Restoration Agriculture Systems for San Diego County

Farming is never without its challenges, especially in San Diego County. Compared to other farming areas nationwide, San Diego farmers face costly imported water ($600/acre ft.), biologically and nutrient depleted soils, expensive land, and difficult terrain. These pressures force San Diego farmers to be selective in the crops they plant or animals they raise.

Low rain fall coupled with record temperatures can spell disaster for California agriculture unless systemic changes take place.

On the upside, our Mediterranean climate affords farmers the ability to grow exotic and sub-tropical species that can command a high price (until the market is saturated). However, that same Mediterranean climate also means a prolonged dry season with 80% of the year's water usually arriving between December and March. Our coasts receive the least amount of rainfall, on average, with 9.9" compared to the inland mountains' 40"; both paltry numbers for one of the United State's largest agricultural production zones. Wells are used, but they are steadily lowering requiring deeper wells. Salt levels are rising due to the concentration factor from less water, making them either unusable or extremely expensive to desalinate. Aggravating the tight space farmers find themselves in, our region has seenbelow average rainfall and above average temperatures, dry spells lasting 200 years or more, and we import 80% of our water from the Colorado River and Northern California.

Indigenous slaves work fertile land—largely due to their diligent stewardship and restraint—for their Spanish captors.

Historically, California was once Eden in the flesh (as was all of Earth before mankind started treating her as a "free" resource to be plundered and trashed). The first occupiers imported Catholicism, livestock, and exotic species. The Spanish Missions used indigenous slave labor to manage their vast ranchos where livestock freely ranged the vast countryside, consuming anything and everything. Native fauna, and people, were pushed aside as the ranchos landholdings expanded and the originally rich and diverse ecosystems became the dry, brittle, and poorly managed landscapes we know today. Today, in East County San Diego, cows are still free ranged over large tracts of land. After consuming the green flush from our sparse winter rains, livestock are supplemented over our long dry season with imported alfalfa or grains from Imperial County (and beyond) where water is cheaper. Animals continue to graze during this sensitive period, and consume every last edible plant until only weeds and dry, brittle dirt is left. Is there a method of farming our landscapes that exists, or has existed, that can reduce operational costs, diminish purchased inputs, restore the soil, and produce multiple yields? Yes. We believe that climate appropriate Restoration Agriculture systems can achieve all of the above and then some. By blending existing agricultural models appropriate to our Mediterranean climate with the tools in a Restoration Agriculture tool chest, we can create new methods of land management that return marketable yields, restore our ecology, and comply with CA State Legislation's 2020 mandate that local water supplies meet 40% of our region's water demands.

Rotational Animal Grazing

Montados have existed for thousands of years in Portugal and Spain run by local farmers and pastoralists. The Montado is essentially an Oak Savanna landscape that produces a plethora of products from pork and cork, to grass fed cheese and timber. The Montado or Dehesa landscape is very similar to a lot of our pastoral landscapes here in San Diego County.

Montado, or dehesa, landscape of Portugal and Spain (photo credit)

Approximately 10,000 years ago, giant sloths and wooly mammoths roamed the Southern California landscape. Herbivores and Megafauna were crucial to the health of our ecosystems, and similar to the pigs, sheeps, goats, and cows that are crucial to the Oak Savanna ecosystems of the Montados and Dehesas. In their natural state, herbivores bunch together to protect themselves against predators like wolves and lions (we still have a few (mountain)lions in CA). While bunched together, these animals would be pressured to eat grasses that they normally would not eat or face starvation. After the grasses were grazed down to a certain height, or predators were spotted, the herd would move on to greener pastures. This constantly moving prey-predator pattern was crucial for the health of the ecosystem, especially in brittle environments. Grasses were allowed a chance to rest and resprout, stampeding hooves created a protective mulch layer of grasses and pioneer species, and fertilizer was deposited in the form of manure and urine. All of these things allowed the most crucial component in the system, soil, a chance to avoid depletion of groundcover, mulch, and food for the hungry and important soil biology. Most modern day free roaming or free grazing practices no longer incorporate the same type of predator pressures so animals cherry pick their favorite grasses, leaving the less favorable ones to flourish. Soil becomes unevenly fertilized and forage is unable to provide sufficient groundcover to protect the delicate soil. Without the soil-shading groundcover, the land dessicates faster during the long and hot dry season compromising the soil's biology and ability to retain moisture. By rotating animals following a schedule designed with your biome requirements in mind, farmers are able to recreate the traditional predator-prey dynamic. Impact on the land is reduced as recovery times are alloted, fertilizer is left where it's needed, and moisture and soil health are retained.

