Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt

Understanding the causes of spatiotemporal variation in crop yields across large areas is important in closing yield gaps and producing more food for the growing global population. While there has been much focus on using data-driven models to predict crop yield, there is also an opportunity to use...

Full description

Saved in:
Bibliographic Details
Main Authors: Patrick Filippi, Brett M. Whelan, Thomas F. A. Bishop
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Agriculture
Subjects:
Online Access:https://www.mdpi.com/2077-0472/14/12/2318
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850049730748350464
author Patrick Filippi
Brett M. Whelan
Thomas F. A. Bishop
author_facet Patrick Filippi
Brett M. Whelan
Thomas F. A. Bishop
author_sort Patrick Filippi
collection DOAJ
description Understanding the causes of spatiotemporal variation in crop yields across large areas is important in closing yield gaps and producing more food for the growing global population. While there has been much focus on using data-driven models to predict crop yield, there is also an opportunity to use these empirical models to understand which factors are driving variations in yield and to quantify their contributions. This study uses a large database of 625 rainfed wheat yield maps from 14 different seasons (2007–2020) across the eastern grain belt of Australia. XGBoost models were used, with predictors including maps of soil attributes (e.g., pH and sodicity), along with weather indices (rainfall, frost, heat, growing degree days). The model and predictors could accurately predict field-scale yield, with a Lin’s concordance correlation coefficient (LCCC) of 0.78 with 10-fold cross-validation. SHapley Additive exPlanation (SHAP), a form of interpretive machine learning (IML), values were then used to assess the impact of the variables on yield. The SHAP values for each predictor were also mapped onto a grid of the study area for the 2020 season, which showed the impact of each predictor on wheat yield (t ha<sup>−1</sup>) and revenue (AUD ($) ha<sup>−1</sup>) in interpretable units. Weather variables, such as rainfall and heat events, had the largest impact on yield. Although generally less significant, soil constraints such as soil sodicity were still important in driving yield. The results also showed that despite their largely temporally stable nature, soil constraints impact yield differently, depending on seasonal conditions. Overall, data-driven models and IML proved valuable in understanding the impact of important weather and soil variables on wheat yield and revenue across the eastern Australian grain belt. This could be used to determine the magnitude and economic impact of soil constraints and extreme weather on crops across regions and to inform policies and farm management decisions.
format Article
id doaj-art-e34079d1534b4fe681b99a5dbec6574a
institution DOAJ
issn 2077-0472
language English
publishDate 2024-12-01
publisher MDPI AG
record_format Article
series Agriculture
spelling doaj-art-e34079d1534b4fe681b99a5dbec6574a2025-08-20T02:53:39ZengMDPI AGAgriculture2077-04722024-12-011412231810.3390/agriculture14122318Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain BeltPatrick Filippi0Brett M. Whelan1Thomas F. A. Bishop2Precision Agriculture Laboratory, Sydney Institute of Agriculture, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW 2006, AustraliaPrecision Agriculture Laboratory, Sydney Institute of Agriculture, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW 2006, AustraliaPrecision Agriculture Laboratory, Sydney Institute of Agriculture, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW 2006, AustraliaUnderstanding the causes of spatiotemporal variation in crop yields across large areas is important in closing yield gaps and producing more food for the growing global population. While there has been much focus on using data-driven models to predict crop yield, there is also an opportunity to use these empirical models to understand which factors are driving variations in yield and to quantify their contributions. This study uses a large database of 625 rainfed wheat yield maps from 14 different seasons (2007–2020) across the eastern grain belt of Australia. XGBoost models were used, with predictors including maps of soil attributes (e.g., pH and sodicity), along with weather indices (rainfall, frost, heat, growing degree days). The model and predictors could accurately predict field-scale yield, with a Lin’s concordance correlation coefficient (LCCC) of 0.78 with 10-fold cross-validation. SHapley Additive exPlanation (SHAP), a form of interpretive machine learning (IML), values were then used to assess the impact of the variables on yield. The SHAP values for each predictor were also mapped onto a grid of the study area for the 2020 season, which showed the impact of each predictor on wheat yield (t ha<sup>−1</sup>) and revenue (AUD ($) ha<sup>−1</sup>) in interpretable units. Weather variables, such as rainfall and heat events, had the largest impact on yield. Although generally less significant, soil constraints such as soil sodicity were still important in driving yield. The results also showed that despite their largely temporally stable nature, soil constraints impact yield differently, depending on seasonal conditions. Overall, data-driven models and IML proved valuable in understanding the impact of important weather and soil variables on wheat yield and revenue across the eastern Australian grain belt. This could be used to determine the magnitude and economic impact of soil constraints and extreme weather on crops across regions and to inform policies and farm management decisions.https://www.mdpi.com/2077-0472/14/12/2318yield modellingempiricalXAIexplainable AIsoil constraintsfrost
spellingShingle Patrick Filippi
Brett M. Whelan
Thomas F. A. Bishop
Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
Agriculture
yield modelling
empirical
XAI
explainable AI
soil constraints
frost
title Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
title_full Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
title_fullStr Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
title_full_unstemmed Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
title_short Explainable Machine Learning to Map the Impact of Weather and Soil on Wheat Yield and Revenue Across the Eastern Australian Grain Belt
title_sort explainable machine learning to map the impact of weather and soil on wheat yield and revenue across the eastern australian grain belt
topic yield modelling
empirical
XAI
explainable AI
soil constraints
frost
url https://www.mdpi.com/2077-0472/14/12/2318
work_keys_str_mv AT patrickfilippi explainablemachinelearningtomaptheimpactofweatherandsoilonwheatyieldandrevenueacrosstheeasternaustraliangrainbelt
AT brettmwhelan explainablemachinelearningtomaptheimpactofweatherandsoilonwheatyieldandrevenueacrosstheeasternaustraliangrainbelt
AT thomasfabishop explainablemachinelearningtomaptheimpactofweatherandsoilonwheatyieldandrevenueacrosstheeasternaustraliangrainbelt