Effects of microbial fertilizer and green manure cropping systems on fruit quality of Korla fragrant pear

TL;DR

This study explores how microbial fertilizer and green manure cropping systems affect the quality of Korla fragrant pears by improving soil and fruit nutrients, though some treatments reduced flavor compounds.

Contribution

The study introduces a novel approach combining microbial fertilizer and green manure to enhance pear quality and soil health in a monoculture system.

Findings

Green manure and microbial fertilizer improved soil properties and fruit mineral content.

CM1 treatment showed the greatest improvement in soil and fruit nutrients.

Reduced zinc content in treatments led to decreased volatile organic compounds in fruit.

Abstract

Korla Fragrant Pear(Pyrus sinkiangensis Yu), a high-value Geographical Indication product from Xinjiang, China, faces declining fruit quality due to soil degradation from intensive monoculture. This study investigated microbial fertilizer (JF) and green manure (oil sunflower - DK1, DK2; sweet clover - CM1, CM2) intercropping in a pear orchard to improve soil and fruit quality, compared to conventional fertilization (CK). Comprehensive analyses assessed soil properties, fruit minerals, metabolites (monosaccharides, fatty acids, amino acids), and volatile organic compounds (VOCs).Both JF and green manure treatments improved soil physicochemical properties, with CM1 showing the greatest effect. Treatments JF, CM1, CM2, DK1, and DK2 significantly increased fruit K, P, Fe, and Mn content but significantly decreased Zn content. JF significantly enhanced monosaccharide accumulation, while CM1 and high-density oil sunflower (DK2) notably increased fatty acid and free amino acid content. However, all treatments (JF, CM1, CM2, DK1, DK2) significantly reduced total fruit VOCs. Correlation analysis indicated fruit Zn content was positively correlated with most VOCs. Reduced Zn inhibited alcohol dehydrogenase (ADH) and copper-zinc superoxide dismutase (Cu/Zn SOD) activity, leading to decreased VOC synthesis. Therefore, while CM1 is recommended as the optimal strategy for improving basic nutritional quality and soil fertility, coordinated zinc nutrition management is essential when implementing green manure to balance nutritional enhancement with maintaining characteristic flavor, ensuring sustainable industry development.

Figures