Tropical Orchard Establishment Practices and Concepts: Part 1 of 3
As I land back in the rural town of Mastatal, Costa Rica after my yearly rainy season sojourn to the states, I can’t help but step back and marvel at the sheer growth of biomass that has occurred on our farm. Even with the drought-inducing effects of El Niño at play, the ample rain and sun in this humid tropic pre-montane region combined with our strategic planning for soil and water conservation, is a recipe for tremendous growth and regeneration of the landscape. Many of our crop trees have been pulled forth by their apical dominance an additional meter or three. The tubers and rhizomes carefully placed in the soil and mulch a mere six months ago now stand firmly in their place, ignorant of anything that may have occupied that site beforehand.
Working in the humid tropics presents its own unique set of challenges and opportunities, as do all climates. Over the last seven years I’ve been privy to the rapid and somewhat exhausting cycle of life and death on this land working as the farm manager at Rancho Mastatal Sustainability Education Center. The forest here takes no break, there is little brittleness found on these soils even during the depths of the dry season, although climate change may have something to say about that in the years ahead.
Coming from the relatively mild and hospitable farming climate of southwest Ohio, my learning curve in the tropics has been steep. Today though, I am able to stand looking out from my porch on a landscape starting to come into its own. I can see the patterns becoming clearer. Some might call it an agroforest, others a food forest, but usually I just call it our orchard.
Orchard Establishment Strategy
Our orchard establishment implementation strategy and pattern becomes more visible as it is refined year after year. I estimate today, I can get an orchard to production levels in half the time than when we started. Refining the best practices to manage succession has lead to a strategy which is working well for the context of our place and its people. This strategy is the result of much work, experimentation, practice, and knowledge and mentorship of many colleagues, friends, and teachers. Special recognition goes to Chris Shanks and Mitch Haddad of Project Bonafide in Nicaragua, Peter Kring of Finca La Isla in Puerto Viejo, and Jorge Salazar of La Iguana Chocolate here in Mastatal. Over the last decade, these people all worked with the Ranch team to develop and refine the orchard establishment strategy we use today.
This strategy is based on the following concepts and practices. I know it is not unique to our site, nor Costa Rica, but nevertheless we found that it triggers an “ah-ha” moment for students who are building agricultural systems in similar climates. I believe it is worth sharing in some detail and will do so over a three part series. Part 1 below looks at our site goals, layout patterns and approach toward water. Part 2, coming soon, explores our soil management approach.. Finally Part 3 will look at our species selections, as well as select permaculture concepts around guilding, stacking in time and space, and other techniques we employ.
Before addressing the details of this system let’s consider some basic goals of the agricultural/orchard systems on our site. For a review of our project, please see this previous article posted here. Key goals include:
• We understand our capacity: We work with a transient labor pool (our year-long apprenticeship) and do not have the capital to employ a large number of local agricultural workers. Therefore designs that foster familiarity and ease of maintenance out weigh high production goals.
• We value functionality: As an education center first and foremost, we build our site to be didactic. That being said we avoid “demonstration” projects which claim education as an end goal and prefer functional projects which provide productivity as the end and education as a bi-product.
• We trial new and underutilized crops: As a largely foreign entity we have the means to live beyond a subsistence lifestyle. Given this we focus on being the risk-takers and early adopters of practices and species which may or may not succeed.
• We grow for our internal market: We are not located near any major markets and therefore do not actively sell any unprocessed food produced on site (though one of our teammates does sell value-added spices and herbal products). We align our planting goals with our kitchen’s needs, which produces close to 60 meals a day on average or nearly 22,000/year.
• We grow plants that fit our climate and topography: Using the Scale of Permanence we have focused our species selection on plants that thrive in our climate and can be managed most successfully based on our topography. We attempt to mimic the forest ecology that surrounds our property and primarily work with tree crops and perennials. Our site is not easily accessible with tractors and other medium/large scale machinery, therefore we do not design with this degree of access as a criteria. Our tools are primarily shovels and spades, machetes, chainsaws and weed trimmers, and many many hands.
