🌸 Drip and Fertigation Systems

This lesson builds core elective concepts in BSc Agriculture with practical applications and exam-oriented clarity.

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Drip and Fertigation Systems

Drip Irrigation

Drip irrigation (trickle irrigation) delivers water directly to the root zone of plants through a network of pipes, valves, emitters, and drippers at low pressure (0.5–2.0 kg/cm²).

Components

1. Head unit: Pump, filter (sand/disc/screen), pressure regulator, fertilizer injector
2. Main line: PVC pipe (63–110 mm) from head unit to sub-mains
3. Sub-main: PVC pipe (50–75 mm) connecting laterals
4. Laterals: LLDPE tubes (12–16 mm) with inline or online drippers
5. Emitters/Drippers: Deliver 2–8 litres per hour per point

Types of Drip Systems

Type	Feature	Use
Surface drip	Laterals on soil surface	Orchards, vegetables
Subsurface drip (SDI)	Laterals buried 15–30 cm	Sugarcane, turf, permanent crops
Micro-sprinkler	Small sprinkler heads	Wide-spaced orchards, frost protection

Water Savings

• 40–60% less water compared to flood irrigation
• Wetting only 30–50% of soil volume (reduced evaporation)
• Irrigation efficiency: 85–95% (vs 30–40% for flood)

Fertigation

Fertigation is the application of fertilizers through the irrigation system, combining water and nutrient delivery.

Injection Methods

• Venturi injector: Simple, low-cost, uses differential pressure
• Fertilizer tank (bypass): Concentrated solution diluted over time
• Injection pump: Most precise, proportional dosing (piston or diaphragm)

Fertigation Advantages

• Nutrient use efficiency: 80–90% (vs 30–50% for soil application)
• Precise placement: Nutrients directly in root zone
• Frequent small doses: Matches crop uptake curve, reduces leaching
• Labor saving: Eliminates manual fertilizer application

Fertigation Schedule for Mango (drip-fertigated)

Growth Stage	N:P:K Ratio	Frequency
Vegetative flush	2:1:1	Weekly
Flowering	1:2:1	Bi-weekly
Fruit development	1:1:2	Weekly
Post-harvest	2:1:1	Monthly

Water-Soluble Fertilizers

• Urea, MAP, MKP, SOP, potassium nitrate, calcium nitrate
• Micronutrient chelates (Fe-EDDHA, Zn-EDTA, Mn-EDTA)
• Must be fully water-soluble to prevent emitter clogging

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Summary Cheat Sheet

Topic	Key takeaway
Main focus	Drip and Fertigation Systems.
Section context	Revise this lesson with the rest of Hi-Tech Horticulture for stronger conceptual continuity.