishers.
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Hawaii.
Vijayalakshmi, K. 1987. Soil management for increasing productivity in semi arid red soils: Physical
aspect. Alfisols in the semi-arid tropics. Proceedings of the Consultants Workshop on the State of the
Art and Management Alternatives for Optimizing the Productivity of SAT Alfisols and Related Soils,
1-3 December 1983, ICRISAT, Patancheru, India.
Wani, S.P. 2000. Integrated watershed management for sustaining crop productivity and Reduced soil
erosion in Asia. Paper presented at MSEC Meeting, 5–11 November 2000, Semarang, Indonesia.
Wani, S.P.; Sreedevi, T.K.; Pathak, P.; Piara Singh; and Singh, H.P. 2001. Integrated watershed
management through a consortium approach for sustaining productivity of rainfed areas: Adarsha
watershed, Kothapally, A.P.—a case study. Paper presented at Brainstorming Workshop on Policy
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11
Table 1. Simulated soybean yields and yield gap for the selected locations in India.
Location
Mean
sowing
date
Mean
harvest
date
Simulated yields (t/ha)
Mean
Mean observed
yield1 (t/ha)
Yield gap (t./ha)
SD
Primary zone
Raisen
Betul
Guna
Bhopal
Indore
Kota
Wardha
22-Jun
19-Jun
30-Jun
16-Jun
22-Jun
3-Jul
17-Jun
11-Oct
8-Oct
14-Oct
8-Oct
10-Oct
16-Oct
6-Oct
3.051
2.371
1.695
2.310
2.305
1.249
2.997
1.278
0.636
1.957
0.615
0.980
0.979
0.653
-
-
0.858
0.840
1.000
1.122
1.014
1.042
1.513
0.855
1.310
1.183
0.235
1.955
Secondary zone
Jabalpur
Amaravathi
Belgaum
23-Jun
18-Jun
17-Jun
11-Oct
8-Oct
30-Sep
2.242
1.618
1.991
0.480
0.738
0.661
0.896
0.942
0.570
1.346
0.676
1.421
20-Jun
5-Oct
2.700
0.689
-
-
20-Jun
5-Oct
2.664
0.705
-
-
Tertiary zone
Hyderabad
(shallow soil)
Hyderabad
(medium-deep soil)
1. Mean of reported yields of last five years.
12
Table 2. Grain yield response (t/ha) of cropping systems to supplemental irrigation on an
Alfisol watershed, ICRISAT Center.
One irrigation
of 40 mm
Increase
due to
irrigation
WAE* Two irrigations Increase due WAE* (kg Combined
(kg mm1 of 40 mm each to irrigation mm1 ha-1) WAE (kg
ha-1)
mm1 ha-1)
Intercropping System
Pearl millet
Pigeonpea
-----------------------------------------------------------------------------2.353
0.403
10
1.197
0.423
5.3
6.8
Sorghum
Pigeonpea
-----------------------------------------------------------------------------3.155
0.595
14.9
1.22
0.535
6.7
9.4
5.3
6.9
186.3
127.1
Pearl millet
Sequential cropping system
Cowpea
----------------------------------------------------------------------------2.577
0.407
10.2
0.735
0.425
Pearl millet
Tomato
----------------------------------------------------------------------------2.215
0.35
8.8
26.25
14.9
*Water application efficiency (WAE) = Increase in yield due to water application
Depth of irrigation
13
Table 3. Average crop yields from on-farm evaluation of improved
technologies in Adarsha watershed, Kothapally, 1998, 1999 and 2000.
Crop
1998 baseline
Sole maize
Intercropped maize
(Farmers’ practice)
Intercrop pigeonpea
(Farmers’ practice)
1.50
-
Sole sorghum
Intercropped sorghum
1.07
-
0.19
Yield (t/ha)
1999
3.25
2.70
0.70
0.64
0.20
2000
3.75
2.79
1.60
0.94
0.18
3.05
1.77
3.17
1.94
Table 4. Total productivity, cost of cultivation for different crops at Kothapally
watershed during crop season 1999-2000.
