Challenges: Perspectives of Expert Growers

Grazing Cover Crops in Orchards and Vineyards

Integrated Crop Livestock Systems

Integrated crop livestock systems, or ICLS, involves bringing animals and cropping systems together for the benefits offered by the combination of both. Grazing of cover crops in orchards and vineyards is one form of ICLS that is gaining a foothold in California. Growers who are trying it find that it can reduce equipment passes for managing cover crops, increase nutrient cycling and soil health, and increase diversity of farm enterprises. Various challenges, however, can also limit the effectiveness and widespread use of ICLS in orchards and vineyards. For example, strict food safety policies require removing animals from the fields 90-120 days before harvest for certified organic producers, livestock can damage trees or vines if not managed carefully, and monitoring and managing the system may require increased labor.

Perceived Benefits

Utilizing cover crops for income

Why would people include livestock in their cropping systems? “As we moved to organic, there was so much more vegetation under the orchards. How can we utilize this? As grass farmers, what can we do?” Benina Montes from Burroughs Family Farms in Denair, CA describes how the idea for livestock integration came from wanting to utilize the excess of grass growing between her almond trees. For her, the addition of animals meant not only utilizing the grass, but also gaining a source of additional income by selling the lambs for meat. She uses not one, but three species to graze in her orchard. Benina started with chickens and cows in between the trees, from which she initially learned about managing animals and crops simultaneously. Then, she brought in sheep to do the bulk of the work. The chickens are able to feed between the young trees, while the cows and sheep stay in the older trees to prevent them from damaging the young ones by browsing. The addition of livestock turns what was once merely weeds or cover crops into a new flow of income.

Reducing fuel consumption

Another key motivation for farmers to integrate crop and livestock systems is to reduce fuel consumption by replacing mowing with animal grazing. Martin Bernal Hafner of Alta Orsa Winery in Hopland, CA has long faced the challenge of having to use equipment small enough to fit between the rows of his closely spaced grape trellises. Tractors are too large, so instead each row is hand mowed. For him, the sheep provide an opportunity to replace this hand mowing, and its increasingly costly fuel requirements, with beneficial feed for animals. In his case, Martin contracts grazers instead of owning his own sheep, which means he does not get the benefit of selling lambs or wool and is paying for the grazing service. Also, since his estate is located on a steep incline and is difficult to reach with large vehicles, he said “unfortunately, because of our size, it was really difficult to find someone” to do the grazing. Eventually, Martin was able to find a small sheep enterprise that suited his economic constraints and was able to transport sheep to the property. From there, he “only has positive things to say” about bringing the sheep in, replacing the fossil fuel-based machinery that was used before.

Many farmers find this aspect of livestock integration to be a hugely beneficial factor, including Raquel Krach of Massa Organics in Glenn, CA. “We’ve brought them [sheep] in as weed wackers and mowers”, demonstrating how the sheep are able to replace machinery. And they do a great job at it. “There are times when we walk through after the sheep have been there and it almost looks like they mowed it”, says Benina Montes. Not only the grazing itself, but the trampling of the grass is something that Raquel particularly noticed when introducing sheep to her almond fields. Trampling knocks down tall plants and brings them into contact with the soil and the associated microorganisms, stimulating decomposition (Li et al, 2021). “Some of the vegetation we have had better be trampled than grazed, and by using high stocking density we can accomplish that”, said Dan Macon, of UC Cooperative Extension and Flying Mule Sheep Company, when discussing the impact of sheep on vegetation.

Soil health

Currently available research suggests benefits of ICLS for the soil ecology and climate resilience of cropping systems (de Faccio Cavalho et al., 2010). Livestock integrated systems have a positive impact on soil nutrient availability as the nutrients added through manure are highly available forms for the plants (Garrett et al., 2017a). Farmers recognize this potential in their own fields even without the statistics to prove it: “The magic that they are able to do with all of the nutrient cycling,” is how Benina Montes describes it. The addition of manure to the soil also increases microbial activity, which has positive effects for soil health. Bacteria from the rumen that are expelled from animal manure play a nutrient cycling role in the soil ecosystem (Attwood et al., 2019).

Sheep grazing in an orchard at Burroughs Family Farms. Photo courtesy of Benina Montes.

Carbon sequestration

Another key benefit that has been studied is the impact of grazers on carbon sequestration. Grazing can be considered a climate beneficial practice when properly managed in terms of stocking density and rotations so that the action of grazing increases below ground carbon (de Albuquerque Nunes et al., 2021). This increase can be achieved by a few mechanisms. First, the act of grazing increases the plants’ allocation of energy into growing more root biomass. Grazing can also increase carbon sequestration by increasing root exudates of sugars made with carbon from the atmosphere (Schuman et al., 2002). These exudates feed microbes in the soil, creating a more resilient soil ecosystem by supporting more soil life and diversity. These mechanisms signify the potential for livestock integration to increase soil carbon sequestration (Garrett et al., 2017a). In the future, farmers could benefit from carbon credit markets as ICLS research better informs the functioning of these markets.

