Winter wheat yield estimation at the field scale using sentinel-2 data and deep learning

Abstract

Accurately expressing the spatial pattern of crop yield at a sizeable regional field scale is paramount for precision agriculture. However, the current methodologies consistently face numerous challenges, comprising inadequate yield samples and algorithmic tendencies to underestimate higher yield values and overestimate lower ones. Data-driven deep learning algorithms effectively transform remotely sensed data into high-dimensional feature representations. Developing a cost-efficient model that minimizes the impact of insufficient field samples while maximizing the representation of crop yield differences on plots is worthwhile. The study developed an ACNN (Attention-based One-dimensional Convolutional Neural Network) model to efficiently extract and optimize the spatiotemporal features of winter wheat yield from Sentinel-2 MSI Level-2A data while relatively reducing the model's reliance on training samples. Winter wheat yield at both county and field scales in Henan Province was estimated utilizing Random Forest (RF), Convolutional Neural Network (CNN), and the ACNN models. The proposed ACNN model effectively identified key phenological stages and discerned noteworthy spectral bands essential for field-scale winter wheat yield estimation. It underscores the heading stage as a pivotal period influencing yield formation, emphasizing the indispensable contributions of the B8 (835.1 nm) and B12 (2202.4 nm) spectral bands in yield estimation. Moreover, this model adeptly overcame the challenge of underestimating higher values and overestimating lower values in crop yield estimation while showcasing robust generalization ability. The study presents a practical method for field-scale crop yield estimation over a large area with insufficient yield samples.