Based on the field survey data for 1216 apple growers in three provinces from China’s Loess Plateau Region, this paper adopted Multivariate Probit (MVP) model and intermediary effect model to analyze the influence mechanisms of digital technology adoption (DTA) on farmers’ choices of Fertilizer-reduction and Efficiency-improving Technologies (FETs) from the perspective of farmers’ cognition (FC). The correlation effects of three typical FETs of soil testing and formula fertilization, integrated water-fertilizer fertilization and slow/controlled release fertilizer, were tested empirically. The results showed that DTA could significantly affect the adoption of FETs by apple growers, and FC played a partial mediating role, and there were complementary effects among the three typical FETs. The results were further confirmed by the propensity score matching (PSM) robustness test and the instrumental variable (IV) endogeneity test conducted in the conditional mixed-process (CMP). The results of our heterogeneity analysis showed that the promotion effect of DTA on FETs in the group with junior high school education or below was more significant than that in the group with higher education, and the promotion effect was more significant in the group with large operation scale. Therefore, the improvement in Internet penetration should not be taken as the ultimate goal, but more attention should be paid to farmers’ mastery and effective use of DTA, promote the improvement in farmers’ cognitive level, and implement the “bundled” publicity and guidance strategy of FETs adoption, so as to help in the green transformation of agriculture.