Agritourism

Another benefit from ICLS is increasing agritourism and attracting visitors to the farm. Miguel Garcia of Napa RCD noted that “we had a volunteering event, and people really enjoyed looking at the sheep” (Napa RCD et al., 2020). This attraction to sheep, and likely other animals, can spur conversation as to the types of practices being put into place at the farm, or simply attract people to the farm based on curiosity and interest. This attraction extends to marketing as well, as Martin Bernal Hafner pointed out: “people like to see animals on social media. It speaks to the type of farming being done.” Animals add to a more “natural” image that promotes the sustainable and familiar feeling associated with farms. This can make people more interested in visiting the farm or participating in the farm in some way.

Unknown Benefits

A lot of potential benefits of livestock integrated systems have not yet been investigated by academic research, but are accounted for in other contexts. For example, biodynamic farming values the presence of animals and acknowledges the importance of their roles in the whole ecosystem of the farm (Turinek et al., 2009). This “animal energy”, as it is often referred to, could have potential benefits that are scientifically explainable but have not yet been studied.

Challenges

So why doesn’t every orchard and vineyard manager integrate livestock into their systems, or vice versa? Like the implementation of any new farming system, there are some obstacles in achieving successful ICLS. The lack of policy support and scientific research makes ICLS in California somewhat of a new topic, which can instill doubt among farming and policy making communities.

There are still many unknown factors about ICLS, which can make it intimidating in itself because the risks and gains are a mystery to many. For instance, questions like the true economic value of ICLS and the best cover crop mixes to plant for both crop health and animal health are questions farmers have. More research is therefore required in these areas to better understand the functionality of ICLS in practice.

Food safety laws

Food safety laws are some of the greatest obstacles in implementing ICLS. As explained by Benina Montes, “The biggest [challenge]…is the food safety because historically almonds have been harvested off the ground but even right now [in July] I have vegetation the sheep could be eating”, but it was too close to harvest to let them in the orchard. Organic regulations require animals to be removed from the crop field 90 days before harvest if crops are harvested above the ground and 120 days before harvest if crops are harvested on the ground (Garrett, 2017b). Therefore, this drastically cuts into the amount of time the animals can be on the fields doing the work they are intended to be doing. This limits many farmer’s desires to implement ICLS because the animals can’t even be in the field during some of the most critical times for mowing. “It's crazy that they can’t be out there!” says Raquel Krach. Many farmers have strong emotions towards these rules as they believe there is not enough research to support the decision to keep the animals off the land that far in advance. Many researchers and policy makers, however, have concerns for human safety and support the rules to ensure this. Field research is currently underway to investigate the length of the time needed to ensure food safety after grazing. This research could potentially inform alternative policy to better suit the needs of both farmers and consumers.

Crop, soil and equipment damage

Many farmers are concerned with how the animals will interact with their crops when integrating livestock into their existing cropping systems. For example, will animals debark perennials or eat the target crop? However, most farmers have found that the damage is minimal when the stocking density is well managed. Rotating on a high density, frequent movement plan supports the animals in eating only what they are expected to. “As long as we are moving the coop through, the birds do a great job”, said Benina Montes about her chickens in her orchard. This relates not only to chickens, but to other animals like sheep as well. One farmer, Brian Paddock of Capay Hills Orchard in Esparto, CA noticed that the sheep were more likely to browse or debark his almond trees if they were out while it was raining. Martin Bernal Hafner noticed an issue in stocking density by finding bare soil in the area where sheep were grazing. Over stocking could also lead to soil compaction, which is another major concern for farmers. With monitoring and proper time management these issues can be avoided.

The same concern goes for damaging equipment. Drip lines could be damaged by animals walking through and over them. However, there are different ways farmers can deal with this obstacle. Some have opted to raise their drip lines so that sheep avoid touching them altogether. Martin Bernal Hafner, on the other hand, left his drip lines where they were and experienced no problems. “I was surprised by the minimal impact they have on the irrigation because that was probably my biggest concern,” reflected Martin. Evidently, the behavior of the animals can be context specific. Either way, adjusting the height of the lines makes this problem avoidable.

The need for extra management, however, may require more of the farmers’ time. Raquel Krach, for example, moves her sheep daily to ensure that no crop damage occurs. However, increased time in the field also means increased monitoring of the system and potentially better care for the trees or vines. ICLS also eliminates some of the time required for managing equipment and machinery, which should be considered in determining the total labor difference.