A dual measurement-modelling approach for water-use optimization in apple orchards in New Zealand

Paolo Zuccarini

Aim of the work

• To assess the impact of apple production on water quantity and quality; measure-model approach

• Key data: field + data mining• Soil Plant Atmosphere System Model (SPASMO)

(Green and Clothier, 1995; 1999): assessments and predictions. Hydrological Balance of apple orchards and Water Footprint of apple production

Water footprint

WFP calculation methods

• Water consumptive method (WFN)

• Full hydrological method (Plant and Food Research)

Water Consumptive

Method

Simple and straightforwardDoes not account for:- Rainfall to the Green Pool- Dr e Ro to the Blue Pool

X

Full Hydrological Method

Soil Plant Atmosphere System Model (SPASMO) (Green and Clothier, 1995; 1999)

Methodology

Site location:The Heretaunga

Plains of Hawke’s Bay

Methodology

• Field Data Collection:

Sap Flow:Heat-pulse sensors.

Blue and green water contribution to tree transpiration will be modelled

• Soil Water Content with TDR: 0.0 – 1.0 m

• PAR radiation on orchard floor to deduce changes in green leaf area

Methodology

Methodology• Drainage: passive-wick tension fluxmeters (1.2 m)

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100

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Dec Feb Apr Jun Aug Oct Dec

Cum

ulati

ve N

O3

loss

[kg/

ha]

Cum

ulati

ve d

rain

age

[mm

]Drainage NO3 loss

- Blue water recharge- Leaching losses of nitrogen

Methodology

Database data collection

• Irrigation usage by Fruition Horticulture

• Weather patterns (40 years) by VCNS of NIWA

• Functional Soil Layers (FSL) by Landcare’s Research

Methodology• Data will be introduced in SPASMO to perform the hydrological balance and WFP assessment

• Water flows according to the hydrological approach:

• Rainfed• Gi

R = (P – PL) – (DR + RR) P: climate station DR, RR: fluxmeters

• GoR = (TC

R + ESR) TC

R: heat pulse technique ESR: TDR

• Green WF = GFPR = ΔGR * 10 / YR

• BiR = (DR + RR) DR, RR: fluxmeters

• BoR = 0.0 I: data on irrigation (che qui è 0.0)

• Blue WF = BFPR = ΔBR * 10 / YR

• XFPR = DR * (CR – Cn)/(Cr – Cn) * 10/YR CR: SPASMO prediction Cr, Cn: standard values

• • Irrigated• Gi

I = (P – PL) – (DR + RR) P: climate station DR, RR: fluxmeters

• GoI = (TC

R + ESR) TC

R: heat pulse technique ESR: TDR

• Green WF = GFPI = ΔGI * 10 / YI

• BiI = (DI + RI) DI, RI: fluxmeters

• BoI = I I: data on irrigation

• Blue WF = BFPI = ΔBI * 10 / YI

• XFPI = DI * (CI – Cn)/(Cr – Cn) * 10/YI CI: SPASMO prediction Cr, Cn: standard values

Expected Results

Detailed Water Balance Assessment of apple orchards

Expected Results

Water footprint assessment for apple production

Consumptive Approach Full Hydrological Approach

Expected ResultsWater component Goal Strategies Practical Methods Measurements Techniques of

measurement

Green Water

Reducing plant transpiration

Limiting vegetative vigour

-Pruning-Leaf plucking-Deficit irrigation

-Sap flow-Gas exchanges

-Heat pulse technique-Porometer (if available)

Reducing soil evaporation

Types of interline soil plant coverage TDR

Blue Water Reducing irrigation

Ameliorating soil water storage capacity

Tillage strategies Soil water retention

TDR measurements,Retention curves

Optimizing irrigation Deficit irrigation? The data on

irrigation

Technical data on irrigation volumes

Optimizing plant water uptake ? Sap flow

-Heat pulse technique-TDR

Grey WaterReducing leaching and drainage of agrochemicals

-Soil compaction-Deficit irrigation-Low inputs

-Drainage and leaching-[NO3]leachate

Fluxmeter(Gee et al., 2009)

ApplicabilityCalculation of Irrigation requirements

ApplicabilityWFP Assessment

ApplicabilityTo our climate

soils crops

Thank You!