Effects of Different Fertilization Methods on Root Distribution Characteristics of Korla Fragrant Pear

Objective Taking Korla fragrant pear as the research object, this study explored the effects of different fertilization methods on root spatial distribution and soil nutrient distribution in high-density pear orchards, so as to provide a theoretical basis for improving fertilizer use efficiency.

Methods Three fertilization treatments were set up: CK (alternate fertilization on both sides), T1 (unilateral fertilization for one consecutive year), and T2 (unilateral fertilization for two consecutive years). Root and soil samples were collected in areas with dense root distribution to determine root growth indices and soil nutrient indicators.

Results Treatment T2 significantly promoted the growth of absorptive roots, with the root-length proportion of absorptive roots reaching 79.81%. Root spatial-distribution analysis showed that T2 promoted root concentration in the fertilized zone. In the soil layer of 30 - 50 cm depth, the average root-length density, root-surface-area density and root-volume density were 0.36 mm·cm⁻³, 1.38 mm²·cm⁻³ and 0.59 mm³·cm⁻³, respectively. Spatial-distribution analysis of soil available nutrients indicated that T2 facilitated the enrichment of soil available nutrients near the fertilized zone, and nutrient contents peaked at the horizontal distance of 80 - 110 cm. Correlation analysis showed that soil available phosphorus content was significantly positively correlated with root-length density and root-surface-area density (P<0.05); soil available potassium content was also significantly positively correlated with root-volume density (P<0.05).

Conclusion Optimized fertilization methods can optimize the spatial distribution of root systems and improve the spatial matching capacity between roots and soil nutrients. Among them, unilateral fertilization for two consecutive years (treatment T2) exhibits particularly remarkable effects.