Research on soil quality evaluation in an impermeable saline‐sodic soil with drip irrigation under cropping of Lycium barbarum L.

Quantitatively assessing the soil quality (SQ) of saline sodic soil is essential to understand the effects of improving methods and assistance for screening on efficient technologies. The objective of this study was to develop saline‐sodic SQ indices and evaluate the continuation of drip irrigation under film with salt‐enduring plant (wolfberry, Lycium barbarum L.) cultivation. 22 indicators (including characteristics of plant, soil, and restoration of vegetation) were collected from treatments with cultivation years of 1–11. Fourteen indicators showed significant relevance with improving duration and were selected as the potential SQ indicators. While electrical conductivity and Na + of saturation paste extract were exclusive for the values down to about 3 dS/m and 32 mmol/L in 3 years, respectively. It showed that the salt stress could be eliminated quickly after drip irrigation. A minimum data set (Ca 2+ , available phosphorus [AP], and pH) was obtained after principal component analysis. Four soil quality indices (SQIs) were computed, including linear scoring function with simple additive, non‐linear scoring function with simple additive, linear scoring functions with weighted additive, and non‐linear scoring functions with weighted additive. Results showed that simple additive SQIs were more sensitive than weighted additive SQIs for larger amplitude of variation. Both linear and non‐linear scoring functions based on simple additive method could provide an efficient and available model for SQ evaluation. The SQI increased slowly at initial amelioration stage (1–5 years) and then accelerated (>5 years). Additional methods to increase Ca 2+ and AP and decrease pH were advised.