Abstract:

Continuous cropping (CC) of Pinellia ternata (Thunb.) Breit results in soil degradation and extended periods of rotation restoration. To mitigate these challenges, we integrated green manure into the crop rotation system. A 5- year field trial evaluated the following five treatments: 2 years of wheat rotation (CY2C), 2 years of wheat with one green manure crop (CY2GC), 3 years of wheat rotation (CY3C), 2 years of wheat with two green manure crops (CYGYGC), and continuous P. ternata planting (CC). The results indicated that the plant height of the CYGYGC treatment increased by 204.64% compared with the CC treatment, and the leaf area increased by 223.14%, with no significant difference from the CY3C treatment at the late growth stage. The CY3C treatment significantly enhanced the yield, quality, and active components of P. ternata compared to those for CC treatment. The CYGYGC treatment achieved the highest tuber yield, showing 438.99% increase over CC and 5.26% improvement compared to CY3C. While CYGYGC provided similar quality improvements to CY3C, it also resulted in significantly higher active ingredient contents. Furthermore, the phenolic acid content was higher in rhizosphere soil than in root surface soil, demonstrating the migration of phenolic acids during rotation. Increasing the frequency of green manure considerably reduced soil phenolic acid levels. There was also a significant negative correlation between the yield of P. ternata and the presence of gallic, ferulic, and syringic acids in the rhizosphere soil. Double-cropping green manure after wheat harvest effectively decreased these acids, promoting P. ternata yield and reducing the restoration time for CC. Correlation analysis identified cinnamic acid and protocatechuic acid as critical factors influencing the quality and active components of P. ternata. Overall, incorporating green manure after wheat reduces harmful phenolic acids in rhizosphere soil, thereby shortening the rotation restoration period and providing a sustainable cultivation strategy for P. ternata.