Fulvic Acid Fertigation Under Optimized Drip Irrigation Intervals Improves Soil Environment and Enhances Fruit Yield and Quality of Fragrant Pear Planted in Saline‐Alkali Land

ABSTRACT The effects of soluble organic amendments applied via drip irrigation on deep soil environment in salt‐affected orchards remain unclear. A 2‐year experiment was conducted in a Korla fragrant pear orchard to investigate the effects of irrigation interval (10, 15 and 20 days), fulvic acid (FA) application rate (0, 200 and 400 kg ha −1 ) and application timing (once or three times) on soil water content (SWC), salinity, NO 3 − ‐N content and thus fruit yield and quality. An insoluble organic amendment (CK) with equivalent organic carbon input to 400 kg ha −1 FA was included for comparison. The 15‐day interval increased SWC by 6% and 9% and decreased salinity by 9% and 14% compared with the 10‐ and 20‐day intervals, respectively. FA increased SWC and NO 3 − ‐N by 6%–15% and 8%–35%, respectively, reduced salinity by 8%–24% and outperformed CK at 400 kg ha −1 . Split FA application increased NO 3 − ‐N by 18%. Yield and fruit quality increased and then decreased with increasing irrigation interval but increased with FA rate and application frequency. Random forest analysis identified FA rate as the dominant factor affecting soil salinity. A 15‐day irrigation interval with 400 kg ha −1 FA applied three times is recommended for saline fragrant pear orchards in arid regions.