Measuring Tomato production and Water Productivity in Agrivoltaic Systems

Abstract:

Agrivoltaic systems are dual-use systems which allow for both agricultural and electrical production. These systems also have the potential to reduced water demand and increase overall water productivity of certain agricultural crops. This study observed the microclimate and growth characteristics of Tomato plants grown within three different locations on an Agrivoltaic field and with two different irrigation treatments (full and deficit). Overall water productivity increases could potentially be more pronounced in systems with greater overall water distribution uniformity. The microclimate results showed significant differences in air temperature and relative humidity between all the treatments. Air temperature was highest in the control and row plots (22.3 °C, 21.5 °C) but lower beneath the panels (19.8 °C). In addition, soil temperature and soil moisture content showed significant difference with all the treatments. Increasing shading from panels corresponded with decreasing soil temperature. Average soil temperate was 20 °C in the panel area, 24.7 °C between the rows, and 25.6 °C in the control. When comparing wind speed data from the climate stations, wind speed was highest in control area compared to row area (0.89 m/sec and 0.65 m/sec). Reference ET was significantly different between the two stations in control area and between the rows. Total crop yield was highest in the control full irrigated areas a, b (88.42 kg/row, 68.13 kg/row), and decreased as shading increased, row full irrigated areas a, b had 53.59 kg/row, 32.76 kg/row, panel full irrigated areas a, b had (33.61 kg/row, 21.64 kg/row). However, water applied was also highest in the control (a = 3.15 m³, b =2.94 m³). The combination of solar shading and deficit irrigation has the potential to trade a reduction in yields for reductions in water use. Water productivity was highest in areas which were both shaded and experiencing deficit irrigation, row deficit a (93.11 kg/m³) and panel deficit a (68.90 kg/m³). These results indicate the existence of some optimal water productivity point. These results indicate the potential of Agrivoltaic systems to improve water productivity even for crops which are traditionally considered shade-intolerant.