The literature about how Information and Communication Technologies (ICTs) influence farmers’ adoption of sustainable agricultural technology is emerging, studies regarding the effects of particular smartphone-based digital extension services on farmers’ sustainable agricultural technology practices are limited. This study investigates the relationship between a digital extension service (“Zhe’ yang’ shi” WeChat application) and the adoption of soil testing and formula fertilization, a precision fertilization technology. A household choice model is constructed to explain the impact of the application. Based on a household-level data set from a survey of 400 farmers in Zhejiang in 2022, empirical results show that the use of the “Zhe’ yang’ shi” WeChat application significantly increases the adoption of soil testing and formula fertilization. We also discuss the heterogeneous effect by different production scales. The findings enrich the literature regarding ICTs’ influence on farmers’ behavior in adopting sustainable agricultural technology. It provides a valuable example for developing countries to promote sustainable agriculture through digital technology.

Improving farmers’ fertilization behavior through technical training is conducive to reducing agricultural non-point source pollution and maintaining soil health. The existing studies mainly discuss the impact of technical training on the adoption of soil testing formula fertilization (STFF) from the perspective of judging the training effect, but there are few further answers to how to improve the effect of technical training. Based on the theory of planned behavior and training transfer, this study adopted a logit model and OLS model to explore the role of training in the adoption of STFF, as well as the moderation effect of personalized information support. An empirical test was carried out using the survey data of farmers in Zhejiang Province, China. The results showed that participating in technical training is beneficial for farmers in adopting STFF, and receiving personalized information support can strengthen the promotion effect of technical training on the adoption of STFF. Further analysis reveals that there are certain differences in the above relationships among farmers with different operating scales. The findings could facilitate a deeper understanding of the improvement of technical training performance and accumulation of rural human capital and could also provide a useful reference for the policy formulation to optimize farmers’ fertilization behavior and promote sustainable agricultural development.