Focus on Nut and Fruit

CropsWater Efficient

Production

Water and Energy Saving,Sustainable Ag

Crop Water Stress in Almonds

AgendaSap Flow Solutions for Plant Stress MonitoringNew Technology to Supply Answers to Growers with Critical IssuesWith the right data, you will know how or when to irrigate or improve methods.

Why is this Different?

What is Important?

How does it Work?

How do I Benefit from this?

What is Needed?

Dynamax Background – Intro• World wide producer -transpiration Sensors since

1989• Started new subsidiary in Fresno, CA WET Center for

Monitoring Services April 15 2014. Focus on Almonds #1 crop in California.

• Manufacturer of 5 sap flow monitoring systems since 1991 - Flow32, FLGS-TDP, Flow-4, Probe-12 and SapIP.

• Patented SHB sap flow (1993), Micro Sensors (1994), and EXO-Skin Sensors (2013), and Sap flow irrigation controls (2006)

• Introduced first Self Healing Mesh Network nodes to Agricultural and Viticulture Industry 2010.

• Founder – Invented Neutron Probe (1956), Leaf Porometer (1965), and ET algorithms (1965 - 2005) – C.H.M. van Bavel

What Is Sap Flow?

All water transpired moves via Sap Flow through the stem / trunk or branches where it may be measured by the sap flow sensor ...

Also called sap flow collarssince the sensor wraps around the branch.

Needles – sap flow sensor methods.Heated probes inserted into the trunk

• Sap Velocity – Thermal Dissipation Probe, (TDP)

• Sap Velocity – Heat Pulse Velocity, (HPV)• Heat Ratio Method (HRM )

• (3 needles, center is heated)• HFD –Heat Field Deformation, 10 temp

sensors

• All the above require calibration and subject to non-uniform sap wood profiles. May require several sensors per trunk.

(Qf)

Our new sap flow sensor heats the stem by a heater strip with constant power. Measure the heat loss to the ambient (Qr). The remaining heat is carried by the sap (Qf)*

(Qr)

HOW? Measure the temperature increase (+) and convert the heat to a flow rate, based on the cooling effect of water (Specific Heat = Cp).

Heater Strip

Temp Sensor (-)

Temp Sensor (+)

* Stem Heat Balancemethod(S.H.B.)

Low Flow Rate, Heat only conducted outward, and temp is higher, 4-8 deg.

High Flow Rate, Heat dissipated by sap flow, and temp is lower, .5 to 1 deg.

(SF)high(SF) low

HOW?

Advantages:• Stem Heat

Balance (SHB) method does not require calibration.

• Non Invasive.

Requirements - The SHB type sensor is wrapped around the

stem or trunk Heater in firm contact, but flexible and

expandable. Apply stretch wrap. Temp sensors - accurate and in good

contact. Almonds require stem prep and clean.

Based on the physical property and mass of water(g), heat(J) and temp(C). [Cp = 4.186 J/g/C.]

HOW?

Shielding and insulation to prevent heat from the sun and irregular temp swings.

Requirements

Solar Power required to maintain constant heat (about 10 W per sensor)

Maintenance to observe stem, adjust for growth, check condensate and keep stem healthy.

Measure stems, input heater and plant properties into the logger / web site computations.

Real-time computations and communication to grower, and technical support.

Internet Protocol

Requirements – Real Time Data Data Access by Growers, Remote field data. Examples of a Sap Flow Network

Vineyards in Napa – Sonoma Network – Fruition Sciences

200 sites

Agrisensors.com

SapIP Loggers

Sap Flow Applications – SHB Method

• Commercial Irrigation – New Sensors and Systems for

• Orchards – Nuts, Fruit Trees• Crops – Corn, cotton, soybean• Viticulture – Wine grapes (7

years operations)• High value – fruits and plants

History of Apps SHB Method• Commercial and Government

Research (over 25 years) proven technology• Water Relations Studies – Competition • Crop Water Use – Irrigation studies• Breeding and genetic engineering - drought

tolerance• Nutrient and Disease Analysis• 100 reference papers

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Installation and Results

Starting July 1 Nonpareil – zone 1 and zone 2 (Test)Previous work to

validate methods in May - June

Survey and Tree selectionConsultation with CIT staff, Nov 2013, and Feb 2014.Sited at irrigation zones 1 and 2 (Test)Selection of healthy trees is importantRepresentative of Field (not outliers)Measure branches and select dominantIndex branch dimension to canopy as installations vary. All branches measured.

