Soil chemical quality assessment and spatial distribution of pomelo orchards in acidic red soil hilly regions of China.

Abstract

Soil quality assessment is a critical strategy for determining optimum fertilization in intensive pomelo production. In this study, we evaluated the soil quality status and mapped the spatial distribution of 347 soil samples collected from pomelo orchards in Pinghe County, southern China. We analyzed nine chemical parameters and an altitude indicator. The mean soil quality index (SQI) was 0.355 in the total data set (TDS) and 0.292 in the minimum data set (MDS). Available Ca (Avail-Ca), pH value, organic matter and altitude were selected as indicators of soil quality in the MDS. The SQI in mature orchards (>10 years) was higher than that in young orchards (<10 years), while no differences between soil types and altitude gradients were identified. We detected a significant positive correlation between the SQI based on TDS (SQITDS ) and the SQI based on MDS (SQIMDS ), and the spatial distribution of soil properties and SQITDS showed a uniform pattern, except for Avail-N, Avail-B and SQIMDS . Overall, unfavorable soil quality indicators, including rich in Avail-P, deficient in Avail-Ca, -Mg and -B, soil acidification and high altitude, were considered to be limiting factors for pomelo production. The soil chemical quality in pomelo orchards is generally low, indicating that integrated management by controlling acidification, reducing planting altitude, regulating fertilization and monitoring soil properties is required for sustainable pomelo production. © 2021 Society of Chemical Industry.