A LOW COST DRIP IRRIGATION SYSTEM FOR ADOPTION IN JHUM AREAS IN NAGALAND FOR FOOD SECURITY. National Workshop on‐ Challenges in Irrigation Management for Food Security

1. A LOW COST DRIP IRRIGATION SYSTEM FOR ADOPTION IN
JHUM AREAS IN NAGALAND FOR FOOD SECURITY
National Workshop on‐
Challenges in
Irrigation Management for Food Security
Prof.(Dr.) Arnab Sarma
Head, Department of Civil Engineering, p g g
Royal School of Engineering & Technology
Betkuchi, Guwahati‐781035
Nov‐2016

2. MAP OF NAGALAND

3. JHUM IN NAGALAND
• Also called the Slash‐and‐burn or shiftingAlso called the Slash and burn or shifting
cultivation has historically been in existence in
tropical areas (high rainfall) for the last 7000‐tropical areas (high rainfall) for the last 7000
10,000 years as a form of RAINFED FARMING.
• In Nagaland, jhum constitutes as much as 76% of
h d (UNDP)the cropped area (UNDP).
• At least 100 different indigenous tribes of NER
depend on jhum for their subsistence.p j

4. TWO SCHOOLS OF THOUGHT EXIST
School 1: ve ecological impacts primitive inefficientSchool‐1: ‐ve ecological impacts, primitive, inefficient
School‐2: It is an integrated 0‐Tillage System thatSchool 2: It is an integrated 0 Tillage System that
meets all the food requirements of Hill People
Jhum is considered by many to be a “remarkableJhum is considered by many to be a remarkable
form of organic farming” that WAS self‐sustaining.
School‐1 appears to prevail
The practice is under the pressure of modern systemsThe practice is under the pressure of modern systems
of land tenure, which discourage it.
But it continues unabated in the NER albeit withBut it continues unabated in the NER, albeit with
certain modifications

5. CROPS ON A JHUM FIELD

6. Jhum Pockets on the Hills of Mokukchung Town

7. Self‐Regenerated Area (Post Jhum)

8. Crops Grown in Jhum Land

9. CROP YIELD IN JHUM AREA
• Rice : 0 7 1 4 MT/ha• Rice : 0.7 ‐ 1.4 MT/ha
• Other crops : Up to 1 MT/ha (no precise data)
• Note: As many as 15‐20 crops are harvested from
an area of 1‐4 ha (standard Jhum Pocket)
Low Productivity & Food Insecurity‐ Causes
• Local Seeds
• No Crop Rotation (few plant nitrogen fixing crops)
• Non‐availability of timely irrigation
• Reduced FERTILITY of soil due to INTENSIFICATION• Reduced FERTILITY of soil due to INTENSIFICATION
OF JHUM CYCLE (Population Increase).

10. YIELD OF CROPS IN JHUM LAND

11. IMPACT OF UNDP PROJECT
• Initiated in 2009 (Mon Mokokchung & Wokha districts)Initiated in 2009 (Mon, Mokokchung & Wokha districts)
• The project integrated‐
C Li k Fi h i–Crop Livestock Fisheries
–forestry and Horticulture
–Measures to reduce soil erosion
Impact assessment done in 2014‐15 (by InsPIRE)
Impact:Impact:
–improved vegetation cover by 2,100 ha of land
i j tin project areas.

12. Looks Like an Improvement (after UNDP)

13. Looks Like an Improvement (after UNDP)

14. CURRENT TYPES AND TREND IN JHUM
TYPESTYPES:
 Jhum only
 Cash crop + jhum crops
 Mixed farming (jhum+ limited agriculture in plain Mixed farming (jhum limited agriculture in plain
land). This includes cultivation of fruit, timber etc
 Sequential conversion of jhum to horticultural Sequential conversion of jhum to horticultural
cropping & Integrated Farming (This is the Trend)
 Th l t t h th hi h t t ti l i t The last system has the highest potential in terms
of economic sustainability.
(Here, Micro‐Irrigation Can do the Miracle)

