Work

Moderate nitrogen fertilization modulates rhizosphere biological functionality to enhance growth and quality of Pseudostellaria heterophylla cultivated under continuous cropping

Year: 2026

Type: article

Abstract: Pseudostellaria heterophylla , a high value medicinal crop in China, often suffers from yield decline and quality decrease under continuous monoculture. While nitrogen (N) fertilization modulates soil biogeochemistry and plant productivity, the dose-dependent effects of N application rates on P. heterophylla performance under continuous cropping conditions remain unclear. We conducted a field experiment to evaluate how gradient N application rates (60, 90, and 120 kg N ha −1 ) affected plant growth indicators, yield, bioactive components, rhizosphere soil chemical properties, enzyme activities, and microbial community dynamics in continuously cropped P. heterophylla. Compared to low-N (60 kg N ha −1 ) and high-N (120 kg N ha −1 ) treatments, moderate N application (90 kg N ha −1 ) significantly enhanced plant growth and root yield while increasing the accumulation of heterophyllin B, a key quality-determining metabolite. This optimal N application rate stimulated urease activity, improved nutrient cycling efficiency, and tended to maintain relatively higher microbial community diversity and functional stability within the rhizosphere. In contrast, the high-N treatment intensified soil acidification, suppressed enzyme activities, exhibited a trend toward microbial community dysbiosis and nutrient imbalances that ultimately constrained biomass accumulation and secondary metabolite synthesis. Conversely, the low-N treatment maintained stable soil pH and the N pool but frequently limited phosphorus and potassium uptake, thereby diminishing plant stress tolerance and yield. Correlation analysis revealed that plant growth and heterophyllin B were tightly coupled with soil pH, nutrient availability, and enzyme activities, with these relationships exhibiting stage-specific dynamics throughout the growing season. These findings demonstrate that moderate N fertilization optimized the trade-off between P. heterophylla productivity and rhizosphere ecological sustainability under this site-specific experiment, providing an promising strategy for environmentally considerate cultivation of P. heterophylla under continuous cropping conditions.

Source: Industrial Crops and Products

DOI: 10.1016/j.indcrop.2026.123605