Ehud STROBACH, Yotam MENACHEM,

Avimanyu RAY, Roi BEN-DAVID

Agricultural Research Organization

Soil, Water and Environmental Sciences

Seasonal Predictions of Crop Yield under Changing Climate Conditions:

The Coupled Crop-Climate Modeling Approach

Wheat in Israel

• Spring wheat that is grown in the winter (October-May)
• About half is harvested early (around February) for fodder
• Mostly clustered in the Northern Negev
• High sensitivity to climate (mostly dryland agriculture)

Why should we want seasonal predictions of wheat yield?

• Inform farmers, policy makers, and stakeholders about potential risks
• Apply climate-informed management strategies:
• Wheat cultivars
• Sowing and harvest dates
• Fodder (silage/hay) or grain
• Irrigation
• Rotation

Climate models

4

• Domain – the location where predictions are made.
• Dynamical core - equations describing the thermodynamics and fluid dynamics of the model.
• Parameterizations (physics) - approximations for processes that can not be represented directly in a model because they are either too small scale, too complicated or not well understood.

Seasonal prediction systems

Johnson et al. 2019 (Geoscientific Model Development)

• Seasonal prediction systems have potential prediction skill arising from the slow varying process in the ocean and the land surface
• Operational forecasts are currently performed at low horizontal resolution (~0.5^◦)

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Israel’s topography and rain

• Complex topography
• Sharp precipitation gradients: north-south and west-east

Crop model: Noah-MP-Crop

Hypotheses

• A downscaled seasonal prediction system can improve regional climate predictions
• A coupled climate-crop model can further improve prediction skill and provide reliable seasonal predictions of crop yield

Tasks

• Determine Noah-MP-Crop parameters for local spring wheat grown in Israel
• Perform coupled climate-crop model simulations forced by a seasonal prediction system

Objective

Develop a high-resolution coupled climate-crop seasonal wheat yield prediction system for Israel

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Field experiments

Model parameters assessment

LAI and rain

• Irregular rains characterized the season
• Large dependency of the emergence date on rainfall

Received one irrigation on Dec 12

Phenological stages

• GDD can predict the development stage of different fields sown at different times
• BH and Yashan-5 show slower development

Phenological stages

BH froze its development for about a month

Biomass partitioning – total biomass

Leaf weight

Steam weight

Spike weight

Biomass partitioning – fractional biomass

Preliminary results – coupled simulation

• Model: WRF
• 2013-2014
• Sowing date: November 1^st
• Boundary and initial conditions for ERA5

Summary and future work

• First year (out of three) of wheat sampling has just ended, parameters for the NoahMP-Crop are now being extracted
• Under typical conditions (no water and heat stress), GDD can predict the phenological stage of wheat in Israel
• Using crop model parameters based on literature search, the WRF-NoahMP-Crop simulation forced with observed conditions (ERA5) can reproduce wheat yield to first order

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• Two more years of field sampling are planned
• WRF-NoahMP-Crop simulations forced with a seasonal prediction system

What knowledge gaps are there in the worlds of precision agriculture and AI in your field of expertise?

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• Missing high-resolution frequently-updated soil and vegetation data for model initialization
• Accurate model representation of the complex plant’s growth processes and its interaction with the environment.

Choose one knowledge gap from the below list and add it to the concluding slide: of your presentation:

• What relevant project would you like to focus on, and why?

Generation of regional high-resolution soil and vegetation data assimilation system updated at sub daily frequency, using input data from soil networks and satellite observations.

• What is the global impact potential of this project?

Maps of soil and vegetation will improve the initialization of climate model and, by that, advance forecast quality of seasonal crop development and yield.

• What is needed for this project to happen? (experts in other fields (which?), funding, technology,

Funding and experts from other fields

Full Name: Ehud Strobach

Affiliation: Agricultural Research Organization

Institute of Soil, Water and Environmental Sciences

Department of Environmental Physics and Irrigation

Contact Information: udist@volcani.agri.gov.il