Suitability evaluation and driving factors analysis of conservation tillage in typical black soil areas: a case study of Shenyang City

Conservation tillage is of great significance in improving the quality of drylands in Northeast China's black soil and protecting the ecological environment. However, there is still limited research on constructing a suitability evaluation index system for drylands conservation tillage at the regional scale, conducting scientific evaluations, and establishing priorities. Shenyang City is located in the hinterland of the southern edge of the black soil in Northeast China, with dry land accounting for 77% of the cultivated land area. It is an important commodity grain base in Liaoning Province. Clarifying the suitable areas and priority of drylands conservation tillage is particularly crucial for the protection of cultivated land in this region, and also provides important basis for the implementation of conservation tillage technology. Taking the drylands in Shenyang City as the research object, the Analytic Hierarchy Process and Delphi method were used to construct a suitability evaluation index system for 9 indicators including effective accumulated temperature, annual precipitation, average wind speed, terrain location, slope, plot regularity, cultivated land, effective soil layer thickness, and organic matter from three aspects: climate conditions, topography, and soil properties. GIS technology was used to evaluate the suitability of protective tillage in drylands and conduct spatial analysis. By calculating the obstacle degree of each indicator, the main influencing factors were identified. The suitability of conservation tillage in drylands in Shenyang city shows a trend of high in the west and low in the east, and high in the south and low in the north. The areas of high suitability, relatively suitability, general suitability, and unsuitability account for 28.24%, 27.36%, 31.24%, and 13.16% of the drylands area, respectively. From the perspective of obstacle levels in each subsystem, the obstacle level of climate conditions is 45%, the obstacle level of terrain and landforms is 33%, and the obstacle level of soil properties is 22%. Among them, indicators such as annual average precipitation, effective accumulated temperature, slope, and effective soil layer thickness are the core driving factors. Overall, climate factors are the main factors affecting the layout of conservation tillage in arid fields in the region. The suitability of conservation tillage in arid fields in the western and southern parts of Shenyang is relatively high, and conservation tillage techniques can be prioritized for practical implementation; However, the suitability of carrying out drylands conservation tillage in the eastern and northern regions is relatively low, and more suitable technical models can be explored for protection, thereby achieving the conservation and improvement of drylands quality in the entire region.