impact of subsurface drainage on land quality, groundwater quality and crops yields in haryana ...

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IMPACT OF SUBSURFACE DRAINAGE ON LAND
QUALITY, GROUNDWATER QUALITY AND CROPS
YIELDS IN HARYANA
THESIS
SUBMITTED IN FULFILMENT OF REQUIREMENTS
FOR THE AWARD OF THE DEGREE OF
DOCTOR OF PHILOSOPHY
IN
CIVIL ENGINEERING
BY
MOHAN LAL
Reg. No. 2K04- NITK-Ph.D-1005
CIVIL ENGINEERING DEPARTMENT
NATIONAL INSTITUTE OF TECHNOLOGY
KURUKSHETRA-136119
APRIL, 2011
IMPACT OF SUBSURFACE DRAINAGE ON LAND
QUALITY, GROUNDWATER QUALITY AND CROPS
YIELDS IN HARYANA
A
THESIS
SUBMITTED IN FULFILMENT OF REQUIREMENTS
FOR THE AWARD OF THE DEGREE OF
DOCTOR OF PHILOSOPHY
IN
CIVIL ENGINEERING
BY
MOHAN LAL
UNDER THE GUIDANCE OF
Dr. S. K. Gupta Dr. V. K. Arora
Project Coordinator Professor
All India Coordinated Research Projects Civil Engineering Department
Central Soil Salinity Research Institute National Institute of Technology
KamaM32001 Kurukshetra-136 119
Vi ^f^^^^ "^3tgT ^J
CIVIL ENGINEERING DEPARTMENT
NATIONAL INSTITUTE OF TECHNOLOGY
KURUKSHETRA-136119
APRIL, 2011
dedicated ta
M^SpinituaiQwai
Sa, Manehcvc Muni Ji Mahanaj
CERTIFICATE
This is to certify that the thesis entitled "IMPACT OF SUBSURFACE DRAINAGE
ON LAND QUALITY, GROUNDWATER QUALITY AND CROPS YIELDS IN
HARYANA" being submitted by Sh. Mohan Lai (Registration'No.2K04-NlTK-Ph.D-l 005) to
the Faculty of Civil Engineering, National Institute of Technology, Kurukshetra for the award
of Degree of DOCTOR OF PHILOSOPHY in Civil Engineering, is a bonafide research work
carried out by him under the joint supervision and guidance of the undersigned. His thesis has
reached the standard of fulfilling the requirements of the regulations related to the degree.
The contents of this thesis have not been submitted in part or in full to any other
University for the award of any Degree or Diploma.
(Dr. S. K. Gupta)
>r.'
Project Coordinator
Professor
AH India Coordinated Research Project (AICRP)
Civil Engineering Department
Central Soil Salinity Research Institute
National Institute of Technology
Karnal-132001
Kurukshetra-136 119
CANDIDATE'S DECLARATION
1 hereby certify that the work which is being presented in the thesis, entitled
"IMPACT OF SUBSURFACE DRAINAGE ON LAND QUALITY, GROUNDWATER
QUALITY AND CROPS YIELDS [N HARYANA", in the fulfilment of the requirements
for the award of the degree of Doctor of Philosophy and submitted in the Civil Engineering
Department, National Institute of Technology, Kurukshetra, is an authentic record of my own
work carried out under the supervision of Dr. V.K. Arora, Professor, Civil Engineering
Department, National Institute of Technology , Kurukshetra (Haryana), India and Dr. S. K.
Gupta. Project Coordinator, All India Coordinated Research Project, Central Soil Salinity
Research Institute, Kamal (Haryana), India
The material presented in this thesis has not been submitted by me for the award of
any degree of this or any other University/Institute.
Date: 6/o//i*/^ (MOHAN LAL)
J;
u
CANDIDATE'S DECLARATION
I hereby certify that the work which is being presented in the thesis, entitled
"IMPACT OF SUBSURFACE DRAINAGE ON LAND QUALITY, GROUNDWATER
QUALITY AND CROPS YIELD^IN HARYANA", in the fulfilment of the requirements for
the award of the degree of Doctor of Philosophy and submitted in the Civil Engineering
Department, National Institute of Technology, Kurukshetra, is an authentic record of my own
work carried out under the supervision of Dr. V.K. Arora, Professor, Civil Engineering
Department, National Institute of Technology , Kurukshetra (Haryana), India and Dr. S. K.
