Leaf Removal Enhances Tuber Yield in Jerusalem Artichoke by Modulating Rhizosphere Nutrient Availability

Leaves, as the primary “source” organ for photosynthesis, directly influence plant yield. However, it remains unclear whether leaf removal affects Jerusalem artichoke yield by altering rhizosphere nutrient availability. This study evaluated the effects of different leaf removal intensities on tuber yield and rhizosphere nutrient characteristics of Jerusalem artichoke (Helianthus tuberosus L.). Results from two consecutive field experiments demonstrated that removal of the lower leaves (Q2) significantly increased tuber yield in both years, with gains of 93.7% in 2022 and 282% in 2023 compared with the control. Although other leaf removal treatments also showed yield increases, these were not statistically significant. Principal component analysis revealed that rhizosphere soils associated with tubers and taproots contained higher concentrations of ammonium nitrogen, nitrate nitrogen, available phosphorus, and available potassium than bulk soils. Among these nutrients, tuber yield was significantly and positively correlated with available potassium (r = 0.57). These findings indicate that moderate removal of lower leaves enhances rhizosphere nutrient conditions and promotes higher tuber yield in Jerusalem artichoke.