• We love what we do: If the system takes away from our quality of life, causes too much stress, then we change or eliminate that system. This is a labor of love and we need to feel content at the end of every work week.
This article describes the results of many years of trialing different systems. If one were to visit our site (and you should!) you would find various orchards of diverse ages all implemented and laid out differently. What is described here is how we currently design our plant systems and what we most commonly recommend to clients.
Our orchards are laid out in a classic alley cropping pattern. That is, a linear or curvalinear row of perennials with numerous functions, which sandwich the alley of food-producing crops. This pattern on steep slopes is often refereed to as Sloping Agricultural Land Technology or SALT. Typically the land we are renovating and regenerating in this manner is old cattle pasture which has been abandoned and has around fifteen years of pioneer succession or what is called locally tacotal. This is a nearly impenetrable tangle of vines, grasses, and young trees and shrubs. It is very challenging to see the lay of the land through this plant community.
Our first step in establishing any orchard involves clearing the site with machetes and chainsaws. The extensive amount of biomass left over is difficult to work around therefore it is roughly chopped up and arranged as dead barriers on contour. Without this step it would be nearly impossible to do any survey work.
Next, we lay out a series of contour lines with an A-frame. These are spaced anywhere between six and ten meters depending on the goals of the orchards. Generally speaking we space alleys around ten meters on our ridges which causes the spacing in the valleys to approach six meters as the terrain steepens toward the valleys. Most of the tree species we work with have a final mature canopy spacing of six to ten meters as well.
Occasionally we will use a modified (or distorted or inspired depending on your take) form of Keyline patterning. For us this involves starting at a lower contour line and then creating parallel and equidistant lines up slope. One of the many advantages to this layout pattern is that all of your lines are evenly spaced apart, making the spacing between trees easier. Our intense micro-topography can make this layout strategy challenging, but still effective.
On these lines we do the following:
• First a swale is hand dug, approximately 40 cm deep and 50 cm wide as precisely on contour as possible.
• Second a row of leguminous, nitrogen fixing trees (NFT)s/shrubs are densely planted on the lower edge of the newly created berm.
• Next, a row of vetiver grass (Chrysopogon zizanioides) is planted 30 cm down slope of the trees.
• Finally, the original dead barrier material is moved down slope and placed in or just up slope of the swale.
The details of each of these elements is discussed further along. But in essence these are our primary erosion control and nutrient cycling techniques.
Our principal tree crops are either planted in the alley themselves or they are inter-planted with the NFTs, in which case the alleys are designated for herbaceous crops.
This is the basic layout pattern we use. For us, water management with the goal of slowing down overland sheet flow, is key. Because of this goal we are willing to “lose” a few trees as our alleys narrow in exchange for working with true contour (as opposed to parallel equidistant lines). Often as our alleys narrow on steeper portions of the slope, we find these areas become seasonal riparian zones that either a) we want to manage as such or b) provide a unique microclimate for different species. In either case it is unsurprising that water is a major design variable which affects our site in powerful ways.
As discussed above, water management is fundamental to our work at the Ranch. We receive between 4000 and 6000 mm of rain a year on average. Large rain events of over five inches in a few hours occur a dozen times a year and can be back to back to back. A few years ago we received over seven inches on three consecutive days. The erosive force of this water is phenomenal and at a certain point you can only sit back and marvel at the rainforest.
That being said, our efforts to slow, spread, and sink this water into the ground are considerable. Primary techniques we use include:
• Vetiver grass.
• Keeping the ground covered though mulch and good disturbance patterns.
Most readers will be familiar with swales, so I won’t discuss those in depth. We hand-dig swales using picks, spades, and shovels, laid out with an A-Frame. We attempt to make our swales very redundant. They often repeat four or five times down a small slope. Although we believe swales are an important tool in this climate, it is worth mentioning in certain climates, under certain soil types, and dependent on your goals and resources, a swale may be ineffective at best and destructive at worst. Do your due diligence!
