Andy Wyenandt

Second year of specialty crops research in full swing at RAREC

By Andy Wyenandt and Dan Ward • September 8, 2025

Figure 1. An image of a few of the silician eggplants being grown in the specialty crops agrivoltaics study at RAREC in 2025.

The second year of the specialty crops research at RAREC is moving along! Like last year, fresh-market tomato, silician eggplant, and bell peppers are being grown under no panel (control), single agrivoltaic (AV) panels, and double AV panels in southern New Jersey. This year, specialty crop transplanting was done on 11 June 2025 and to date there has been 9 sicilian eggplant ‘Palermo’, 4 bell pepper ‘Turnpike’, and 2 fresh-market tomato ‘Red Deuce’ harvests with all harvested crops being donated directly to local food banks and churches in southern New Jersey with help the Master Gardener Program of Cumberland County, New Jersey.

Figure 2. An image of the specialty crops being grown in the single agrivoltaic panel block at RAREC in the summer of 2025.

Harvesting will continue over the next 5 or 6 weeks with data to be shared at upcoming Extension meetings this winter! Along with the specialty crops research, soybeans have also been planted in two of the agrivoltaics research blocks at RAREC this year!

Figure 3. An image of the soybeans being grown in one of the double panel agrivoltaic blocks at RAREC in 2025.

On September 21, 2025 there will be an event at RAREC near Bridgeton and at the Animal Farm on the campus of Rutgers University celebrating Sun Day! Both events are FREE and will run from 10 AM until noon! Registration is required. For more information on Sun Day please click here.

2024 Agrivoltaics Soybean Harvest at RAREC in Southern New Jersey

By Andy Wyenandt and Dan Ward • July 9, 2025

Figure 1. An image of the soybean trial near mid morning at RAREC in 2024. Note: the double AV panel block (closest) with the single AV block (in the background), followed by the control block (no panel) are facing east toward the sun.

In addition to the specialty crops research, members of the RAPS Team are also studied the effects of Agrivoltaic systems on soybean production at RAREC in southern New Jersey in 2024. On Oct 6, 2023, a rye (variety not stated) cover crop was established at 2 bu./A and terminated on 29 April 2024 with Round-up at 1 qt/A. On June 9, pre-plant fertilizer (14-4-14) at 60 lbs/N per acre was broadcasted and soil was worked prior to soybean seeding. On 11 June, soybeans (AG42XF1, ASGROW) were seeded at a rate of 160,000 seed/A in each of two AV blocks each containing a double panel AV system, single panel AV system, and no panels (the same AV layout as the specialty crop study). On June 12, a pre-emergent herbicide application of Lorox at 1.0 lb/A + Dual Magnum at 1.0 pt/A was applied.

Each block consists of a double panel array, single panel array , and no panel system. Each whole plot contains three rows of AV panels spaced 34 ft apart that are 74 ft long (4,736 total sq. ft). The distance (space) between each whole plot are 34 ft which act as a break. The total area of each block is 272 ft long by 74 ft wide (20,128 sq ft or 0.462 A) (Figure 2).

Figure 2. Layout of the agrivoltaics research field site at the Rutgers Agricultural Research and Extension Center (RAREC) in southern New Jersey. Note: the block in the center and to the left above were used for soybean production in 2024. The block to the right was planted in specialty crops in 2024.

Supplemental overhead irrigation was applied regularly to all soybean plots during the production season. As a note, southern New Jersey had one of the driest late summer, early fall periods on record in 2024. On 7 November, all soybeans were harvested by harvesting (e.g. yield) and collecting subsamples (e.g., protein, oil and moisture content) from three different locations in each sub-plot based on their proximity to the solar panel (East side of sub-plot, center of sub-plot, and west side of subplot (Figures 4 and 5) to determine yield, percent moisture, and protein + oil.

Figure 3. An image facing North of the double panel AV block at the Rutgers Agricultural Research and Extension Center (RAREC) in 2024. Note: the solar panel arrays are facing west in the mid-afternoon in this image

A pass of the small research combine with a 5 ft head was used to harvest a 65 ft long section on the east, center of, and west side of each sub-plot (Figures 4 and 5).