15. The hypothesis & Remedy
• Population Increase leading to intensification• Population Increase leading to intensification
(reduction) in Jhum cycle (10‐12 Years to 3‐4 Years)
• The reduced Cycle leads to rapid loss of forest
resources.
Probable Remedies:
• Settle the Jhumias (i.e. stop LAND ROTATION)
I t d CROP ROTATION & NOT LAND ROTATION• Introduce CROP ROTATION & NOT LAND ROTATION
• Productivity increase through Micro Irrigation
(water being scarce) besides other agri‐inputs

16. Drip Irrigation in Nagaland‐ Present status
Year 2001‐02 2002‐03 2003‐04 2004‐05
Area (ha) 60 55 100 50
Abysmally Low‐ Despite Potential
Moreover, Hill agriculture is almost 100% Organic.
/Else nobody will eat/demand.

17. BAMBOO DRIP SYSTEM OF THE “NER”
• Usually about 4 5• Usually about 4‐5
diversion stages before
water is delivered atwater is delivered at
the base of the plant.
• About 18‐20 lpm of
water from the main
channel gets reduced
to about 10‐80 drops/
minute at end of the
network

18. WATER DISTRIBUTION‐ BAMBOO DRIP

19. Description of the proposed System (1)
(i) W di i Thi i h b l h i ll A l(i) Water diversion system: This is shown below schematically. Actual
design dimensions will have to be worked depending on location and
field conditions.
(ii) Water tank: Of suitable dimension depending on field requirement
and condition (placed 1 m & above ground level) for smaller systems up (p g ) y p
to 400 m2 area.
(iii) Control valve: To regulate pressure & flow of water into the system.( ) g p y
(iv) Filter: For clean water to enter into the system
(v) Mainline: 50 mm PVC (Poly vinyl chloride) or PE (Polyethylene) pipe
to convey water
(vi) Sub‐main: PVC/PE pipe (not shown in Figure) to supply water to the
laterals that are connected to the sub‐main at regular intervals.

20. Description of the proposed System (2)
(vii) Lateral: PE pipes along the rows of the crops on(vii) Lateral: PE pipes along the rows of the crops on
which emitters are connected directly. The size
(diameter) of pipe may be 12 16 mm(diameter) of pipe may be 12–16 mm.
(vii) Emitters/micro‐tubes: Device through which ( ) / g
water is emitted at the root zone of the plant with
required discharge. q g

21. Schematic layout of the proposed system

22. HEADING‐UP WATER AND DIVERSION

23. COMBINED BOULDER AND WOOD CHECK FOR
HAEDING‐UP STREAM WATER FOR DIVERSION
(Local Materials to be Used)

24. Tackling Irrigation Uniformity
• Achieving a high uniformity is challenging in hillsAchieving a high uniformity is challenging in hills.
• An elevation change of 2.3 feet may cause a 1 psi
change in pressure in a drip linechange in pressure in a drip line.
• Drip tape on a 5% sloped field, would have a change
i f b 6 i l 300’ diin pressure of about 6 psi along a 300’ distance.
• More water would be applied at the lower end of
the field compared to the top of the slope {Q=f(h)}.
• The result would be that the extra water applied at pp
the lower end of the field may saturate the soil fully
• This is likely to promote soil borne root diseasesThis is likely to promote soil borne root diseases

25. Managing elevation change
• In a slopped land such as jhum land the water• In a slopped land such as jhum land, the water
pressure of the mainline will vary among irrigation
blocks located at different elevations relative to theblocks located at different elevations relative to the
water source.
If th bl k i b l th t ( b i i• If the block is below the water source (obvious in
slopped land), then pressure in the mainline may be
hi hhigh.
• In this case the blocks are to be adjusted to the
same pressure in order to apply water uniformly
and solutions to this effect are available.

26. • Orienting beds with the contours of the slope can• Orienting beds with the contours of the slope can
minimize elevation changes along the bed.
• Elevation changes should be less than 2%, which
equates to a pressure difference of about 2 6 psiequates to a pressure difference of about 2.6 psi
between the beginning and end of the bed of 300'.
• Shortening the length of the beds can also
minimize the elevation change along the beds, but
may be costly as extra hardware would be needed.

