Low Cost Drip Irrigation for Rural and Urban Horticulture
In dry regions, it is possible to get some assured nutrition / income from small plots, without being subjected to the stress of water-scarcity, if a low-cost drip irrigation system is self-made and implemented. This can make a difference in the health and well-being for even malnourished people / children.
- To identify and develop low cost drip irrigation technologies for small plots, in water constrained regions / locations (say, schools, kitchen / home-stead / roof top gardens), using locally available materials and resources,
- To assess the water saving against conventional irrigation (where available) when drip irrigation is made available,
- To estimate the benefit / cost ratio due to drip irrigation technologies.
Land – small plots of land
A tree / stand, which children can build with materials locally available.
- Bucket-kit: Bucket (20 ltrs.) with an outlet / one main pipe (PVC or bamboo) / essential laterals / micro tubes / cloth wrapped punctures / used refills / etc.
- Drum-kit: Drum (25-100 ltrs.) with an outlet / one main pipe (PVC or bamboo) /essential laterals / micro tubes / cloth wrapped punctures / used refills / etc.
- Plastic water bottles (punctured / inverted), pitchers (with wicks) above or placed below the soil / canisters / etc.
Materials can be bought (the KB Eazy Drip in Maharashtra) or fabricated by the children. Useful contacts (if needed)-IDE (India), New Delhi, Local Krishi Vigyan Kendras or Agricultural Universities / Institutions.
Context dependent choice of plot and crop, preferably leafy vegetables – short duration, Manuring / fertilization / pesticide / chemical treatments as needed (SAU / local Agricultural Officer) Two similar plots – in one use Conventional irrigation / no irrigation and in the other Irrigation with drip method-plastic pipes / pitcher / bottle / any locally available material.
Estimate the water requirement / day:
Q=E ‘ Kp ‘Kc ‘ A
Where, E = evaporation rate of region
Q = amount of water required per day / plant
Kp = pan co-efficient (0.8 for most of Indian conditions).
Kc = crop co-efficient (1 for most of the crops in vegetative stage)
A = Area of wetting = p (d/2)2, or to be measured using grid / otherwise.
(Evaporation rates for the region can be collected from the District Meteorological Observatory or the Agro-meteorology Unit in the local Agricultural University or KVK)
Beaker and stop watch – to measure the flux from each dripper.
Once the crop’s water requirement has been established using the above formula, the water flow from each drip point (or a sample of points) has to be measured. If the flow is 10 ml per minute, and if the requirement per plant per day is 300 ml, then the water flow must be assured for 30 minutes. So the water in the bucket / drum /pitcher can be calculated accordingly, depending on the no. of drip outlets and plants population. Children may experiment with alternative crop layouts / water use patterns-say irrigating once in two days instead of everyday. The idea is to use water, labour for irrigation, energy for water lifting, etc. in a most cost effective fashion. Monitor the growth of the plant-once a week-they can measure physiological parameters such as no. of leaves, leaf area, plant height, and total plant weight (at the end of the harvest season) – notice any qualitative difference in the gardens (leafy vegetables).
All observations as shown in methodology.
- Plot layout, measurement etc. already specified. The layout of the main pipe, can be along the length (row) of the plot, and the laterals can run between two rows of plants, with the drip / nozzle or micro tube / filler (as the case may be), with the nozzle placed near the root zone.
- Fertilizer application-preferably early in the morning, just before irrigation.
- Crop care-use organic pesticides, dissolved in water, as and when necessary-tobacco / neem decoration.
- Measure all labour and materials used in the plot-including household labour of women in the home in fetching water/weeding / harvesting / marketing.
- Estimate economic benefits and costs
- Sum of all benefits (food / home consumption + marketed surplus + root growth retained in the soil after harvest + …….) / Sum of all costs (labour + material + land + rent + …….)
- Check for non-economic benefits and cost:
- Greater control for women over the small plot, better income and decision-making power for children / women /class (if the plot is in the school), less of chemicals / fertilizers,etc. more choice of vegetables at home etc.
- Compare the costs of irrigation and crop production in the two plots- conventional and drip irrigated.
Interpretation and use of data
Water-as a scarce resource-compare water saving against conventional irrigation
Ability to find and use local materials for drip / pitcher irrigation.
Benefits of locally available and accessible irrigation system for small plots can be estimated and popularized.
Children and their mothers can develop a small scale water use system, as well as local vegetable / horticulture produce market / use.
Implementation / Follow-up
The project has scope for innovation in all stages-depending on all local conditions, crop choices, urban or rural settings, materials available /modified / purchased / designed.
Innovation with actors / networks-leading to policy makers / local MLA’s to recognize the potential of precision irrigation and its practice in poor rural / urban households / schools / others.
Source: Harness water resources for a better future - Activity Guide for the 13th National Children's Science Congress