Figure 4. An image of soybeans being harvested in the double AV panel block where harvesting was done on the east side (left) in the early morning, the center of (mid day), and west side of each sub-plot (not harvested yet) (right).

Figure 5. Soybeans on the west side of each sub-plot were harvested in the late afternoon as the AV panels were facing west.

Significant differences (P = 0.0114) in yield (ton/A) were observed among the three array treatment types (Figure 6). Soybeans growing under the single or double AV panels produced significantly higher yields (ton/acre) compared to the control (no panel) (Figure 6). There was no significant differences in yield between the single and double AV panels (Figure 6). Analysis of the effects of East-West position and distance from the center point between the array panels row detected no significant main effects, nor interactions, in the first year of this study.

Figure 6. Yield of soybeans grown in the control (no panel), single panel AV, or double panel AV system at RAREC in southern New Jersey in 2024.

Protein plus oil content were not significantly different among treatments or for any of the interactions tested in the first year of this study (Figure 7).

Figure 7. Perecent protein + oil of soybeans grown in the control (no panel), double panel AV, or single panel AV system at RAREC in southern New Jersey in 2024.

Soybean moisture content was not significantly different among treatments or any of the interactions tested (Figure 8). On average, the soil moisture content in the control (no panel), single AV, and double AV panel sub-plots was approximately 13% in the first year of this study (Figure 8).

Figure 8. Percent moisture of soybeans grown in the control (no panel), double panel AV, or single panel AV system at RAREC in southern New Jersey in 2024.

The results presented above of the first year of soybean agrivoltaics research at RAREC are preliminary and should not be used to draw any definitive conclusions about the effects of agrivolatiac panels on soybean production, much more research needs to be done.

Data from the first year of specialty crops agrivoltiacs research at RAREC in 2024

By Andy Wyenandt and Dan Ward • July 2, 2025

In 2024, the first year of agrivoltaics (AV) specialty crops research was completed at RAREC near Bridgeton, New Jersey where fresh-market tomato ‘Red Deuce’, bell pepper ‘Turnpike’, and sicilian eggplant ‘Palermo’ were grown using standard production practices in either a no panel (control), single-panel, or double panel AV system. A timeline for the AV research done at RAREC during the 2024 production season can be found below by clicking on the links.

Bed formation and plastic mulch laying at RAREC in 2024

Transplanting specialty crops at RAREC in 2024

Staking and tying specialty crops at RAREC in 2024. First tie and second tie

Harvesting the specialty crops at RAREC in 2024. First harvest, mid-season harvest, and final harvest

Breaking down the specialty crop trial in 2024.

Figure 1. Plot plan and randomization of sicilian eggplant ‘Palermo’ (e), bell pepper ‘Turnpike’ (p), and fresh-market tomato ‘Red Deuce’ (t) at RAREC in southern New Jersey in 2024. Double panel AV (left), no panel (control) (center), and single panel whole block (right)

Experimental Design. The experiment’s error-control structure was a split-split-split-plot design, with the whole-plot factor arranged in randomized complete blocks (Figure 1). This blocking was implemented to mitigate the influence of field geographic variability, a recognized nuisance factor. In the 2024 growing season, the vegetable experiment was confined to a single block of the randomized complete block design. Future iterations of this experiment are planned to achieve replication at the block level. The initial year’s experimentation focused on within-block treatment effects.

