Single Technology or Technology Combinations? The Impact of Soil Improvement Technology Use on Farmers’ Fertilizer Use

Fertilizers play a crucial role in increasing grain yields and ensuring agricultural supply. However, heavy reliance on fertilizers has brought growing pressure on food security and environmental sustainability. Soil improvement technologies provide an effective way to reduce fertilizer use while maintaining agricultural productivity. This paper uses survey data from 808 farmers in China’s major grain-producing regions. It examines the effects of single and combined soil improvement technologies on fertilizer application intensity. Based on farmers’ capabilities, cognition, and production behaviors, this study further explores the moderating roles of digital literacy, psychological expectation, and continuous technology adoption. The results show that technology combinations have a stronger inhibitory effect on fertilizer reduction than a single technology. Digital literacy and continuous technology adoption strengthen this mitigation effect, while psychological expectations weaken it. The fertilizer-reduction effect is more evident in larger farms, non-transferred land, and farms with higher levels of mechanization. Future agricultural policies should place more emphasis on the popularization of technology combinations, such as through targeted subsidies and special supporting funds. At the same time, differentiated support measures should be formulated in light of local conditions to curb excessive fertilizer application and promote the sustainable development of agriculture.