Objective The Northeast Black Soil Region is the most important commodity grain production base in China, The farmland in this region faces significant issues, such as soil erosion, quality degradation and severe damage in cultivated land, which has a significant impact on China's food security. Therefore, there is an urgent need to assess the degree and spatial distribution of farmland degradation in the black soil region to identify key areas for protection and sustainable utilization.

Method Taking the typical black soil region in the Northeast as the research area, based on the scientific concept framework of Land Degradation Neutrality (LDN), land cover changes, farmland productivity, and soil organic carbon were selected as the main analysis indicators. The methods of simple linear regression and slope trend analysis were used to analyze the spatial and temporal changes of these indicators during the baseline period (2002-2008) and the assessment period (2009-2015), as well as the degree of farmland degradation in the typical black soil region of Northeast China was analyzed at a raster scale.

Result The proportion was 5.52% of the total farmland area, and the majority of them distributed in the southwest of Heilongjiang Province and the northwest of Jilin Province. The proportion of the restoration area was 6.90% of the total farmland area with the area was 1.23 × 10⁴ km²,which was primarily located in Inner Mongolia Autonomous Region, including Eerguna Right Banner and Chen Barag Banner, as well as Nenjiang, Wudalianchi, and Tonghe in Heilongjiang Province. During the assessment period, the total area of farmland degradation in the typical Northeast black soil region was approximately 0.96 × 10⁴ km², accounting for 5.32% of the total area. The restoration area was approximately 3.13 × 10⁴ km², accounting for 17.40% of the total farmland area. The improvement areas were mainly distributed in the southwest of Heilongjiang Province, including Gannan and Longjiang, as well as the northwest of Jilin Province, including Changling and Shuangliao. A small part was distributed in the northern part of Inner Mongolia, including Eerguna Right Banner and Chen Barag Banner.

Conclusion During the assessment period, the improvement area of farmland in the typical Northeast black soil region increased significantly compared to the baseline period, while the degradation area decreased significantly. Overall, the quality of farmland in the Northeast typical black soil region had improved. Through a comparative analysis of farmland degradation in the typical black soil region during the baseline and assessment periods, it was evident that the region achieved the goal of Land Degradation Neutrality from 2002 to 2015. This results could provide scientific evidence and technical support for preventing black soil quality degradation and promoting sustainable agricultural development.