Background As a critical national grain production base, the Northeast China plain has experienced intensified soil erosion in recent years. This leads to the loss of soil nutrients and degradation of soil quality, posing a direct threat to national food security. However, the specific extent of multi-nutrient loss from the soil caused by erosion in the upland soils of the Northeast China plain remains unclear. Furthermore, identifying which areas characterized by specific erosion intensities require prioritized attention and protective measures is an urgent research need.

Methods Utilizing the RUSLE model integrated with GIS-based spatial analysis, this study analyzed the spatial variation characteristics of mean soil erosion intensity and associated 0–30 cm soil nutrient loss fluxes (including SOC, TN, TP, and TK) in drylands across the contiguous Liaohe, Songnen, and Sanjiang plains during 2010—2018. We further elucidated the mechanistic controls of soil erosion spatial heterogeneity on multi-nutrient depletion patterns.

Results 1) Soil erosion was primarily characterized as slight, with the following ranking of erosion intensity: Liaohe plain > Songnen plain > Sanjiang plain. Moderate to severe erosion was mainly distributed in the central, western and southern parts of the three sub-plains. 2) SOC and TN of dryland in the Northeast plain increased from the southwest to the northeast, TP increased from the center to the surroundings, and TK decreased from the center to the surroundings. The content of SOC, TN and TP in the three sub-plains was in the order of Sanjiang plain > Songnen plain > Liaohe plain, whereas the content of TK was in the order of Songnen plain > Sanjiang plain > Liaohe plain. 3) The total loss of SOC, TN, TP and TK was 2.95 × 10⁷ t, 3.24 × 10⁶ t, 1.67 × 10⁶ t and 6.24 × 10⁷ t respectively. With the intensification of erosion, the average loss per unit area of each nutrient showed a significant increasing trend in the three sub-plains, while the total loss of each nutrient exhibited a trend of initial increase, followed by a decrease, and then a sharp increase. The total loss of each nutrient was the largest in the area of severe erosion, followed by that in the area of slight erosion. The contradiction of "low content-high loss" of soil nutrients appeared in the Liaohe plain.

Conclusions This study quantified multi-nutrient losses from erosion in the Northeast plain’s upland soils, elucidating the impact of spatial variability in soil erosion on multi-nutrient loss. It identified priority control zones—severe and slight erosion areas across its three sub-plains—with very severe erosion zones in the Liaohe plain demanding urgent intervention. These findings provide a scientific foundation for effective soil resource management and sustainable conservation in the region.