Study on climate suitability for maize and technical implementation strategies under conservation tillage in Northeast China

Conservation tillage is an effective planting system that balances land conservation with utilization. However, its indiscriminate promotion may lead to issues such as delayed maize germination, reduced yields, and soil structure deterioration. Previous studies have primarily focused on the impact of climate change on the climate suitability for maize cultivation in Northeast China, with little consideration of how changes in soil moisture and temperature due to conservation tillage affect maize climate suitability. Moreover, there is a lack of targeted conservation tillage implementation strategies that consider the specific characteristics of different regions. Therefore, this study quantifies the impact of conservation tillage on soil moisture and temperature, using these factors as environmental variables. The MaxEnt model was applied to simulate maize climate suitability under conservation tillage in the black soil region of Northeast China. Additionally, the study innovatively extracted typical topographic and geomorphological features of the region and proposed region-specific conservation tillage implementation strategies. The results indicate that: (1) Conservation tillage significantly impacts soil moisture and temperature. When straw coverage reaches 30 % to 95 %, soil moisture increases by 0.04–0.13 m³ /m³ , while soil temperature decreases by 0.15–0.46°C, thereby influencing the distribution of maize climate suitability. (2) Between 2000 and 2020, the area of climate suitability for maize under conservation tillage in Northeast China has shown an upward trend, increasing by 12.6 × 10⁴ km², with an average suitable area of 96.2 × 10⁴ km². (3) The area suitable for promoting straw mulching no tillage technology is 47 × 10⁴ km², accounting for 48.8 % of the total suitable area. The area suitable for implementing high stubble ridge side planting technology is 24 × 10⁴ km², making up 25 % of the total suitable area. The area suitable for promoting straw mulching ridge tillage with minimal tillage technology is 10.9 × 10⁴ km², accounting for 11 % of the total suitable area. The area suitable for implementing high stubble inter-row direct seeding technology is 8.6 × 10⁴ km², making up 9 % of the total suitable area. The results of this study provide theoretical support for the scientific promotion and region-specific implementation of conservation tillage, which is of great significance for achieving coordinated improvement of grain production and farmland conservation.