How To Install Drip Irrigation
When learning how to install drip irrigation systems, a beginner starts by knowing the components.
They are;
1. A water source; a water body (river lake, reservoir), borehole or water tank
2. Method of water evacuation; by gravity or machine pumping
3. Main water pipe
4. Sub-main water pipes
5. Drip lines; the pipes which deliver water to the crop directly
6. Fittings; accessories that join the pipes to the water source, to the filter, and to each other
7. Water filter; a sieving system that keeps away solid particles from the drip irrigation system
In this one acre drip irrigation system, the raised tanks are the water source to which the main line is attached. Notice the filter and gate valve
How To Install Drip Irrigation Systems
Steps:
- Connect the main pipe to the water source if by gravity flow. Or to the water pump if you’re pumping
- Lay the main pipe on the surface, or bury it in a trench to the farm. Surface pipes are HDPE pipes. Sub surface pipes are PVC pipes, and HDPE pipes too
- Connect the smaller sub-main pipes to the main pipe in the farm. Sub-main pipes are smaller to increase pressure flow in the system. Connect with tees, elbows, valve sockets, and/ or saddle clamps.
- Connect the drip lines to the sub-main lines. Drill 16mm holes on the sub-main line. Put a rubber on it, hen a starter connector. Attache a 16mm HDPE pipe to the starter connector. Then an off-take connector to the 16mm HDPE pipe’s other end. Connect the to the off-take connector
An onion drip irrigation system installation by Grekkon Limited in Endarasha area, Nyeri county
How Drip Irrigation Works
Drip pipes irrigate through emitters on their surface. Emitters’ flow rate is liters per hour. Emitter spacing along the drip pipe is 10cm, 15cm, 20cm or 30cm. This according to the farmer’s crop, be it in the open field or greenhouse.
The emitter spacing, flow rate, and the water pump or gravity output determine;
- the irrigation block design
- amount of time taken to irrigate a given area
- the length of the drip line in a row of crop
This is standard when learning how to install drip irrigation kits for small farms, or systems for large ones
Illustration
Calculate the amount of water for a 30m long drip line. With a flow rate of 1.5 liters per hour, and an emitter spacing of 15 cm
(30÷0.15) × 1.5 = 300 liters per hour
Assume the following
i. An acre of crop measuring 63.3M x 63.M
ii. There are 1M wide beds with working spaces of 0.3M between them
iii. Each bed is 20M long
iv. Each bed has 3 rows of drip lines
The number of beds are (63.3/1.3) 49. The total length of the drip lines is (49beds x 60M length x 3 drip lines per bed) 8,820M
The number of emitters are (8,820/ 0.15M) 58,800. In an hour, your water source will provide (58,800 emitters x 1.5L per hour flow rate) 88,200 liters of water
If you are pumping, then this will be the capacity of your water pump
How To Determine The number of Drip Rows Per Planting Bed
This varies by crop. Larger crops utilise less drip lines per unit area, while smaller crops utilise more drip tape within the same space
The average planting bed size is 1M wide
- 1 drip row per bed crops; water melon, butternut
- 2 drip rows per bed crops; cabbage, potato, tomato, pepper, chillies
- 3 drip rows per bed crops; onion, garlic, green beans, herbs, spices
