Abstract:To reveal the soil resource acquisition strategies of different pear varieties, this study focused on mature Korla fragrantr pear, Xinli No. 7 pear, and Yuluxiang pear in Xinjiang's intensive planting mode. We measured the fine root morphology and soil physicochemical properties at a distance of 30-210 cm from the trunk and a depth of 0-100 cm in 12-year-old pear orchards. The results showed that: (1) Korla fragrantr pear has the highest root length, root surface area, and root volume density, with fine root length density 1.53 and 2.23 times higher than Yuluxiang pear and Xinli No. 7, respectively; The ratio of root length and root surface area is as follows: Xinli No. 7>Korla Fragrant Pear>Yuluxiang pear, while the root tissue density is the opposite. Korla fragrantr pear roots were mainly distributed in the 20-80 cm soil layer, accounting for 81.04% of the root length, and as soil depth increased, the dense root area expanded continuously in the horizontal direction. Xinli No. 7 pear roots were mainly located in the 0-60 cm soil layer, with a root length ratio of 78.34%, and its horizontal root distribution was relatively uniform. Yuluxiang pear had a wide root distribution range without dense areas, and its root length density in the 80-100 cm deep soil was significantly higher than other varieties. (2) The nutrient content of soil in densely planted pear orchards was high and low, with high organic matter content in the soil at depths of 0-40 cm. The available nutrients generally decreased from the highest content area to both sides and deeper soil layers; The soil bulk density first increased and then decreased with the increase of soil depth, reaching its highest point in the 20-60 cm depth soil layer, while porosity, saturated moisture content, and field water holding capacity were the opposite. The root system of the densely planted pear orchard prioritizes the use of soil moisture near the trunk. After 15 days of flood irrigation, the soil moisture content at 50 cm, 100 cm, 150 cm, and 200 cm from the main trunk decreased by 6.53%, 5.06%, 1.71%, and 3.05%, respectively. (3) The fine root length density of Korla fragrantr pear and Yuluxiang pear was negatively correlated with soil organic matter and available nutrient content but showed a significant positive correlation with soil moisture content, indicating that soil moisture has a greater impact on the root distribution of Korla fragrantr pear and Yuluxiang pear. The fine root length density of Xinli No. 7 pear was significantly negatively correlated with soil depth and positively correlated with soil alkali-hydrolyzable nitrogen, showing a tendency towards nutrient acquisition. In conclusion, under the dense planting mode, the three pear varieties have different resource acquisition strategies, which are manifested in differences in fine root morphology and distribution. Korla fragrant pear had a high root system density, and fine roots expanded horizontally with increasing depth to improve resource acquisition efficiency. New Pear No. 7 tended to adopt an "acquisition" strategy, with its roots distributed in nutrient rich areas of the soil, exhibiting foraging characteristics. Yuluxiang pear tended to adopt a "conservative" strategy, occupying more soil space, increasing the proportion of deep soil roots, and enhancing its ability to use deep water.