The treatment structure comprised a 3 × 2 × 5 × 3 factorial arrangement of the factors: array type, East-West side, proximity to the central row, and crop species, respectively. The whole-plot factor, array type, had three levels: 1) control (no photovoltaic panels), 2) single panels in portrait orientation (ground coverage ratio [GCR] of 0.202), and 3) double panels in portrait orientation (GCR of 0.404)(Figure 1). All arrays were single-axis trackers with North-South row orientation and a pivot height of 2.44m (8 ft) above ground level. Each whole-plot experimental unit contained three rows of the same array type (or equivalent imaginary rows for the control). The split-plot factor was the cardinal direction relative to the central array row (East or West) within the whole-plot experimental unit. Proximity to the central array row constituted the split-split-plot factor. Within each split-plot experimental unit, five raised beds were established, oriented North-South and spaced 1.52 m (5 ft) on center, to investigate the effect of proximity. The split-split-split-plot factor was crop species, with levels: 1) eggplant (Solanum melongena cv. ‘Palermo’), 2) fresh-market tomato (Solanum lycopersicum cv. ‘Red Deuce’), and 3) bell pepper (Capsicum annuum cv. ‘Turnpike’) (Figure 1). Within each raised bed, crop species were randomly allocated to 4.6 m (15 ft) long sections. Figure 1 shows a detail of the design. To ensure isolation, each split-split-split-plot experimental unit was buffered by three guard plants at each end.

Crop Management. On May 20 2024, soil was prepared by broadcasting and incorporating 85 lb/A of 14-4-14 prior to bed formation. On June 5, raised beds were formed and Devrinol herbicide applied for weed control. On June 6, white-on-black plastic mulch was laid on 5 ft centers in each whole plot for a total of 10 beds. Seedlings were transplanted in single rows with 12” between transplants into beds on June 10 and 11. Standard management practices were performed according to local recommendations, and included staking (June 28), tying (July 3, 16, 22; and August 13) on fresh-market tomato and (July 3, 18; and 13 August) on eggplant, (July 3 and 26) on bell pepper. All whole plots were fertigated either once or twice per week from June 28^th through 11 Oct for a total of 21 times each using 1 lb actual N/acre of NPK (20-20-20). Additional drip irrigation was done as needed. A protectant fungicide + insecticide program was initiated and on July 15, 23, and 29; on August 5, 17, 23; September 5, 20, and 26 pesticides were applied using an air–blast sprayer for the control of important pests and diseases according to local standard recommendations. Additionally, on July 31, a miticide was applied to all plots for the control of broad mites.

Data Collection and Statistical Analysis. Data collection involved multiple hand harvests of commercially mature fruits at intervals of 5 to 10 days, depending on crop, weather conditions, and fruit maturation. Harvest began on August 2, 2024, and ended October 18, 2024, for a total of 13 eggplant, 7 pepper, and 10 tomato harvests. All harvested fruits were weighed and subsequently sorted into marketable and cull categories, with separate weights recorded. Season-long total yields and percent marketable fruit (on a weight/weight basis) were calculated for each sub-sub-sub-plot and used for subsequent statistical analysis. A mixed-effects analysis of variance model was fitted using the GLIMMIX Procedure of the SAS System (ver. 9.4, SAS Institute, Cary, NC 27513). Model adequacy was assessed through conditional studentized residual plots. The model evaluated main effects of cardinal direction, proximity to array, and crop species, along with all their two- and three-way interaction effects. Additionally, two- and three-way interaction effects involving array type with the aforementioned factors were examined. Significant (P<0.05) interaction effects, all of which included proximity, were further investigated by fitting linear and quadratic polynomials across proximities within each level of the interacting model effects. As quadratic terms were statistically significant, quadratic curves were fitted and used for interpretation and presentation.

Effects on Crop Yield. Results indicated a significant three-way interaction effect of Crop type x Array type x Proximity to the center array row on total yield (P=0.0107). All three crops exhibited reduced yields in those beds closest to the array row (Figure 2), where eggplant yield exhibited the greatest reduction, especially in the beds closest to the double-panel rows. There was no significant effect of E-W nor any interaction of E-W with the other effects. There was a clear numerical trend towards lowered yields in the single panel whole plot and even lower yields in the double-panel whole plot for all three crops compared to the control (no AV panels).

Percentage marketable fruit. Results indicated that fruit quality, expressed as the percentage of harvested fruit marketable, was unaffected on tomatoes and peppers, but it was higher closer to the module arrays for eggplant (Figure 3) (Three-way interaction effect of Array type x Crop species x Proximity, P=0.0200). There was no significant effect of E-W nor any interaction of E-W with the other effects.

This study will be repeated in 2025 and 2026 to test the main effect of array type.

Andy Wyenandt

Andy Wyenandt

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