A novel optimal data set approach for erosion‐impacted soil quality assessments—A case‐study of an agricultural catchment in the Chernozem region of Northeast China

Abstract

Because soil erosion is a primary cause of land degradation globally, it has received increasing attention in food production regions, such as the Chernozem region of Northeast China. This study assessed soil quality under soil erosion degradation using a novel optimal data set (ODS) approach and a comparative minimum data set (MDS) approach to derive soil quality indices (SQIs) within an agricultural watershed in Heilongjiang Province, China. The selection of SQIs was contingent on 15 physical, chemical, and microbial properties measured at 52 grids. Soil erosion rates were determined using the Cs‐137 technique. Results showed that SQIs derived from the ODS and MDS approaches were strongly correlated (r = 0.91, p < 0.01). However, soil quality inferred by SQIs varied significantly between erosion and deposition sites, namely, increasing from upstream to midstream to downstream areas. Changes in SQIs and erosion rates exhibited spatially opposing trends, reflecting the impact of soil erosion on soil quality, which was also confirmed by comparing representative soil properties at erosion and deposition sites. The ODS approach using the optimal fingerprinting factor screening procedure of the composite fingerprinting approach is a cause‐related method that uses a relatively strict indicator selection procedure, which mainly includes sample groupings, Kruskal–Wallis H test, discriminant function analysis, and conservative behaviour tests of factors. Thus, it can theoretically obtain more reliable results compared to MDS. Further studies are nevertheless needed to assess the feasibility of this novel approach in other cases.

Soil quality assessment of cropland in China and its relationships with climate and topography

“…As a result of the degradation of cropland, sustainable agriculture is threatened in China, negatively impacting local and global food security (Miao et al, 2011). Although some researchers have tried to assess the SQ of cropland on a regional scale (Nambiar et al, 2001; Teng et al, 2014; Tian et al, 2020; Wu et al, 2019; Zhang et al, 2022), such assessment on a national scale, to our knowledge, has never been attempted. Consequently, comparable quantitative data on cropland SQ on a national scale are lacking and important SQ‐related questions can at best be solved only in qualitative terms and based on national studies.…”

Long-term intensive management reduced the soil quality of a Carya dabieshanensis forest

“…The increased application of fertilizers stimulates plant growth, while also increasing their demand for P, which translates to the depletion of soil phosphate reservoirs if P is not added in time 44 . The removal of vegetation exacerbates soil erosion in woodlands, which may be another important driver for the reduction of soil P 9,26 . Furthermore, it is believed that the long-term application of chemical fertilizers reduces the organic matter content of soil, destroys its aggregate structures, and reduces porosity that leads to compaction 45 .…”

“…Fertilization and land use have been identified as the main causes of soil acidification 49 , the long-term application of N-based fertilizers leads to increased net outflows of nitrate via soil leaching and surface runoff, which exacerbates soil acidification 12 . Furthermore, the removal of understory vegetation reduces species richness and cover, aggravates surface soil erosion, and induces the loss of copious salt-based ions (Ca 2+ , Mg 2+ , K + , Na + ), which is another essential factor that cannot be ignored 12,26 . The evaluation of soil quality is an important aspect of forest management, which can assist managers with the planning of adjustments over time to improve productivity 18,24 .…”

“…The indicator screening and filtration rates can typically reach > 50%, which significantly saves the labor and time required for observations; thus, this lightweight evaluation strategy has been extensively recognized [21][22][23][24] . However, due to the complexity and heterogeneity of soil systems, further investigations are often required to evaluate the soil quality of different regions, various vegetation types, and diverse land management techniques 25,26 .…”

Evaluation of Soil Quality in a Composite Pecan Orchard Agroforestry System Based on the Smallest Data Set

“…As a tool for assessing the impacts of management measures and human activities such as land-use changes, soil quality assessments have attracted widespread attention [5,7,8]. They can assist with defining the status and dynamics of soil quality in a timely manner towards achieving the sustainable management of land resources [9]. Topsoil (0 to 20 cm) is a reliable indicator of the health of the soil as it is prone to disturbances.…”