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InstallationSapIp Logger sited in Zone 1With solar and cellular gateway

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Branches measured and prepared for sensors

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Step 1- 2. Remove rough spots. Clean the sanded branch and spray with a thin layer of canola oil. This allows the sensor to move with plant growth.

Fit sensor on target branch.Step 3. Place a small amount of silicone grease to the inside of the sensor

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Step 4 - Install the sensor around the branch. Make sure the heater strip is overlapping to ensure proper contact and heating.

Wrap and insulate the sensor Step 5. Wrap EXO Sensor with

elastic Velcro strap, overlapping 1/8th to 1/4th inch starting from the middle of the sensor to the top and bottom.

Step 7. Install 3 foam insulator bodies around the EXO Sensor and above and below sensor zone, then attach sensor cable to designated Sap-IP channel.

Step 8. Install Gore-Tex waterproof jacket over foam bodies.

Install Solar ShieldingStep 9-10. Install 2 layers of reflective shield around EXO Sensor and insulate the branch below with more reflective shield.

Data Checking steps –Run sensor with and without heat to test and characterize thermal gradients and check operations.

BASIC Data CollectionSap Flow dataCIMIS Data - ETo for

comparisonAccumulate daily total and

check with weekly irrigation schedule

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Agrisensors login to site data

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 Select the Reports Tab and select the SapIPSITE 1 7/4 TO 7/9 1-6 days shows the quarter hourly sap flow readings. (g/hr). CIMIS data from Fresno State reported below.

7/4 To 7/9 ETo (mm)

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Time

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ETo (mm)

Chart Accumulated Water

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Accumulated Sap Flow Liters / Tree 1.

(~ 1 gal / day)

(3.8 liters)

Irrigation 18 hrs @July 3(250 gal), 12 h @ July 7.

Compare with Tree 2 - Stressed

-----Sap Flow Liters / branch (~ .5 gal / day)

We see that a crowded tree with competition for irrigation loses sap flow compared to an adjacent healthy tree.  The sap flow is ½ as much on the stressed tree, and it does not recover when it is watered.Water Management should not be based on the stressed tree, it would lead to under-watering the whole crop if used for a water replenishing budget. If used to gauge stress, and add more water to remove stress, it would lead to over-watering.

Irrigation 18 hrs @July 3(250 gal), 12 h @ July 7.

Scaled data results – Grower

Weekly report – example 2 weeks before harvestSite 2 example Irrigation at 16 hrs 2 x week (450 gal /tree)

02468

101214

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5:15

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lons

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7/20 to 7/26 SITE2 ALMONDSSensor 1 -Gallons

Sensor 2 -Gallons

Total Avrg Gallons

Weekly report –new Accumulator Sap Flow ChartSite 2 example Irrigation at 16 hrs 2 x week (450 gal /tree)

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0102030405060708090

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Gallons per Day Accumulated Sap Flow466 Gallons per tree 7/20 to 7/26

(Highest day 80gal, lowest 56 gal, avg 66 ) = 462 gal week

Total Accumulated Gallons

Sap Flow dataCIMISCalculate Kc wet days, Ks on

dryTwo Kinds – Crop Water Stress Index CWSI = (Etm- Eta)/Etm (Textbook

definition) Water “Stress Factor” CWSF = Ks/Kc So if Stress Factor = .75

Transpiration is 75 % of maximum T New terminology - simple for sap flow

Stress Data Analysis

ETo= Evapotranspiration potential based on weather models

Irrigation Model = Kc (Crop Coefficient) * ETo

to predict water use when well watered.

ETa (actual) = Ks * ETo , (and Ks=Eta / ETo)

Ks is Crop Water Stress Coeff. Typically lower than Kc.

