Soil resource zoning in Heilongjiang of China based on multi-dimensional super-volume ecological niche model

Black soil productivity and sustainable utilization can be one of the most important core strategies for national food security. However, long-term soil degradation has restricted the sustainable use of cultivated land in recent years. It is often required to implement site- and soil-specific measures for the protection of soil resources. Therefore, the zoning of arable land soil resources has been necessary for the precise conservation and utilization. Taking Heilongjiang Province as the research area, this study introduced the theory of multidimensional hyper-niche. An evaluation index system was constructed, suitable for the arable land soil resources. Two dimensions were selected: soil resource quality and soil sustainability. The actual and ideal niche were compared to determine the level at which the region’s arable land soil resources were required for protection and utilization. Additionally, a constraint index was also introduced to identify the influencing factors. A combination of suitability, constraint level, and constraint factors was identified as the zoning criteria. Differentiated measures were proposed using the resulting zones. The results show that the niche suitability of cultivated land soil ranged from 0 to 0.96. There was a high degree of alignment with the ideal ecological niche, with the spatiotemporal variations. The suitability increased from southwest to northeast in the western part of the province. Specifically, the high suitability was around the Songhua River in the east. While the low suitability was in the areas to the south, particularly in the southwest of Qiqihar and in Daqing City. There was the closely correlation with precipitation, alkalization, and severe erosion distribution. The moderate suitability was in the northeastern part of Jiamusi City, the central part of Shuangyashan City, and the central part of Mudanjiang City. There was also a correlation with the soil depth, acidification, precipitation, and irrigation conditions. In most areas, only localized conservation and utilization measures were required, along with adjustments to specific factors. The high soil quality constraint was in the east and west, while the sustainability constraint ranged from 0.042 to 0.314, and the low was from 0.044 to 0.638. The non-constrained areas of cultivated land soil resources were distributed at the junction and surrounding areas of Qiqihar and Heihe City. Alkalized areas were mostly distributed in the west of Heilongjiang Province, while the acidified areas were mostly in the southeast. Low-temperature areas were scattered in Heihe City with high latitude, and intense erosion occurred in the west of Daqing and Heihe City. Type Ⅰ-1 cultivated land accounted for 5.15%, which was distributed in Qiqihar, Daqing, Mudanjiang, Harbin, and Heihe City. Therefore, the significant constraints were the low ecological suitability of arable land resources, thus requiring conservation and sustainable use. A combined approach was involved for the low suitability and high constraints, particularly with deep plowing or deep burial of crop residues into the soil, plus increased application of organic fertilizer. This classification can provide a scientific basis for the differentiated protection and precise technical configuration of black soil resources in Heilongjiang Province.