Water and nutrients. Together.
Fertigation delivers fertilizer through the irrigation system — precise dose, exact timing, straight to the root zone. Less labour, better crop, lower input cost.
Benefits
Why fertigate.
Enhanced Nutrient Efficiency
Targeted, precise nutrient application straight to the root zone — minimises leaching and runoff.
Increased Crop Yield & Quality
Consistent nutrient supply throughout the growing season prevents deficiency gaps that limit yield.
Water Conservation
Water and nutrients delivered together — less waste, better utilisation of both inputs.
Time & Labour Savings
Eliminates manual fertiliser application. Schedule and frequency become flexible and automated.
Precision & Uniformity
Even nutrient distribution across the field prevents over- or under-fertilisation in any zone.
How it Works
Nutrient delivery in three phases.
Phase 1 — Pre-flush (15–20 min)
Run clear water through the system first to wet the root zone and open the emitters uniformly. This ensures nutrients are drawn into an already-moist soil — not a dry one that may cause salt burn.
Phase 2 — Fertigation (20–45 min)
Introduce the nutrient solution via Venturi injector or bypass tank. Nutrients travel through the lateral lines and are delivered directly to the root zone via drippers or micro-sprinklers.
Phase 3 — Post-flush (15–20 min)
Run clear water again after the fertilizer tank is empty. This clears residual nutrient solution from the pipes and emitters — preventing salt crystallisation, clogging and corrosion.
Injection Methods
Three ways to inject nutrients.
The method determines accuracy, cost and complexity. Venturi is the most common in Indian agriculture — simple, affordable, and power-free.
Venturi Injector
Creates a pressure differential that draws liquid fertilizer solution into the main pipe — no electricity, no moving parts.
Advantages
- No power required
- Simple to install and maintain
- Works with any water-soluble fertilizer
Limitations
- —Causes ~20–30% pressure drop in the system
- —Flow rate is fixed at installation
Best for: Small to medium systems (up to 5 acres), wherever power is not available
Available in ¾", 1" and 2" inlet sizes — stocked across Saurabh Shaktiman dealers
Bypass Fertilizer Tank
A pressurised tank connected in a bypass loop — water flows through the tank, dissolving and carrying nutrients into the system.
Advantages
- Simple construction
- No moving parts or electricity
- Handles granular fertilizers (must dissolve in water)
Limitations
- —Concentration decreases as tank empties (batch system)
- —Must refill and recharge for each application
Best for: Medium systems where consistent concentration is less critical — row crops, pulses
30 L / 60 L / 90 L / 120 L pressure-rated tanks available in Signet range
Proportional Injection Pump
An electric or water-driven positive-displacement pump delivers a metered dose of liquid concentrate proportional to water flow.
Advantages
- Precise constant concentration throughout injection period
- Can automate fertigation schedules
- Works with concentrated nutrient solutions
Limitations
- —Requires power (electric version)
- —Higher upfront cost
- —More maintenance than passive systems
Best for: Large, high-value systems — orchards, greenhouses, polyhouses where uniformity is critical
Not manufactured by Signet — recommend procurement alongside the drip system design
Fertilizer Selection
Only water-soluble fertilizers can be fertigated.
Granular NPK compounds must fully dissolve before entering the system — undissolved particles clog emitters. Use these water-soluble grades for reliable fertigation.
| Fertilizer | Form | Notes |
|---|---|---|
| Urea (46-0-0) | Solid / Liquid | Fully water-soluble. Most common nitrogen source for fertigation. Compatible with most systems. |
| MAP (Mono Ammonium Phosphate) | Solid | 12-61-0. High phosphorus source for early growth stages. Dissolves well in warm water. |
| MKP (Mono Potassium Phosphate) | Solid | 0-52-34. Phosphorus + Potassium. Highly soluble, low chloride. Good for fruiting stage. |
| Potassium Nitrate (KNO₃) | Solid / Liquid | 13-0-46. Clean, highly soluble N+K source — ideal for drip fertigation in all crops. |
| Calcium Nitrate | Solid | 15.5-0-0 + 19% Ca. For calcium nutrition in fruiting crops. Must NOT be mixed with phosphate or sulphate. |
| Magnesium Sulphate | Solid | MgSO₄. Supplemental magnesium for deficiency correction. Fully soluble. Use in dilute solution. |
Never mix calcium nitrate with phosphate or sulphate fertilizers in the same tank — precipitation will block the system. Alternate their application on different days.
Fertigation Schedule
N-P-K balance changes with crop stage.
Nutrient demand is not constant through the crop season. Adjusting the N-P-K ratio by growth stage is the key to unlocking fertigation's yield advantage over broadcast application.
| Crop | Growth Stage | N | P | K | Notes |
|---|---|---|---|---|---|
| Tomato / Capsicum | Vegetative (0–30 days) | High | Medium | Low | Emphasise N for leaf and stem development |
| Tomato / Capsicum | Flowering (30–60 days) | Medium | High | Medium | Boost P for root and flower development |
| Tomato / Capsicum | Fruiting (60+ days) | Low | Low | High | High K for fruit size, colour and shelf life |
| Sugarcane | Germination (0–30 days) | Medium | High | Low | P for root establishment |
| Sugarcane | Grand growth (30–180 days) | High | Low | Medium | N-heavy phase for maximum cane elongation |
| Banana | Vegetative (0–90 days) | High | Medium | Medium | Balanced growth — weekly fertigation |
| Banana | Bunch development (90–180 days) | Medium | Low | High | High K for bunch weight and finger size |
| Grapes | Pre-flowering | High | High | Low | Set up vigour and bunch structure |
| Grapes | Berry development | Low | Low | High | K for sugar accumulation and colour |
Indicative guidance only. Exact rates depend on soil test results, water quality and target yield. Consult an agronomist for a field-specific fertigation schedule.
Signet Fertigation Equipment
Everything from injection to emitter.
Venturi Injector
IS 14483 Part-1Differential-pressure venturi for fertigation — no moving parts, no electricity. Pulls fertilizer solution directly into the irrigation line under operating pressure.
Sizes: ¾" · 1" · 2"
Fertilizer Tank
IS 14483 Part-1Pressure-rated fertilizer tanks for in-line nutrient and chemical injection. Sealed, corrosion-free, easy to recharge mid-cycle.
Sizes: 30 L · 60 L · 90 L · 120 L
Drip Laterals (Fertigation-ready)
IS 13488 / IS 13487Signet Saurabh Shaktiman drip lines with wide-flow-path emitters resist clogging from fertilizer residue when the system is flushed after each fertigation cycle.
Sizes: 12 mm · 16 mm
Control Valves (PP)
Internal / ISOPP zone valves for isolating fertigation bypass loops and controlling application zones independently.
Sizes: 1" – 4"
- ●Upfront investment in injectors, tanks and metering equipment
- ●Requires technical knowledge of fertiliser chemistry — wrong combinations cause pipe clogging or nutrient lockout
- ●Regular system maintenance to avoid injector clogging or tank fouling
- ●Risk of over-fertilisation without monitoring — soil and leaf tests are recommended
Ready to add fertigation to your drip system?
Signet's agronomists can design a fertigation schedule for your crop and recommend the right injection equipment for your system size.