Tag Archive for: grazing

By Dr. Seeta Sistla, Natural Resources Management and Environmental Sciences DepartmentCal Poly, San Luis Obispo

With the dual growth of utility-scale solar energy and food production, fallowed agricultural landscapes represent a particularly promising area for the deployment of solar arrays because these systems have the potential to recover with shifts in management practices (Tscharntke et al., 2012;  Wright et al., 2012). California is a national leader of both solar energy development and agricultural production. As water becomes scarcer and costlier, there is growing tension between land-use choices centered around maintaining conventional agricultural systems, transitioning land to renewable energy farming through solar energy development, shifting agricultural strategy (e.g., conventional to conservation farming), or alternate land uses (e.g., housing development).

Placing solar arrays on farmland and other human-modified landscapes represents a promising area to unite energy production with ecological restoration and the sustained conservation of ecologically valuable land. The potential for ecologically improving degraded landscapes with targeted solar array placement will be governed by biogeochemical interactions between abiotic and biotic factors (Figure 1).  Despite the potential ecological and economic synergistic benefits that coupling these land uses could create, the impacts of solar arrays on fallowed farmland and other disturbed landscapes are not well understood.

Figure 1. Microclimatic effects of USSE array on fallowed agricultural landscapes.

To address this deficit, we are studying the direct and indirect effects of utility-scale solar energy in conjunction with sheep grazing on soil and plant characteristics. This work includes collaborating with agricultural stakeholders, undergraduate and graduate students, and solar developers (Figure 2).

Figure 2. Sampling plant and soil conditions at a solar farm on the California Central Coast.

To date, we have found that land in the direct footprint of the array panels hosts a plant community with increased nutrient content and forage quality and maintains a greener plant community for longer periods than the surround area.  These findings likely reflect reduced water stress due to shading in our arid western landscapes, highlighting the potential synergy between carbon-free energy production, rangeland management, and water conservation (Figure 3). Our group continues to investigate these plant and soil responses to array placement at two solar sites on the Central Coast of California and looks forward to opportunities to collaborate with others.

Figure 3. Sheep grazing within one of our solar array study sites. Note the shift in vegetation greenness beyond the array area.

References

Tscharntke, T., Y. Clough, T. C. Wanger, L. Jackson, I. Motzke, I. Perfecto, J. Vandermeer, and A. Whitbread. 2012. Global food security, biodiversity conservation and the future of agricultural intensification. Biological Conservation 151:53–59.

Wright, H. L., I. R. Lake, and P. M. Dolman. 2012. Agriculture-a key element for conservation in the developing world. Conservation Letters 5:11–19.

In this webinar from the Indiana Conservation Cropping System Initiative, AgriSolar Clearinghouse partner Greg Barron-Gafford provides an agrivoltaics primer and a discussion of potential for agrivoltaics in climate-smart crop practices. Byron Kominek then describes his successful agrivoltaic farm, Jack’s Solar Garden. Byron describes ongoing studies, farm economics, community development, and education programs at the farm. Stacie Peterson closes the webinar with a description of the agrivoltaic resources available in the AgriSolar Clearinghouse.

The Montgomery Sheep Farm in North Carolina might be taking mixed use to another level. Not only is it a working sheep farm, it also offers a bed and breakfast for two-legged guests, breeds dogs, and is now using solar to power the entire operation. A WFAE reporter recently visited the farm and reports the farm’s 20-megawatt solar array has not only provided it with additional income related to clean energy, but keeps workers employed and has reduced costs.

One important solar benefit  is a reduction in maintenance costs. The grass under the solar panels no longer needs to be cut, thanks to the sheep who graze under the solar panels on a rotating schedule. This not only reduces costs, but also allows the farm to raise more lambs per acre.

We can have many more lambs per acre than if you put them on a normal pasture because of the solar panels,”  Joel Olsen told WFAE, owner of the Montgomery Sheep Farm.

Olsen says another big benefit is the  shade provided by the solar panels. The shade not only provides cool areas for the sheep during hot summer days, but it helps the grass grow thicker which means more food for  the sheep. This thick grass is much more suitable for the sheep than grass typically grown in an open field, according to Olsen.

The farm currently operates on 200 acres, raising sheep, chickens, and horses. Roughly 400 sheep are rotated on a weekly basis under the solar panels in 30 designated grazing areas.

If you can provide farmers additional income related to clean energy, additional income related to grounds maintenance, you know, it allows our rural areas to remain beautiful and have the people living there to remain employed,” Olsen said.

To learn more about the Montgomery Sheep Farm in North Carolina, listen to WFAE’s story,  here.