Impact of drip irrigation on soil quality in agrivoltaic systems: A comparative study in desert regions

Agrivoltaic systems (AVS) offer a promising strategy for drylands by integrating power generation and agriculture, yet their impact on soil quality remains poorly understood. This study examined a 5-year-old photovoltaic (PV) installation in the Kubuqi Desert, cultivating Scutellaria baicalensis Georgi between panels, to compare drip and non-drip irrigation effects on soil quality. Soil physicochemical and biological indicators were analyzed across PV and control plots (bare ground with equivalent preparation). Results showed significantly lower mean soil moisture content (SMC) in PV zones versus controls (drip: reduced by 49.7 %; non-drip: reduced by 56.1 %), with no significant differences between beneath-panel and between-panel zones. PV operations also uniformly decreased soil calcium carbonate, total phosphorus, and available potassium, irrespective of irrigation or panel zone. Pearson correlations indicated total phosphorus and available potassium levels were associated with SMC, suggesting SMC dynamics influence mineral weathering and leaching. Conversely, drip irrigation elevated enzyme activities linked to carbon, nitrogen, and phosphorus cycling in between-panel zones (compared to beneath-panel), alongside increases in available phosphorus and nitrogen, both correlating with soil organic carbon. Mantel tests linked enzyme activity to nutrient dynamics, indicating irrigation stimulates biogeochemical cycling. Although the soil quality index (SQI) showed no irrigation differences, between-panel SQI exceeded beneath-panel values, highlighting crop-induced heterogeneity as a driver of ecological regulation. Thus, drip-irrigated AVS can reconfigure soil nutrient cycling pathways in drylands, with ecologically enhanced between-panel zones offering a sustainable technical paradigm for desert ecosystems.