Agricultural irrigation systems include center pivot, drip, sprinkler, and surface irrigation. Pumps deliver water from wells, rivers, or reservoirs to fields at required pressure and flow. This guide covers pump selection for agricultural irrigation systems.
Irrigation Systems and Pump Services
| System | Water Source | Typical Flow | Typical Head | Key Characteristic | Pump Type |
|---|---|---|---|---|---|
| Center pivot | Well, river, canal | 50โ200 mยณ/h per pivot | 20โ50 m (system pressure 1.5โ4 bar) | Continuous, variable flow (pivot speed), clean/sandy water, remote operation | Vertical turbine (well) or horizontal split case (surface water) |
| Drip irrigation | Well, reservoir, treated effluent | 10โ100 mยณ/h per block | 10โ30 m (1โ3 bar at emitter) | Low flow, precise pressure, filtration critical (emitter clogging), fertigation | 316L/bronze centrifugal (clean, low head) + booster + filtration |
| Sprinkler (solid set/hand move) | Well, river, canal | 30โ150 mยณ/h | 30โ60 m (3โ6 bar at sprinkler) | Moderate flow, moderate head, intermittent (set moves), sandy water | Horizontal split case or vertical turbine |
| Surface/furrow | River, canal, reservoir | 100โ1000 mยณ/h | 5โ15 m (low head, gravity) | Very large flow, very low head, dirty water, intermittent | Axial flow or mixed flow (very large flow, low head) |
| Well water (submersible) | Deep well (10โ300 m) | 10โ200 mยณ/h | 50โ300 m (well depth + system) | Deep water, clean, continuous, high head, submersible motor | Vertical turbine (lineshaft) or submersible turbine |
| Booster (pressure) | Main line | Variable | 10โ30 m additional | Variable flow, constant pressure, VFD, multiple zones | Vertical inline multistage (compact, VFD, constant pressure) |
| Fertigation/chemigation | Fertilizer/chemical solution | 0.1โ5 mยณ/h | System pressure | Corrosive (fertilizer, acid), precise dosing, injection into irrigation line | Diaphragm metering (precise, chemical-resistant, PTFE) or venturi injector |
| Filtration backwash | Clean water (reverse) | 50โ200 mยณ/h | 10โ20 m | High flow, intermittent, clean, air scour (if combined) | 316L centrifugal (high flow, intermittent) |
| Drainage (field/subsurface) | Field drainage water | 20โ200 mยณ/h | 5โ20 m | Dirty water (sediment, organic), intermittent, low head, corrosive (fertilizer runoff) | Submersible or slurry (dirty, solids) |
| Effluent/reclaimed water | Treated wastewater | 50โ500 mยณ/h | 20โ50 m | Corrosive (nutrients, residual chlorine), biological, solids, filtration critical | 316L/duplex or submersible (corrosion-resistant, solids handling) |
Critical: Well Water (Deep + High Head + Clean)
Well water is the most common irrigation source โ pump selection depends on well depth:
- Deep well (๏ผ50 m): Use vertical turbine pump (lineshaft, motor at surface) or submersible turbine (motor underwater). Multistage (each stage adds ~10โ30 m head). Bronze/316SS wetted (clean well water). Nylon/rubber bearings (water-lubricated). Continuous duty. High efficiency.
- Shallow well (๏ผ10 m): Use self-priming centrifugal or jet pump. Above-ground installation. Easy maintenance. Lower head (10โ50 m).
- Well yield: Pump flow must match well yield (don't pump faster than well recharges). Drawdown test. Variable speed (VFD) to match yield. Minimum flow (cool motor). Cycle control (pressure tank).
- Sand/sediment: Some wells produce sand โ wears pump. Use sand separator (centrifugal) upstream. Wear-resistant impeller (bronze, Ni-hard). Larger passage. Monitor sand content. Our vertical turbine range handles well water.
Critical: Drip Irrigation (Low Flow + Precise Pressure + Filtration)
Drip irrigation requires precise pressure and clean water:
- Low flow, precise pressure: Emitters require 1โ3 bar (10โ30 m head). Use centrifugal pump with VFD + pressure transmitter. Constant pressure control. Multiple zones (valve control). Booster pump if main pressure insufficient.
- Filtration critical: Emitters clog easily (0.1โ1 mm openings). Use 100โ200 mesh screen filter or media filter. Automatic backwash. Backwash pump (high flow, intermittent). Sand separator for well water. Disk filters for fine filtration.
- Fertigation: Inject fertilizer/chemicals into irrigation line. Use diaphragm metering pump (precise, chemical-resistant) or proportional injector. PTFE wetted (acid fertilizer). Backflow prevention (chemical can't contaminate water source). Flush after use.
