Soil quality index of a crosby silt loam in central Ohio

• We assessed soil quality index using the scoring function analysis.
• The saturated hydraulic conductivity was the key soil physical indicator for SQI.
• The soil organic carbon was the key soil chemical indicator for SQI.
• The SQI was significantly correlated with corn yield.

Soil quality index (SQI) assessment is an important tool for evaluating land use and soil management practices in agroecosystems. Thus, the objectives of this research were to assess SQI using the scoring function analysis for different agricultural management practices, and to evaluate the effects of tillage and drainage systems on SQI of a crosby silt loam in central Ohio. Treatments included two tillage: no-till (NT), chisel tillage (CT), and two drainage factors: drainage (D) and no-drainage (ND). Three main steps were followed for the SQI assessment: (1) identification of the minimum data set of indicators, (2) indicator interpretation, and (3) integration of all indicator scores into one SQI value. The data showed that saturated hydraulic conductivity (Ksat) and soil organic carbon (SOC) concentration were the most discriminating and key indicator for SQI assessment. The SQI was not significantly affected by subsurface drainage treatment (D = 0.69 and ND = 0.70, P = 0.763). The results imply that long-term NT and subsurface drainage may not significantly alter the SQI because of the effects of weather condition, crop rotation, and weed-control. The SQI was significantly correlated with corn yield (R = 0.62, P < 0.05; n = 12), suggesting that the SQI is an effective and useful tool for assessing the agronomic productivity. The SQI computed by the method described is a useful tool to synthesize the soil and agronomic information.