Drip irrigation is the most water-efficient way to grow, and the most unforgiving of a badly matched pump. Emitters are engineered for a narrow pressure window; feed them too little and the far rows starve, feed them too much and fittings weep while emitters mist instead of drip.
Know your demand precisely
Drip demand is a multiplication, not a guess: emitter count times emitter flow. Two thousand emitters at 4 litres per hour want 8 m³/h. That is a real pump, and it is why greenhouse systems are zoned: water a third of the benches at a time and a modest pump serves a large structure.
Pressure is the tighter constraint
Most drip lines want 1 to 1.5 bar at the tape, after filters and valves that eat pressure along the way. Size the pump for pressure at the emitter, not pressure at the pump flange. A system that delivers 3 bar at the manifold and 0.6 bar at the last row is a system that only irrigates the near half of the greenhouse.
Filtration protects both sides
Emitters clog; that is known. Less obvious is that greenhouse recirculation water carrying fertiliser and fines also wears the pump. A filter rated for the emitters protects the crop, and a strainer ahead of the pump protects the machine. Budget both.
Drip rewards precision. Match zones to pump capacity, keep the pressure window honest end to end, and the system quietly does the most efficient irrigation there is.