Critical: Surface/Furrow (Very Large Flow + Very Low Head)
- Very large flow, low head: 100โ1000 mยณ/h at 5โ15 m head. Use axial flow pump (propeller, very large flow, very low head) or mixed flow (moderate head). Large diameter (300โ1000 mm). Low speed (propeller). High efficiency at design point. Flooded suction (river/canal).
- Dirty water: River/canal water contains debris, fish, sediment. Use trash rack upstream. Large passage. Open impeller. Periodic cleaning. Slurry pump if high sediment.
Material Compatibility
| Material | Clean well water (ambient) | River/canal water (ambient, dirty) | Fertilizer solution (NPK, acid) | Effluent/reclaimed (ambient, corrosive) |
|---|---|---|---|---|
| Cast iron/bronze fitted | Good (standard, clean) | Fair (debris, corrosion) | NOT (fertilizer/acid) | NOT (corrosive) |
| 316L SS | Excellent | Good | Good (dilute fertilizer) | Good (effluent) |
| Duplex 2205 | Excellent | Excellent | Excellent (acid fertilizer) | Excellent (corrosive effluent) |
| Cast iron (enamel coated) | Good | Fair | NOT | Fair |
| NBR/EPDM seals | Good | Good | Fair (fertilizer) / NOT (concentrated acid) | Good |
| PTFE seals | Good | Good | Excellent (acid fertilizer) | Excellent |
Critical: Clean well water = cast iron/bronze or 316L. River/canal = bronze/316L + trash rack. Fertilizer = 316L/duplex + PTFE (metering pump). Effluent = 316L/duplex. Drip = filtration + VFD pressure control. Well = vertical turbine (deep) or self-priming (shallow).
Common Problems and Solutions
Problem 1: Well pump wears out (sand). Well produces sand โ impeller/casing wear in 1โ2 years. Solution: sand separator (centrifugal) upstream. Wear-resistant bronze/Ni-hard impeller. Larger passage. Monitor sand content. Reduce flow (less sand entrainment). Use vertical turbine with wear-resistant construction. Our turbine range handles sandy well water.
Problem 2: Drip emitters clog (filtration inadequate). Sediment/algae/bacteria clog emitters โ uneven irrigation. Solution: 100โ200 mesh screen or media filter. Automatic backwash. Backwash pump. Sand separator for well water. Chlorination (biological). Flush lines regularly. Our filtration-compatible pumps support drip systems.
Problem 3: Center pivot pressure varies (uneven water). Pump pressure fluctuates โ pivot end gets less water. Solution: VFD + pressure transmitter (constant pressure). Booster pump for long pivots. Pressure regulating valves at pivot. Multiple pumps for large fields. Our VFD-controlled pumps maintain constant pressure.
Problem 4: Fertigation pump corrodes (acid fertilizer). Concentrated acid fertilizer attacks 304SS/NBR. Solution: use PTFE diaphragm metering pump (chemical-resistant). 316L/duplex for dilute. Flush with water after use. Backflow prevention. Venturi injector (no moving parts) for simple systems. Our metering range handles fertigation chemicals.
Problem 5: Surface irrigation pump clogs (debris). River/canal debris (leaves, fish, trash) clogs impeller. Solution: trash rack upstream (50โ100 mm spacing). Large passage open impeller. Periodic cleaning. Axial flow pump (large passage). Our axial flow range handles dirty surface water.
Selection Summary
- Deep well: Vertical turbine (lineshaft or submersible, multistage, high head, clean water, sand separator)
- Shallow well: Self-priming centrifugal or jet pump (๏ผ10 m, low head, easy maintenance)
- Center pivot: Vertical turbine or split case (continuous, variable flow, VFD, pressure control)
- Drip irrigation: 316L/bronze centrifugal + VFD + filtration (low flow, precise pressure, 100โ200 mesh, fertigation)
- Sprinkler: Horizontal split case or vertical turbine (moderate flow/head, intermittent)
- Surface/furrow: Axial flow or mixed flow (very large flow, very low head, dirty water, trash rack)
- Booster: Vertical inline multistage (compact, VFD, constant pressure, multiple zones)
- Fertigation: Diaphragm metering (PTFE, precise, chemical-resistant, backflow prevention)
- Filtration backwash: 316L centrifugal (high flow, intermittent, clean)
- Drainage/effluent: Submersible or slurry (dirty, solids, corrosive)
- Critical: well = turbine (deep) + sand control, drip = filtration + VFD pressure + fertigation, surface = axial flow (large/low head) + trash rack, all = match pump flow to water source yield, VFD for energy savings, filtration for drip/effluent
- Our vertical turbine covers wells; split case covers pivot/sprinkler; axial flow covers surface; metering covers fertigation. For irrigation pump selection, talk to our agricultural engineers with your water source, irrigation type, field size, and crop.