The Next Step for Berries: Precision Fertigation

Transcription

1 The Next Step for Berries: Precision Fertigation by: Marcus van Heyst (M.Hort.Sc.) National Sales Manager Powerplants Australia Pty Ltd

2 Introduction Hydroponics definition Fertigation system types Control requirements Sensors Recycling Water treatment

3 Plant requirements

4 Plant Nutrients Macro Nutrients Micro Nutrients Primary Fe Iron N Nitrogen B Boron P Phosphorus Cu Copper K Potassium Mn Manganese Secondary Zn Zinc Ca Calcium Mo Molybdenum Mg Magnesium Cl Chloride S Sulphur

5 Plant Nutrients

6 Plant Nutrient Availability with ph

7 Challenge Delivering the plant s nutritional requirements Accurately Uniformly Timely Automatically

8 Dosing System Types Stock tanks Simple injection Venturi injector Proportional injector Automated dosing Batch Tank System Inline Direct Injection System ByPass Direct Injection System Mixing Tank System

9 Stock Tanks 100 : 1 concentrate Less mixing needed A & B tanks, why? Calcium + Sulphate = Gypsum For every 1000 litres of irrigation, inject: 10 litres of A solution 10 litres of B solution

10 Simple Injection Venturi injector Proportional injector

11 Venturi Injection Venturi: The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe.

12 Venturi Injector

13 Venturi Injection Advantages: Simple No moving parts Inexpensive Disadvantages Pressure loss Not proportional

14 Proportional Fertiliser Injection Delivering soluble fertiliser in fixed proportion to water volume. e.g. 1 : 100

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16 Proportional Injectors Advantages: Maintain correct ratio water:fertiliser Relatively inexpensive Relatively simple to operate Disadvantages Pressure loss Limited capacity Wear causes loss of accuracy

17 Automated Dosing Batch Tank System Direct Injection Inline ByPass Mixing Tank Dosing

18 CONTROLLER Batch Tank System ph ACID/ ALKALI TANK IRRIGATION VALVES A B FERTILISER STOCK TANKS ph EC SENSORS CIRC. PUMP RECIPE TANK IRRIGATION PUMP

19 Batch Tank System Advantages: Relatively low cost Very accurate Disadvantages One recipe One EC Slow to change

20 Inline Direct Injection System FRESH WATER TANK MIXING CHAMBER PUMP ACID/ALKALI TANK ph SENSORS EC ph FERTILISER STOCK TANKS A 1 B 1 A 2 B 2 CONTROLLER

21 Mixing Chamber Design A2 A1

22 ByPass Direct Injection System CONTROLLER FRESH WATER TANK IRRIGATION PUMP BYPASS PUMP OUT ph EC SENSORS MIXING CHAMBER ACID TANK ph A 1 B 1 RECIPE 1 FERTILIZER STOCK TANKS A 2 B 2 RECIPE 2

23 Direct Injection Advantages: One pump Multiple recipes Fast recipe change Disadvantages Less accurate ph correction difficult

24 Direct Injection

25 Mixing Tank System FRESH WATER TANK MIXING TANK MAIN PUMP CONTROLLER OUT FILL PUMP EC ph SENSORS ACID TANK ph A 1 B 1 RECIPE 1 FERTILIZER STOCK TANKS A 2 B 2 RECIPE 2

26 Mixing Tank Dosing Advantages: Accurate EC and ph control Multiple recipes Disadvantages Two pumps More expensive

27 Mixing Tank Systems

28 Control what to look for Dosing control Recipes: Stock tank selection EC measurement and injection 2 sensors ph measurement and injection sensors Flow measurement and control Filter back-wash control Irrigation cycle control Sensor technology Recycling

29 EC / ph Control Light influence on EC Different recipes for different crops/varieties/growth stage Each recipe with EC and ph setpoints ph control to lower, or raise ph

30 Irrigation Cycle Control Multiple Periods Valve Groups, based on crop type Variety stage of growth Valve Irrigation Frequency & Duration influenced by light

31 Sensor technology Light measurement: Linear Light: klux/klux per hour Solerimeter: W/m 2 and joules PAR: nm, µmol/sm 2 Drain EC & Volume Measurement Substrate Moisture/EC/Temp measurement Groscale

32 Measuring Light

33 Drain measurement Measurement of drain EC and volume in real time. Indication of substrate EC and ph Calculation of drain %-age

34 Substrate Moisture/EC/Temp

35 Fruit Optimizer Uses change in plant weight to determine when the crop needs irrigation Irrigation based direct crop measurement Scheduling no longer fixed

36 Fruit Optimizer

37 Recycling Why recycle? Save water (up to 50%) Cost of treating water Save fertiliser (up to 60%) Save the environment

38 How do I recycle? FRESH WATER L B EC TREATMENT/ DISINFECTION TREATED WATER L TO CROP GUTTERS B B DRAIN WATER SUMP L

39 Water disinfection Why? Reduce the risk of spread of water borne pest & disease Options: Chemical water disinfectant dosing e.g. Twin Oxide UV water disinfection

40 Chemical water disinfectant Proportional injection of a chemical effective against a wide range of diseases, without any phytotoxic effects. Select appropriate product. Determine appropriate application rate Select appropriate delivery system Ensure safe handling

41 Chemical water disinfectant Benefits: Low installation cost Residual effect irrigation components, media

42 UV Disinfection Treating water by exposure to high level of UV-C ( nm) radiation. Radiation level expressed in mj/cm 2 Proven technology - Independent tests in the Netherlands Different rates for different levels of treatment Low running cost Very little effect on nutrients in the water Self monitoring

43 UV Disinfection - rates 60 mj/cm 2 Pythium & Phytophthera, bacteria and nematodes 80 mj/cm 2 Fusarium, bacteria and nematodes 150 mj/cm 2 Some viruses, fungi, bacteria and nematodes 250 mj/cm 2 Total disinfection of all viruses, fungi, bacteria and nematodes

44 UV Disinfection Higher initial investement Water must be tested for UV T-10 Pre-filtration requirement Some effect on chelates

45 UV Disinfection

46 Questions? Powerplants Australia Pty Ltd 27 Technology Circuit Hallam VIC 3803 PH FX