27. • Increasing the operating pressure can minimize the
l ti ff t if it b thelevation effects on uniformity because the
variation in pressure becomes less relative to the
average pressure.
• However, this may require use of THICK WALLED
TAPE/PIPE to prevent bursting of the tape/pipe
thereby adding to system costs.

28. Reducing drainage water on slopes (1)
• When drip systems are placed on sloped ground• When drip systems are placed on sloped ground
the common problem (after the irrigation ends) is
that the remaining water in the sub main lateralthat the remaining water in the sub‐main, lateral
and drip lines drains to the low end of the field,
saturating the soilsaturating the soil.
• If the slope of the field is oriented along the beds,
then adding flush valves to the end of the drip
lines can release trapped water.

29. Reducing drainage water on slopes (2)
A l l l l b d t• A low pressure release valve can also be used to
release water trapped in the lower end of the
b i /l t lsubmain/lateral.
• The outlet of the low pressure release valve can be
fitted with a hose so that water can be drained
away from the field into a retention basin, if
possible. This is possible in Jhum areas with
drainage lines.

30. Prescribed care for water source
Th itt i d i t h ll di tThe emitters in a drip system have small diameters
that can easily become clogged.
Organic materials (plant materials, algae, inorganic
sand, silt, and clay etc) are of concern
Surface water might have contaminants from runoff
In the proposed system therefore, a stilling cumIn the proposed system therefore, a stilling cum
cleaning basin kind of an arrangement is made use
of just after diversion of the water from stream.o just a te d e s o o t e ate o st ea .
In case of water sourced from the water harvesting
structure a low cost locally developed filtration is tostructure, a low cost locally developed filtration is to
be used. (Options being explored)

31. COST BENEFIT ANALYSIS
• The cost‐benefit analysis for the system is yet to be
done as the price of the component parts of thedone as the price of the component parts of the
system in the various markets of Nagaland are not
fully knownfully known.
• Thus, it would be early and immature at this stage
to firm up any opinion on that.
• Moreover, the field trial of the system is pending.Moreover, the field trial of the system is pending.

32. Problem Expected
• Even if the system is found to be economically• Even if the system is found to be economically
viable & technically feasible, the main problem
anticipated at this stage is ADOPTION by the localanticipated at this stage is ADOPTION by the local
farmers in general and the shifting cultivators in
specific.p
• ACCESSIBILITY to high land areas are extremely
difficultdifficult
• However, with the extension machinery of theHowever, with the extension machinery of the
Govt. of Nagaland and the NGO (Tribal Farmers’
Association, Peren) these hurdles could be, )
overcome.

33. Some Components

34. TRAINING THE FARMERS
Farmers are taught to make pin holes in the plasticFarmers are taught to make pin holes in the plastic
tube and micro‐tubes inserted for water to pass.
Space between emitters is variable (between
plants, within and between rows). Usually one
emitter for each plant is to be provided.
Depending on the flow rate of water different sizesDepending on the flow rate of water different sizes
of valves, mainlines etc can be used.
Additional components include joints/connectors
and pegs (used to hold the lateral & micro‐pipes in
place). Bamboo to be used for all these.

35. CONCLUSION
Th id f thi t ti i t ti l t• The idea of this presentation is not entirely to
suggest the best Drip System for hill area.
• Jhum cannot be eradicated without a substitute.
We may make it productive by settling the Jhumias
• Since a Trend has already been set for gradual
modification of hill farming as mentioned above,
the irrigation engineers need to play their part of
providing water in a sustainable manner to
increase crop yield in such areas.
• We must not forget that Jhumias are part of ourg p
Inclusive Growth Agenda

36. CONCLUSION
• Water Resources Departments/Agencies and• Water Resources Departments/Agencies and
IITs should adopt such areas and start
OUTREACH PROGRAMMES for benefit of HillOUTREACH PROGRAMMES for benefit of Hill
Farmers
• By doing so we stand to become the biggest
beneficiaries. Because, planned agriculture
th hill l fl di d lon the hills mean less flooding and lesser
siltation of our reservoirs and productive
agricultural land in the plain areas ensuringagricultural land in the plain areas ensuring
food security for all.
This is a WIN‐WIN situation for both.

37. CONCLUSION (Dam Builders‐Be Careful)