Irrigation and Fertigation Control

Transcription

1 Irrigation and Fertigation Control Marc van Iersel Irrigation: Why worry? Overlooked, but critical task Has major impact on quality Affects fertilization 1

2 What determines water use? Plant size Environmental conditions Two components to water use 2

3 High water use Low water use Transpiration and stomates VPD Stomatal opening depends on light 3

4 Vapor pressure deficit Vapor pressure (kilopascals) 7 Saturation vapor pressure Temperature ( o Fahrenheit) Vapor pressure deficit Vapor pressure (kilopascals) Saturation vapor pressure Actual vapor pressure (40% RH) VPD Temperature ( o Fahrenheit) 4

5 Vapor pressure deficit Vapor pressure (kilopascals) Saturation vapor pressure Actual vapor pressure (40% RH) Vapor pressure deficit (40% RH) VPD Temperature ( o Fahrenheit) Irrigation practices Based on grower judgment Likely results in overwatering Timers Don t adjust for crop size or weather Light or VPD accumulator Doesn t adjust for crop size 5

6 SCRI-MINDS Managing Irrigation and Nutrition via Distributed Sensing This project is all about water Providing real time information to growers About their microclimatic conditions To schedule irrigation applications Based on specific crop requirements What we have done: Developed Wireless Sensor Networks, with monitoring and control capabilities (hardware) Developed a Graphic User Interface, for intuitive decision making (software) Developed guidelines to Manage Irrigation Quantified impact on production (Quality, fertilization, runoff) Determined the Economic Impact of better irrigation management ($$$) 6

7 What is a Wireless Sensor Network? Production areas Sensors Irrigation Controller Valves Radio Communication Graphic user interface Local Computer Grower Input Remote Computer or Smartphone What is a Wireless Sensor Network? Hardware Sensors Nodes Valves nr5 Software Data visualization Decision making 7

8 Automated Irrigation System GOOD DRY!! Solenoid Valve H 2 O Observed benefits Water savings Plant quality Faster growth Fertilizer savings Environmental 8

9 Precision Control of Irrigation Water use reductions between 40 and 85% Precision Control of Irrigation A 50% reduction in irrigation saved over 43 million gallons of water in one nursery in 2012 Saved $6,500 in pumping costs In California (water costs are ~$750 / acre foot), this water costs ~$100,000 9

10 Impact on Water Availability Cost of water is low compared to other variable costs Some operations are limited by the well or pump capacity Tree nursery was able to install an additional 30-acre production Cut Snapdragons (Flowers by Bauers) 10

11 Economic Analysis: Total Stems Pre-Sensor: ( ) Post-Sensor: ( ) % % 31% 32% 5% GROUP 1/2 GROUP 2 GROUP 2/3 GROUP 3 GROUP 3/4 Lichtenberg et al, 2015 Economic Analysis: $ /stem Pre-Sensor: ( ) Post-Sensor: ( ) $0.70 $0.60 $0.50 $0.40 $0.30 $0.20 $0.10 $0.00 GROUP 1/2 GROUP 2 GROUP 2/3 GROUP 3 GROUP 3/4 Lichtenberg et al,

12 Economic Analysis: Annual Profitability Pre-Sensor: ( ) Post-Sensor: ( ) Difference Change Crops/ year % Stems/ year 106, ,382 33, % Price/ stem $ 0.59 $ 0.62 $ % Labor costs $ 15,905 $ 17,893 $ 1, % Electricity $ 4,109 $2,923 $ 1, % Sensor system $ 0 $7,147 $ 7, Revenue $63,094 $ 85,679 22, % Profit $43,080 $57,716 $14, % Payback period on upfront costs <16 months Lichtenberg et al, 2015 Cut Snapdragons (Flowers by Bauers) Increased yields Improved quality = more profit 12

13 Alternative to Plant Growth Regulators Reduced substrate water content reduces elongation Tracking curves to monitor poinsettia height Height from the Bench Top (inches) Cultivar: Classic Red 7 25 Aug 1 Sep 8 Sep 15 Sep 22 Sep 29 Sep 6 Oct 13 Oct 20 Oct 27 Oct 3 Nov 10 Nov 17 Nov 24 Nov Date 13