Water cycleT = Transpiration

ETo Weather Stations Recommended

• CIMIS Type – • Example -

Dynamet • InteliMet

AdvantageSolar Radiation

(Pyranometer)

Air Temp and HumidityUltrasonic WindFlow or Water PressureBarometer

SAPIP - microclimate

Water Stress Index – Check the Irrigation ScheduleThen calculate the Kc

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0

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istu

re %

, Ho

urs

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ay

Site 1-2 Soil Moisture %, 5-10 cm (2-4 in)Soil Moisture % Site 1Irrigation hrsSoil Moisture % Site 2Irrigation Hrs

Ratio of Sap Flow / ETo = Crop Stress Coefficient

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0

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Sap Flow vs ETo CIMIS FSU Campus(mm) 12.7 mm = 1/2 in

Eto -Cimis

Eta -SF

Kc = 1.0 to 1.05

Note that the 28th and the 30th are low ET days. Cooler weather are not normally days to set Kc for July.

Ks after stress induced – 7 days before shaking 10 hrs @ Aug 57 hrs @ Aug 8

8/3/14 8/4/14 8/5/14 8/6/14 8/7/14 8/8/14 8/9/140

103.18 2.71

7.28 6.42 6.99 7.14 7.1

ET Accumulated(mm)/

Day Average 5.8 mm /day

235 Gallons applied; 305 gallons used, water reserve depletion 70 gal.

Manage Stress ? Yes, but… The two other varieties need longer to mature.

Irrigation for 28 Hours Aug 23-25

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Average Tree Transpiration – 21 gal / day.Surface Moisture ~ 10 % avg

Average Tree Transpiration – 14 gal / day.Surface moisture ~ 2%

Shaking alternate rows

8/29

Sap Flow data CIMIS Calculate Ks and Tracking Soil Moisture Sensors

Data from Puresense Capacitance Sensor – Delta-T portable sensor. SM150.

Pressure Chamber Independent Lab – Dellavalle

Project and relate to previous methods and history

Stress Data AnalysisValidation and Correlation

Did trees survive at Ks=.20 to .40 ? Stress was severe, and long, 30 days One Irrigation cycle 8/23 to 8/25 Stored water at 24 – 36 inches depleted in

stress.

Deep Roots provided survival water over 60 inch depth? One irrigation cycle over 4 weeks. Significant loss of leaves and stems noted.

Pressure Chamber Analysiso 5 trees each site measured 3-5 reps each

tree.o Mid – day stem water potential before stress

and after, over several weeks.o Followed U of C – guidelines ANR pub 8503

updated May 2014

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Site 1 –Always more stressed-10 to -12 Bar SWP is normal for well watered conditions.Site 2 –Seems less stressed,More vigorous.Sandy Soil has lower water content normally.- 7to -9 Bar is normal for well watered

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Stem Water Potential / Sap Flow Ks is highly correlated. Characterize the plant – varietal response vs. Soil, or vs. Grower special irrigator technique or root development

Put all correlations together.

Performed on benchmark days while well irrigated, and then during the “drought” started to dry down the nuts for harvest. Repeated SWP after recovery.

SITE 1 – SWP reached – 25 to -27 Bars (not shown)SITE 2 – SWP reached – 22 to -24 Bars (See Above)

Agrisensors.com Remote Logging Network Demo

Presentation

Computations

Graphics Server

User’s Records

Coming Soon:

New Server – Agrisensors.net

Growers Only Data Interface with Stress tools and Grower custom logs.

Automatic Integration of CIMIS data and outside weather sources.

New Server –Agrisensors.net

Look for Dynamax at the Almond Board Meeting Booth 905 for an update and demo - Dec 9.

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Summary:We hope you are satisfied that: Sap Flow demonstrated to track tree response to:Weather Water Status   Moisture level – and soil conditions  Competition –   Stress –   Detects Overwatering  Detect Under- Watering  Plant Recovery after Harvest Measure Kc (Crop Coefficient) after well watered Measures Ks (Stress Coefficient)

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• Info Benefits to Growers are:• Determine “Stress Factor” (Ratio of Ks/Kc) Directly and

Daily• Determine Stem or Leaf Water Potential Relationship to

Water stress – Field and Varietal Characterized• Know if Soil Water is Refilling Or in Depletion mode;• and by how much.

• Potentially a key measurement for :• Combine with other factors to determine Vigor• Combine with other factors to gauge production efficiency.• Measures Nutrient – Water Uptake Volume and Timing• Most Importantly Water Use Efficiency by week / month /

season !THANK YOU FROM DYNAMAX – PLEASE SEE US in the WET CENTER- NEXT DOOR  !