HOW MUCH WATER DO I NEED ?

THE WATER SUPPLY MUST BE ADEQUATE TO LAY DOWN THE AMOUNT OF WATER REQUIRED TO IRRIGATE THE CROP, AND THE WATER MUST BE SUPPLIED AT A PRESSURE SUITABLE FOR THE CROP AND SOIL TYPE. THIS CALCULATION IS BEST PERFORMED BY AN IRRIGATION SPECIALIST. WE SHALL ANSWER THE QUESTION FROM THE POINT OF VIEW OF THE MACHINE. NAMELY, HOW MUCH WATER CAN IT DELIVER ?

SOUTHERN CROSS MANUFACTURES TWO IRRIGATOR MODELS. EXPERIENCE HAS SHOWN THAT IRRIGATOR GUNS SHOULD NOT, WITHOUT CAUTION, BE OPPERATED AT WATER PRESSURES LESS THAN ABOUT FOUR BAR (SIXTY POUNDS PER SQUARE INCH). SET UP FOR OPTIMAL USE THE TABLE BELOW SHOWS WHAT THE MACHINES CAN DO. PLEASE CONTACT SOUTHERN CROSS IN THIS REGARD AS MANY CONFIGURATIONS ARE POSSIBLE.

 

MODEL OPTIMAL FLOW RATE (CUBIC METRES PER HOUR) AREA IRRIGATED IN ELEVEN HOUR RUN WATER LAID DOWN (MM)
PCC MODEL 30 18.3 43 X 200 METRES (0.86 HA) 23.4
PCD MODEL 50 51.0 65 X 200 METRES (1.3 HA) 43.1

CONVERSIONS.

ONE CUBIC METRE PER HOUR = 0.28 LITRES/SECOND

ONE CUBIC METRE PER HOUR = 3.68 IMP GALLONS/MINUTE

THE ABOVE TABLE ALLOWS A SIMPLIFIED MECHANISM FOR CALCULATING IRRIGATION CAPABILITIES.

IN A FIVE DAY CYCLE THE MODEL 50 IRRIGATOR WILL LAY DOWN 43.1 MM OF WATER ON AN AREA OF THIRTEEN HECTARES. OR, BASED ON A TEN DAY CYCLE IT WILL LAY DOWN 43.1 MM ON AN AREA OF TWENTY SIX HECTARES. OR, CALCULATED YET ANOTHER WAY, IT WILL LAY DOWN AN AVERAGE OF JUST OVER EIGHT MM OF WATER PER DAY ON AN AREA OF THIRTEEN HECTARES WITH A FIVE DAY CYCLE.

THE AMOUNT OF WATER WHICH CAN BE APPLIED THROUGH A TRAVELLING IRRIGATOR IS LIMITED BY THE SIZE OF SUPPLY HOSE FITTED TO THE MACHINE. THE MODEL 30 UNIT HAS A 50 MM HOSE WHILE THE MODEL 50 UNIT HAS A 63 MM HOSE. THE HOSES ARE 100 MTRES IN LENGTH IN BOTH CASES.

SOUTHERN CROSS IRRIGATORS CAN BE CONFIGURED WITH DIFFERENT SPRINKLER (GUN) AND SPRINKLER NOZZLE SIZES SO THAT SHOULD THE AVAILABLE WATER SUPPLY BE LESS THAN SET OUT ABOVE THE IRRIGATOR CAN STILL FUNCTION.

MODEL 50 IRRIGATOR FITTED WITH 271/31 NAAN GUN

NOZZLE DIA (MM) PRESSURE AT GUN (BAR) FRICTION LOSS IN HOSE (BAR) WATER AT GUN (CUBIC M/HR) LANE SPACING (M) AREA COVERED IN 200 M RUN (HA) DEPTH 5.5 HOUR RUN (MM) DEPTH 11 HOUR RUN (MM) DEPTH 23 HOUR RUN (MM)
23 X 6.2 4.0 1.28 42.8 62 1.24 19.0 38 79.4
  5.0 1.41 48.2 66 1.32 20.1 40.2 84
  6.0 1.66 52.5 71 1.42 20.3 40.7 85
                 
17.8 X 6.2 4.0 0.47 26.8 54 1.08 13.6 27.3 57.1
  5.0 0.58 30.2 59 1.18 14.1 28.2 58.9
  6.0 0.67 33.5 62 1.24 14.9 29.7 62.1
                 
14 X 6.2 4.0 0.21 17.8 47 0.90 10.4 20.8 43.6
  5.0 0.26 20.2 50 1.00 11.1 21.2 45.5
  6.0 0.27 21.5 54 1.08 10.9 21.8 45.8

 

MODEL 30 IRRIGATOR FITTED WITH 268/32 NAAN GUN.

NOZZLE DIA (MM) PRESSURE AT GUN (BAR) FRICTION LOSS IN HOSE (BAR) WATER AT GUN (CUBIC M/HR) LANE SPACING (M) AREA COVERED IN 200 M RUN (HA) DEPTH 11 HR RUN (MM) DEPTH 23 HR RUN (MM) DEPTH 47 HR RUN (MM)
16 X 8.5 4.0 1.11 25.7 48 0.96 29.5 61.6 126
  5.0 1.36 28.8 52 1.04 30.5 63.7 130
  6.0 1.56 31.6 55 1.10 31.6 66.1 135
                 
14.5 X 8.5 4.0 0.86 22.5 45 0.90 27.5 57.5 118
  5.0 1.02 25.1 48 0.96 28.8 60.1 123
  6.0 1.14 27.5 50 1.00 30.6 64.0 131

 

THE ABOVE TABLES ARE NOT EXHAUSTIVE. PLEASE CONTACT SOUTHERN CROSS FOR OTHER COMBINATIONS.

RED NOZZLE TEXT INDICATES STANDARD SUPPLIED WITH MACHINE.

RETURN TO IRRIGATOR HOME PAGE............................................