14 Growth tracking curves 20 14" 15.5" Lower limit Upper limits Height Height (inches) " Control Height (inches) Days after pinching " 15.5" Substrate volumetric water content (%) " Control Days after pinching 14

15 Final plant height 35.6 cm 39.4 cm 43.2 cm control Bract size 35.6 cm 39.4 cm 43.2 cm control 15

16 Better Growth Feb 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 Sept 2011 Oct 2011 Nov 2011 Dec 2011 Jan 2012 Feb 2012 March 2012 April 2012 Number of plants Faster production cycle Forecast sales 0 Month 16

17 Number of plants Faster production cycle Forecast sales Actual sales 23,400 plants New Crop Feb 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 Sept 2011 Oct 2011 Nov 2011 Dec 2011 Jan 2012 Feb 2012 March 2012 April 2012 Month Is it real? Ready Oct month production cycle 17

18 Disease Management Sensor-based irrigation decreased disease-related shrinkage in Gardenia from 30% to virtually zero Profitability of Wireless Sensor Networks Analysis by Erik Lichtenberg, Univ. of Maryland Potential benefits found include: Water/energy/labor savings Reduced losses Reduced management time Accelerated production time 18

19 System payback: less than one month! No Sensors Sensor- Based Irrigation Annualized Revenue $66,297 $ 145,505 Annualized Production Expenditures $30,539 $50,039 Annualized Sensor System Cost (3-year Lifetime, 6% Interest) $ 0.00 $3,755 Annualized Profit $35,758 $91,710 Annualized Profit per Acre $78,000 $ 200,000 Percent Change from Base Case +156% Water & fertilizer interactions Fertigation; water soluble fertilizer excessive irrigation result in high fertilizer application Excessive watering leaches nutrients from containers Nutrients movement in the substrate: mass flow diffusion dependent on water in the substrate Thus plant nutrient uptake depends on substrate water content 19

20 1/18/2017 Water & fertilizer interactions Bigger plants less flowers Best plants Water & fertilizer interactions Can fertilizer concentrations be decreased with more efficient irrigation? Because of less leaching Or do fertilizer concentrations need to be increased? Because less water is applied 20

21 Materials and methods Petunia Apple blossom was grown in 6 pots Treatments Fertigation at two fertilizer concentrations 100 and 200 ppm N ( Cal-Mag) Soil moisture sensor-based drip irrigation system used Solenoid valve 21

22 Treatments Four irrigation treatments (volumes): Control, Low, Medium & High leaching Data collection Leachate collected weekly 22

23 Leaching volume Total leaching volume (ml/plant) Fertilizer N concentration 100 mg L mg L -1 b ab a a Control Low Medium High Irrigation volume Shoot dry mass 100 mg L Shoot dry mass (g/plant) a a a a 0 Control Low Medium High Irrigation volume 23

24 Shoot dry mass mg L mg L -1 b b b b Shoot dry mass (g/plant) a a a a 0 Control Low Medium High Irrigation volume CONCLUSIONS Irrigation and leaching volumes did not affect plant growth No evidence fertilizer concentrations can be reduced with more efficient irrigation 24

25 Reduced fertilization Water-soluble fertilizers: Less water = less fertilizer CRFs: Less water = less leaching Less runoff Financial savings $5 10 million/year in Georgia alone Towards commercialization Decagon s PlantPoint system, being released now 25

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27 HortTechnology Special Series: Improving Irrigation with Sensor Networks: Implementation and Impact content/23/6.toc 27

28 Low-cost alternative: Arduino Build your own irrigation controller Open source microcontroller (Arduino) 28

29 Environmental Benefits 50% industry adoption rate in the ornamental industry: Save enough water for 400,000 households a year Prevent 620,000 lbs. of nitrogen and 400,000 lbs. of phosphorus from entering the environment 29

30 Benefits Control over plant quality Reduced disease pressure Less leaching and runoff Water and fertilizer savings Higher profits Funding provided by USDA NIFA SCRI Award no SCRI-MINDS Managing Irrigation and Nutrition via Distributed Sensing 30