An example Leader-Follower system that can work with Rotational Grazing practices. (Source: Restoration Agriculture by Mark Shepard)

Grazing effectiveness can be further enhanced with appropriate Leader-Follower systems. Different species of animal are lead through pasture in a pre-determined order based on their nutrient needs, how they consume or forage pasture, and their role in breaking pest and disease cycles. An example system would start with cattle first. Pigs follow next because in addition to being omnivores, they'll actually eat cow dung and help spread it as fertilizer. Turkey hunt insect pests, and also help grind rock that remineralizes the landscape. Sheep would follow next, with chicken, geese, and finally goats finishing off the cycle. Stocking rates, types of animals used, and duration of grazing are all important nuances specific to your biome. What works in one place will most likely work poorly in another. Proper planning and management is essential.

Tree crops laid out on keyline contour with rotationally grazing cattle at New Forest Farm.

Incorporating Trees

Taking this system to the next level, we'd stack multiple functions into these landscapes and mimic the woody perennial crops that naturally occurred in these Oak Savanna landscapes. These woody crops would include staple foods like the acorn, chestnut, hazelnut, olive, and date. By adding these tree and shrub layers into our landscapes, we can protect our soils, create habitat, and produce yields.

"Shade was noted to be nearly as effective as water placement or supplemental feeding location to promote uniform grazing within a pasture." Hardwood silvopasture management, Center for Agroforestry, University of Missouri

The shade of these trees and shrubs adds many ecological and economic benefits to farming systems. For example, the shade of these woody perennials enhances the growth of grasses by reducing evapotranspiration. Studies from the University of Columbia Center for Agroforestry show that most grasses thrive in 40-60% dappled shade environment. These grasses offer more nutrients and biomass to the various animals that are rotated through the system because they are not oversaturated with UV light. Trees and shrubs also provide shade for animals during the hottest parts of the day which leads to less stress, improved weight gain, and better tasting meat.

Keyline Design for Water Management

Keyline design on Mark's New Forest Farm. Crops and livestock appropriate to our Mediterranean climate would benefit from these systems.

Water management is the last and arguably most important piece of any agricultural system. Water always follows the path of least resistance and seeks lower ground. If we can capture and store water at the highest point in the landscape, we can rely on gravity to help us irrigate lower land. A proven technique for effective land hydration exists: keyline design. This whole farm planning system was created by the late great Australian, P.A. Yeomans, who devised a strategy for pulling water from valleys out to ridges to better spread water across a landscape. A keyline-designed water management system sets the pattern on which the trees and shrubs should be planted. The water management system allows the farmer to capture as much water as possible through a passive system of earthworks (berms or ditches in the soil spreading water out along contours in the landscape). The keyline pattern also accounts for machinery sizes for use in the alleyways between the woody crops, improved fuel efficiency for the farmer. When water is evenly distributed throughout the landscape and allowed to soak in slowly, instead of concentrating and rushing off the farm, the trees, shrubs, and grasses all benefit. As a result of this extra water, the vegetation can grow faster and better withstand drought and disease.

Restoration Agriculture

When a farmer combines these rotational grazing strategies with the tree and shrub Oak Savanna patterns and includes a keyline water management system, he or she creates a very resilient, productive, profitable landscape. The methodologies and concepts described above are derived from the work of Mark Shepard and Restoration Agriculture Development. Shepard’s book, Restoration Agriculture, published in 2012, is Acres USA’s fastest selling book of all time. He has been farming an Oak Savanna landscape in Southwest Wisconsin for the past 20 years. Through time spent in Alaska working the land, he came to the realization that by mimicking nature in our farming systems, we could still obtain marketable yields of staple food crops without sacrificing ecosystem health and vitality. In Restoration Agriculture systems, we focus on staple food crops: the proteins, carbohydrates, and oils that provide the bulk of nutrition in diets across the globe. Not only do these systems produce a perennial source of staple food crops, but also, fuels, fibers, oils, and medicines. For example, the Hazelnut is a key crop that we focus on in Restoration Agriculture systems in the Midwest, and is a terrific oil crop. It is capable of producing twice the amount of oil than a soybean, which is one of the most widely sown annual crops on the planet. Not only are hazelnuts native to the Midwest, but because they are a shrub and can live for thousands of years, they are exponentially more ecological and sustainable than the annual soybean which requires tillage, fertilizers, chemicals, and contributes soil erosion and water pollution.

Restoration Agriculture is the future of food and agriculture on this planet. These agricultural systems can be refined and specialized for every type of biome. For our Mediterranean climates, such as here in San Diego County, Montados and Dehesas are the future for resilient agricultural ecosystems. The benefits of these savanna style farming systems is tremendous. They provide wildlife habitat, sequester carbon, build soil, recharge the groundwater table, purify runoff, improve soil biodiversity, and provide the healthiest food on the planet.