Quantum Deep Learning Boosts Rice Yield Forecasting

By Dr Silpaja Chandrasekar, PhDReviewed by Susha Cheriyedath, M.Sc.Aug 18 2024

In a paper published in the journal Computers, researchers introduced a hybrid quantum deep learning (DL) model for rice yield forecasting. The model achieved impressive results by combining quantum computing’s feature processing with DL techniques, such as bidirectional long short-term memory (Bi-LSTM) for temporal extraction and extreme gradient boosting (XGBoost) for regression. This approach significantly enhanced prediction accuracy, aiding global agricultural planning and management.

Background

Past work has explored various methods for rice production forecasting, highlighting the importance of accurate predictions for resource allocation and food security. Complex, non-linear data presented challenges for traditional methods like autoregressive integrated moving averages (ARIMA) and regression models.

As a result, machine learning (ML) techniques like random forest (RF) and XGBoost were adopted. Recent advancements integrate DL models like LSTM and BiLSTM for feature extraction, often combined with classical methods for enhanced prediction. Quantum computing has introduced innovative approaches, like quantum feature processing, that enrich data representations and improve forecasting accuracy.

Model Development Summary

This research utilized datasets from the Food and Agriculture Organization (FAO) and the World Bank, focusing on crop yield, annual rainfall, pesticide use, and average temperature. According to preliminary studies, these parameters and crop yields have complicated, non-linear interactions that lack distinct linear patterns. The dataset, encompassing 3,270 records from 67 countries, might not fully capture global variations in rice production, suggesting the need for advanced modeling techniques. Temporal analysis showed significant fluctuations in yields, particularly in specific countries, indicating that DL models might be better suited for accurate predictions.

Additionally, the data's complexity and variability highlight the importance of integrating advanced methods to improve forecasting accuracy and account for global differences. This underscores the potential benefits of employing sophisticated models to better understand and predict agricultural trends. Moreover, utilizing state-of-the-art technology, including hybrid quantum-classical methods, may improve model performance and provide more detailed insights. This advancement in modeling could support more effective and sustainable agricultural practices.

Following the dataset analysis, the team developed a hybrid quantum-classical DL model. The preprocessing involved handling missing values, normalization using MinMax scaling, and one-hot encoding. A three-layer BiLSTM model with a thick layer was utilized to capture complicated temporal dependencies. Quantum feature processing was integrated to enhance data representation, using quantum circuits to explore complex feature interactions and create enriched features.

The analysts evaluated model performance using mean squared error (MSE), R², and mean absolute error (MAE). MSE measures the average squared error between predictions and actual values, R² assesses the model's explanatory power compared to a mean-based model, and MAE provides the average magnitude of errors without bias toward any direction. These metrics collectively ensure a thorough evaluation of the model's accuracy and predictive performance.

Data Preparation Results

This research utilized Python, the pennylane quantum simulator, and Google Colab, with local hardware including an Intel Core i7-1165G7 central processing unit (CPU) and 16GB of memory. Initial dataset analysis revealed issues with the dataset, including duplicate and missing records. Specifically, from the original 3,270 records, 297 were identified as duplicates or missing values and removed, leaving 2,973 records. Removing these inconsistencies aimed to improve dataset quality by reducing potential biases and ensuring more reliable and accurate model training.

After preprocessing, the dataset was ready for ML, which comprised one-hot encoding and normalization. Normalization was applied to numerical values before one-hot encoding, transforming categorical features into binary columns, such as nation names. This approach ensures that numerical features are appropriately scaled while maintaining the integrity of categorical data. One-hot encoding transformed the "Area" column into a series of binary columns representing individual countries, thereby facilitating effective processing by ML algorithms.

Five distinct dataset segments served as a validation set, while the remaining four were used for training. The team used MSE, R², and MAE to measure performance indicators, reporting the average values of these metrics. A scatter plot of the regression results also illustrated predictions against actual values. The plot revealed that predictions are closely aligned with actual values, indicating strong model performance.

The scatter plot demonstrates that predictions for each fold are generally near the identity line, suggesting accurate results. The close alignment of the points with the line reflects positive prediction accuracy. This visual assessment is corroborated by the MSE, MAE, and R² metrics, highlighting the model's effectiveness and robustness in making accurate predictions.

Conclusion

To sum up, this research successfully developed a hybrid quantum DL model for rice production forecasting, significantly improving prediction accuracy over traditional methods. Integrating quantum features with BiLSTM and XGBoost regressor models enhanced data representation and performance metrics like MSE, R², and MAE.

Despite challenges with current quantum technology and high computational demands, the study highlighted the potential of quantum computing in agronomic forecasting. The findings suggest that further exploration and adoption of this hybrid approach could optimize agricultural decision-making and contribute to global food production and sustainability.