Soil quality should be accurate evaluated at the beginning of lifecycle after land consolidation for eco-sustainable development on the Loess Plateau

Abstract Evaluating farmland soil quality and zoning the obstacle factors regions were essential to enhance the productiveness of cultivated land and adopt sustainable management practices after land reclamation. The land consolidation project was initiated to reclaim gullies of the Loess Plateau and return them to farmland. However, soil quality and eco-sustainable improvement strategies of the reclaimed farmland were still unknown. The primary objective of this research was to assess soil quality, select a suitable evaluation method and provide precise amendment recommendations for this regions, selecting the reclaimed farmland of Yan’an city as a case. Indictor values of SOM, CEC, nitrogen, phosphorus, avail -Mn and -Zn on reclaimed farmland were considered at low level and soil quality was generally poor. A minimum data set evaluation method selecting by the Norm values is recommended for delineating poor quality farmland, with the threshold values of soil quality at 0.92. The main limiting factors for reclaimed farmland were identified as SOM, CEC, nitrogen, NaHCO3-P, and enzyme activities. SOM and nitrogen content, CEC and clay percentage, and NaHCO3-P concentration were the main limiting factors of soil quality on the all Yan’an regions, northern and southern areas, respectively, indicating the soil texture should be improved in the arid areas while the phosphate fertilizer should be accurately applied in the semi-arid regions. Those approaches will identify areas needing more intense management and improve utilization of applied amendments. We emphasize the spatial distribution of limiting factors was uneven on the Loess Plateau regions and the particular attention should be paid on specialized soil quality evaluation of targeted regions for precise amendment and utilization. The results of this study are important at the practices for avoiding the traditional unsustainable and inaccurately fertilization strategy.