Gupta. Project Coordinator, All India Coordinated Research Project, Central Soil Salinity
Research Institute, Karaal (Haryana), India
The material presented in this thesis has not been submitted by me for the award of
any degree of this or any other University/Institute.
Date: ejOIJM:^,
(MOHAN LAL)
n
ABSTRACT
India is endowed with vast resources of arable land and water, which are favourable
for the agricultural development. On the other hand, sustainability of irrigated agriculture has
been questioned at many forums because introduction of irrigation is accompanied by rise in
water table and soil salinization. As per the latest estimate 6.73 million ha area is affected by
soil salinity including alkalinity (Mandal et al, 2010). In Haryana alone, an area of 476,000
ha in 1998 was under threat already having water table within 2 m depth while certain other
areas had rising trend in the water .table. It is now established that to sustain irrigated
agriculture, development of an efficient irrigation system with an appropriate drainage
infrastructure is essential.
Subsurface drainage (SSD) system design, performance evaluation and transfer of
technology, therefore, have been the thrust areas of research in the country/Haryana.
Although, few studies at the experimental and farm level show that the technology is
financially and socially feasible, general guidelines on many aspects are unavailable for field
practitioner to easily adopt this technology. It is with this background that current study was
undertaken in a subsurface drainage project at Jhajjar (Haryana) with the objectives: (i) to
develop drainage investigation guidelines for assessing the need for subsurface drainage; (ii)
to develop drainage design, material testing and construction guidelines to implement an
effective subsurface drainage; (iii) to monitor and evaluate the hydraulic performance and
assess the impact of subsurface drainage on land, water quality, crop productivity and
material performance; (iv) to assess the performance of pump-cum-gravity outlet; (v) to
document socio-economic issues for land drainage activities in Haryana; (vi) to apply Model
(WaSim) to assess water management options in drained lands; and (vii) to develop and
propose general guidelines for fiature SSD works in Haryana.
Four blocks covering an area of about 210 ha were designed and monitored for this
study out of a total of 805 ha put under subsurface drainage in Beri block of the Jhajjar
district in Haryana.
Most drainage design parameters such as drain depth, lateral drain spacing and drain
diameters for laterals and collectors were fixed beforehand as per the past experience.
Nonetheless, design evaluations were made to ensure lengths/area drained by
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laterals/collectors of various diameters are within the maximum permissible lengths/area
drained. It was observed that to keep the depth of the collectors within 3 m, lateral depth at
no point should exceed 2 m below the groimd surface.
Studies were conducted to evolve appropriate guidelines on filter requirement,
material testing and construction. Soil particle size analysis curve gave a good indication of
the sedimentation in drain pipes and need for a envelop (filter). The PVC pipes were tested
for visual, dimensional (diameter, length, perforations, weight) and physical tests (stiffiiess,
elongation, bending, impact and acetone). Adopting strict test procedure as per ISI
9271:2004 and Deutsche Industrie Norm (DIN) would be sufficient to assess the suitability
of the pipe materials. Field tests revealed that laterals of 80/100 mm PVC pipes pre-wrapped
with polypropylene non-woven fibres >3.0 mm thick and apparent opening size (09o)> 300
microns performed well. Filter with 60 mesh opemng was found to be appropriate for
collector. Re-excavation of pipes after two and six years revealed that drains with envelope
as per these guidelines performed well as the sediments observed in the manhole/sump and
drains were within permissible limits (<1 cm).
The current installation in Jhajjar project (primary data) were also used to prepare
drainage construction guidelines. It emerged that construction infrastructure needs to be
supported by few indigenous machines such as an excavator, backhoe loader (JCB) and a
bulldozer together with the tractors and trailers and pick up vans. A filter-wrapping machine
is mandatory for large-scale projects. With such a set-up, regional development and rural
employment opportunities are imminent.
Sump and manholes of reinforced cement concrete (RCC) with an internal diameter
of 1.2 and 0.9 m, respectively, with a fixed base plate at one end of the pipe could be a good
alternative for easy and speedy installation in highly waterlogged condition. However, it was
seen that the bottom hole in the sump from where the collector pipe enters the sump should
be around 10 cm below the designed collector pipe level. It would allow the connection to
always go down into the sump. Experience revealed that when collectors were installed under
wet conditions (high water table), a perforated collector would ease the installation process.