Cropping systems
Maize/pigeonpea
(Improved)
Sorghum/pigeonpea
(Improved)
Cotton
(Traditional)
Sorghum/pigeonpea
(Traditional)
Greengram
(Traditional)
Total
productivity
Cost of
cultivation
(t/ha)
(Rs. ha-1)
(Rs. ha-1)
3.3
5900
20500
14600
01:03.5
1.57
6000
15100
9100
01:02.5
0.9
13250
20000
6750
01:01.5
0.9
4900
10700
5800
01:02.2
0.6
4700
9000
4300
01:01.9
14
Total Profit (Rs. C:B ratio
income
ha-1)
Table 5. Productivities in different on-farm trails at Kothapally during 2000-2001.
System
Soils
Maize/PP
Maize/PP
Maize/PP
Maize/PP
Sorghum
Maize/PP
Sorghum/PP
Sorghum
Landform
Yield (t/ha)
(1)
1.750
1.680
2.830
2.780
3.000
1.490
0.470
1.010
Shallow
BBF
Shallow
Flat
Medium
BBF
Medium
Flat
Medium
BBF
(Local farmers practice)
(Local farmers practice)
(Local farmers practice)
Total systems
productivity
(2)
0.380
0.290
1.070
0.820
0.220
0.115
-
(1+ 2)
2.130
1.970
3.900
3.600
3.000
1.710
0.590
1.010
1. Main crop (Maize/Sorghum)
2. Component crop (Pigeonpea)
Table 6. On-farm evaluation of response of soybean and wheat to boron
and sulphur amendments in Lalatora sub-watershed, rainy season 2000.
Grain yield (t/ha)
Treatment
Boron
Sulphur
Boron + Sulphur
Control (best-bet treatment)
Soybean
Wheat
Soybean
wheat system
3.74 (40.6)
5.61 (34.2)
3.5 (31.9)
5.31 (27.0)
1.87 (23.2)1
1.81 (19.1)
1.91 (25.6)
3.57 (34.2)
5.48 (31.1)
1.52
2.66
4.18
1. Figures in parenthesis are per cent increase over control (best-bet treatment).
15
16
Rainfall(mm), PE(mm)
600
500
RF
Hyderabad
PE
Lat 17 27' Long 78 28'
o
o
400
300
200
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Rainfall(mm), PE(mm)
600
500
Bhopal
o
RF
o
PE
Lat 23 16' Long 77 25'
400
300
200
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Rainfall(mm), PE(mm)
600
500
Solapur
o
RF
o
Lat 17 40' Long 75 54'
PE
400
300
200
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Rainfall(mm), PE(mm)
600
500
Banglore
o
RF
o
Lat 12 58' Long 77 48'
PE
400
300
200
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Figure 2 Rainfall and pan evaporation analysis for selected sites in SAT India
100
40 mm
60 mm
80 mm
100 mm
Probability %
80
60
40
20
0
J
J
A
S
O
N
D
J
F
M
A
M
Months
Figure 1. Probabilities of obtaining 40, 60, 80, and
100
mm of water
for and
irrigation
from
tank
at Akola
Figure 3. Probabilities
of obtaining
40, 60, 80,
100 mm of
watera for
irrigation
from a tank at Akola
(based data).
on 10 years simulated data).
(based on 10 years simulated
19
7
Observed potential yield
6
Grain yield (t ha-1 )
5
A
Carrying capacity
18 persons ha-1
Rate of growth
78 kg ha-1 y-1
4
3
Trend line
Carrying capacity
4 persons ha-1
2
1
Rate of growth
26 kg ha-1 y-1
B
Sorghum
0
1977 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 2001
Year
Three year moving average of grain yield under (A) improved and (B) traditional
technologies on Vertisol watershed at ICRISAT (1977-2001)
Figure 4. Three year moving average of grain yield under improved (A) and traditional (B) technologies
on a Vertisol watershed at ICRISAT (1977–2001).
20
Figure 5
21
Effect of check-dam on groundwater recharge in
Adarsha watershed, Kothapally
17/07/2K
18/08/2K
20/09/2K
18/10/2K
13/11/2K
Water level in well (m)
0
3
6
9
Near check-dam
Away from check-dam
Figure 6a. Groundwater levels before construction of checkdam at Kothapally during 1999.
Groundwater level before check-dam construction in Adarsha
watershed, Kothapally
29/07/99
08/08/99
23/08/99
04/09/99
20/09/99
Water level in well (m)
0
3
6
9
Near check-dam
Away from check-dam
Figure 6b. Effect of checkdam on groundwater levels at Kothapally during 2000.
22