Vetiver grass is worth recognizing, as many have done, as one of the most important plants in the tropics. Native to the swamps of India, it is a bunching grass, which reaches nearly one meter in diameter and two meters tall at full size. It is a variety that does not produce seed, therefore it has zero invasive potential. Most importantly, its root system penetrates deeply (up to 6 meters in perfect conditions) and vertically, forming a wall of roots below ground. The vertical growth of the roots minimizes competition with crop trees planted in the alleyways.
We plant root divisions of vetiver at 25 cm spacing on our contour lines. As these plants thicken this hedge becomes nearly impenetrable. It forms a sediment trap above ground and a nutrient trap below ground. The grass is then pruned to 40 cm in height three times/year; and this biomass becomes mulch for nearby crop trees.
This mulch contributes to our goal of keeping the ground covered at all times. The forest floor is rarely exposed, and with nature as our model, we look to do the same. Bare soil combined with rain contributes extensively to both splash and stream erosion. Bare soil is public enemy number one in our climate (and many others). Principle techniques we employ to mitigate this include: mulching and proper timing of disturbance to the native ground covers.
We will discuss mulch more during Part 2 on soils, but first it is essential to understanding our disturbance regime. Again the prodigious growth of all plants here will quickly take over any agricultural crops unless they are cut back (or in conventional farming, herbicide is applied). For us this mostly involves using machetes to chop back the grasses and herbaceous plants which are working to lead succession forward. The timing of this work is key. We want to cut everything back so that the following criteria is met:
• Our orchards are accessible during peak maintenance, planting, harvest, and education (eg PDC) periods.
• The ground cover is cut low enough so that there exists a multi-month period before we need to cut it again.
• The ground cover is cut high enough so that the soil remains covered.
• The ground cover is cut when there is enough rainfall remaining so that growth is strong prior to the dry season.
Detailed observation of plant growth and rainfall patterns informs when and where this disturbance occurs. Our ability to do this well (or poorly) determines how well the soil is covered by living plant material throughout the year. We have found that focusing our energy on doing this well is vastly more important than other techniques such as cover crops, biochar, or planting ground covers. As I’m learning year after year, timing is the most important management variable. We have reduced soil fertility on some of our site by cutting back the ground cover too low and during the harsh dry season. The above criteria is challenging to achieve still today.
Overall we are blessed with an abundance of water. Through earthworks, living plant material, and properly timed ground cover disturbance our orchards benefit from this abundance. When we couple these with an understanding of the nutrient cycling and soil ecology of the tropics we can begin to piece together an effective set of strategies and techniques for our tool box. As we mix in proper species selection and additional establishment techniques the vision for our orchard becomes complete.
Permaculture Design Certification Course
We are hosting our 7th annual Permaculture Design Certification course this April 17th to May 1st 2016. If you are interested in learning more about our site, the methods we use, and our programs, consider joining us!
About Rancho Mastatal
Rancho Mastatal is an education center, working permaculture farm, lodge and community rooted in environmental sustainability, meaningful, place-based livelihoods, and caring relationships.
We offer profound, innovative and authentic apprenticeships, residential workshops and guest experiences. We practice, promote and teach about natural building, fermentation, permaculture design, renewable energy, agroforestry and more.
Our campus encompasses more than 300-acres of picture-perfect waterfalls, crystal-clear rivers, idyllic swimming holes, impressive trees, extraordinary wilderness views, and pristine habitat for the area’s rich flora and fauna. Visitors and participants have access to over 14 km of trails, an extensive library, our working permaculture farm, and the tireless team who make the Ranch such a unique place to learn.
We are located in the rural farming town of Mastatal, situated on the edge of the last remaining virgin rainforest of Costa Rica’s beautiful Puriscal County. It is a wonderful place to take in Costa Rica culture, practice your Spanish, visit other permaculture projects, or catch a pickup game of fútbol.