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

BACKGROUND 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. RESULTS 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 (SQI(TDS)) and the SQI based on MDS (SQI(MDS)), and the spatial distribution of soil properties and SQI(TDS) showed a uniform pattern, except for Avail-N, Avail-B and SQI(MDS). 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. CONCLUSION 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. (c) 2021 Society of Chemical Industry.

Automated summary

The study evaluated the soil quality in pomelo orchards and found that mature orchards had higher soil quality index than young orchards. The study also identified unfavorable soil quality indicators such as soil acidification, high altitude, and deficiencies in certain nutrients, which are considered limiting factors for pomelo production. Integrated management practices including controlling acidification, reducing planting altitude, regulating fertilization, and monitoring soil properties are required for sustainable pomelo production.