It was also observed that it is always better to install the collector over its full length without
bothering about the installation of the manholes (except when there are bends). While the
installation is in progress, pumping at the sump should be continued so that the trench would
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be a lot drier when one comes back to install the manholes and the laterals. Pumping for 24
hours a couple of days will do the job.
The main construction problems encountered during the installation of the sump and
manholes, as well as during connections of the drainpipes in the manholes or the sump were
forming of slush that makes the soil under the structure unstable, pushing up of the pipe due
to unstable conditions and the soil wall collapse that pushed the structure or pipe out of
position or pushed the pipe section over. A solution to avoid/ minimize some of the problems
was to reduce the depth of the system, so that the depth of the laterals does not go deeper
than 2.0 m at any point. As such, the collector pipes wherever possible should be laid at a
depth of 2.75 m instead of 3.0 m.
A study was conducted for a period of more than two years to assess the machine time
lost. Nearly 50% of the machine time was lost in organizational problems (28%) and losses
in repair and maintenance (15%). These losses could be reduced with proper planning.
Conflict resolution with farmers (to allow trencher in standing crops) resulted sometimes in a
loss of 50-75% of the day.
The block wise pumped water volumes revealed that pumping was not carried out
imiformly in the four blocks being maximum in block J15 and minimum in J16. It emerged
that pumping needs to be enhanced to achieve better performance from the drainage system.
The EC2 (0-30 cm) contours revealed overall decline in soil salinity indicating that the
process of reclamation has become operative in the drainage blocks upon introduction of
subsurface drainage. Contrarily monitoring of an adjoining area, where no subsurface
drainage system was installed continued to have high soil salinity with ±1 unit from its initial
values. The analysis of water quality showed a decreasing trend after installation of SSD. It is
fair to assume that drainage effluents could be used for irrigation after one/two years of
operation.
The overall impact of SSD was evaluated by analyzing the crop yield data which
showed that wheat yield increased by 88.5% and paddy yield increased by 38.2% due to
decrease in soil salinity and proper water table maintenance.
The performance of a gravity-cum-pumped outlet was obtained theoretically, which
revealed that during the year nearly 101.6 to 502.7 m /day with an average of 215.7 m /day
effluent could be removed through gravity while volume drained through pump could be 288
mVday. As such, water removed through gravity would result in a cost saving of 75%.
Socio-economic studies revealed that the majority (83.82%) of the farmers are
marginal having land holding less than 1 ha. Family composition revealed that 87.5% of the
household have the family size in between 1 to 8 members and 25% of the household have
members up to 4. The occupational status of the selected households revealed that 69.47% of
the family members were workers and 30.53% dependents. Since the expansion and efficient
application of intervention in rural setting depends upon the educational status of the village,
survey on educational status revealed that 50.71% of the members of the total selected
household are literate. Farm assets and capital inventory study revealed that total average
value of fixed assets of the selected farms was ? 110865.00 per farm. The total annual family
income from all the sources was ? 32619.00, 46.90% income being from crop enterprises,
26.74% from livestock and 26.22% from services and 0.14% from hiring out of labour. The
total cost of production excluding rental value of the land was the lowest in 2004-05 being ^
13683 per ha and the highest ^ 19346 per ha in 2006-07 with an average of ^ 16103 per ha.
These results supports that land is being ledaimed and as such farmeTS are willing to spent
more on inputs for crop production. Similar information emerged for the paddy crop.
WaSim model calibrated and validated earlier for the inland basin of Haryana was
used to assess the sah status of the soil/water and water table behaviour on the drained lands.
Soil salinity reduced rapidly from 6.3 to 1.49 dS/m at the end of the monsoon season in the
first year itself in response to the installation of the drainage system. It appeared that at least
2 monsoon seasons rainfall is required before EC reached level for no effective build-up of
salt in the root zone thereafter. Similarly drainage effluent salinity revealed that initially it
increased from 6,34 dS/m to 6.63 dS/m and thereafter reduced at a slow rate from 6.63 to
2.95 dS/m from June 2004 to December 2005. The results support the earlier findings that
water quality generally improves in 2-3 years of operation and thereafter attains a nearly
constant value.
The model was also used to assess various scenes with scenario-building capability of
the model to assess future trends with various management options. Two extreme conditions
i.e. dry and wet rainfall years, along with a normal rainfall year and a combination of wet,
normal and dry years used to predict the water table depth for the experimental site. A was
also tried. In none of the four scenarios water table ever reached within 30 cm depth from the
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