Field-Scale Impacts to Water, Carbon, and Productivity in an Agrivoltaics Array: Initial Results and Data

Agrivoltaic performance and ecosystem impacts are understudied in humid temperate climates, especially across photovoltaic (PV) configurations. To address this gap, we established an agrivoltaic observatory in Wisconsin, USA, comparing an open-sky control with fixed-tilt and single-axis tracking arrays. Continuous radiation, eddy-covariance, soil moisture/temperature, and phenocam observations were paired with vegetation surveys across below-panel, dripline, and alley microhabitats. Clear-sky radiation showed that fixed-tilt panels created persistent below-panel and shaded-side diffuse-dominated light conditions, whereas tracking arrays redistributed shade through the day and increased under-row light. Across May–December 2025, soils in the fixed-tilt were driest at intermediate-to-deep depths, while the tracking maintained the highest deep soil moisture. Within the fixed-tilt, below-panel soils were coolest, yet also among the driest, indicating that throughfall exclusion outweighed reduced evaporative demand as a control on moisture dynamics. Driplines accumulated water at intermediate depths, consistent with rainfall and infiltration concentration along panel edges. Tracking reduced within-array heterogeneity and maintained deeper water storage by uniformly suppressing evapotranspiration through shifting shade. The array showed lower net CO2 uptake and evapotranspiration than control during June--October by 36% and 28%, respectively, alongside higher sensible heat fluxes and lower relative humidity. Flux differences increased after early-August mowing and herbicide application, suggesting vegetation management can rival microclimate in shaping first-year outcomes. Overall, humid-climate agrivoltaic systems form repeatable microhabitat mosaics rather than uniformly cooler or wetter conditions, with array geometry governing light limitation, rainfall redistribution, and vegetative impacts. Our dataset provides a baseline for multi-year evaluation of carbon, water, and productivity tradeoffs.温带湿润气候下的农光互补系统性能与生态系统影响，尤其是不同光伏（PV）配置场景下的相关研究仍较为匮乏。为填补这一研究空白，我们在美国威斯康星州搭建了农光互补观测站，设置露天对照区、固定倾角光伏阵列与单轴跟踪光伏阵列三组处理开展对比研究。本研究针对光伏板下方、光伏板滴水线以及巷道微生境，同步开展连续辐射观测、涡度相关法（eddy-covariance）监测、土壤水分/温度监测以及物候相机（phenocam）观测，并配套完成植被调查工作。 晴空辐射观测结果显示，固定倾角光伏板会在光伏板下方与背阴侧形成持续的以散射光为主的光照环境；而单轴跟踪阵列则会在全天动态重新分配遮阴区域，并提升光伏阵列行间的光照强度。2025年5月至12月期间，固定倾角阵列区域的土壤在中深层范围内最为干旱，而单轴跟踪阵列区域则维持了最高的深层土壤含水率。在固定倾角阵列区域内，光伏板下方的土壤温度最低，但同时也是土壤最为干旱的区域之一，这表明穿透降雨截留对土壤水分动态的调控作用超过了蒸发需求降低带来的影响。光伏板滴水线位置的中间深度土壤出现水分累积现象，这与降雨沿光伏板边缘集中下渗的规律相符。单轴跟踪阵列通过动态调整遮阴区域均匀抑制蒸散发，从而降低了阵列内部的生境异质性，并维持了更高的深层土壤储水量。 2025年6月至10月期间，光伏阵列区域的净CO₂吸收量与蒸散发量分别较露天对照区低36%与28%，同时显热通量更高、相对湿度更低。在8月初开展割草与除草剂施用作业后，各通量的差异进一步扩大，这表明植被管理措施对系统首年运行结果的调控作用可与微气候影响相媲美。 总体而言，温带湿润气候下的农光互补系统会形成可重复的微生境镶嵌格局，而非统一的低温或高湿环境；阵列几何结构决定了光照限制、降雨再分配以及植被影响的特征。本数据集可为碳循环、水循环与生产力权衡关系的多年评估提供基准参照。