Ecological Security Assessment and Warning of Cultivated Land Quality in the Black Soil Region of Northeast China

The ecological security of cultivated land critically depends on maintaining the quality of the land under cultivation. For the security of the nation's grain supply, the evaluation and early warning of cultivated land quality (CLQ) are essential. However, previous studies on the assessment of the ecological safety of CLQ only rigidly standardized the assessment indicators and failed to investigate the positive and negative trends and spatiotemporal driving factors of the indicators. The main objective of this study was to develop a drive-pressure-state-response (DPSR) model to identify the hierarchical structure of indicators, using an improved matter-element model to assess the CLQ in the black soil region of northeastern China from 2001 to 2020. A panel data model was employed to explore the crucial drivers of CLQ warnings. The findings reveal that socioeconomic development has a potential impact on the improvement of CLQ. CLQ is generally in a secure state, with 69.71% of cities with no warnings and only 3.46% and 0.13% of cities under serious and extreme warnings, respectively. Compared with 2001, the CLQ in 2020 effectively improved by socioeconomic development and the conservation and reasonable utilization of arable land. According to the early warning results, the cultivated land in the northern regions was of higher quality than that in the southern regions. Moreover, the CLQ was significantly positively correlated with the agricultural GDP growth rate, grain yield per unit of cultivated land area, annual precipitation, and the habitat quality index, and was significantly negatively correlated with land carrying capacity. The findings of this study can provide a scientific and targeted basis for black soil conservation and utilization.