Applying Keyline to Successional Agroforestry

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Despite sharing most of the principles backing all regenerative approaches, successional agroforestry was devised in Brazil strongly influenced by the work of Ersnt Gotsch and is broadly known and practiced as agrofloresta. The development of agrofloresta in Brazil was a labour of love and partnership among agronomists, consultants, campesinos, indigenous people, marooned slaved descendants and lately the MST (the Landless Movement). This practice evolved in Brazil without any influence from other regenerative approaches or design systems.

Although many people have been comparing successional agroforestry (a.k.a Syntropic Farming) with Permaculture, they are different things. Successional Agroforestry is an agro-eco-system that uses natural succession and the forest structure to create food production systems. Permaculture is a holistic design system (dealing with food production, energy, water, waste, housing, and economy). And that is why Permaculture, or any other regenerative design system for this matter, can make use of successional agroforestry methods when it suits the design’s context. In this article I discuss the positioning of tree rows in relation to sun aspect and hydrology in a way that integrates Keyline® farm planning concepts and successional agroforestry.

This picture of Jason Adam Hallman’s property over the Syntropic Farming community page on FB initiated the discussion about on and off contour systems.

Note: On the 3rd and 4th of November we have the course Forestry in Practice with Darren Doherty . The course will focus on the functions of flora, fauna, fungi and forest layout within forestry systems and the aim to equip farmers and primary producers to increase climate and financial resilience of their enterprises through the integration of diversified forestry systems in their properties and enterprises.

Successional agroforestry is not a holistic design system. It is a very efficient approach to food, timber and fibre production in tune with agroecology. Most farmers using successional agroforestry, however, rarely use it in conjunction with sector, zoning and slope analysis; tools more commonly used in Permaculture. It is quite common to find tree rows running down a slope when this coincide with the north-south alignment that favours sunlight exposure. Because such approach does not take hydrology into account, it is something like a sacrilege for those influenced by Permaculture design or The Keyline Scale of Permanence. This is a valid concern, especially in erosion-prone areas or dryer regions. Best practice in successional agroforestry, however, does not leave a tiny bit of soil exposed. Tree rows are established densely with consortiums of plants that fulfil all of the forest strata and life cycles from day one. All beds are covered with mulch and the paths are covered with tree or banana trunks cut longitudinally in half and put across the paths (see foto of Fazenda Bella above). In sum, when a successional agroforestry plot is planted properly, there is no way a rain drop will hit the soil directly. And as the system grows, the rain will splash through the different strata, and by the time it gets to the soil it has lost all its eroding power. The problem is when a system is established in parts or not to standard and a heavy rain event comes. In these circumstances erosion might happen; and at a fast rate.

In general, the successional agroforestry’s rationale is that sunlight needs to be prioritised over hydrology and slope angle. Successional agroforestry plots established all over Brazil have very little connection with a holistic farm planning. The only project I am aware of in Brazil that implemented successional agroforestry areas on contour lines and in a large scale is at Fazenda da Toca. However, I do not know who devised the planting plan. Because successional agroforestry systems are indeed efficient and have, overall a hugely positive impact in the properties they are established, often the lack of connection between other elements of the property or of a whole farm planning, seem to be forgiven. The fact is that people tend to be dogmatic about approaches that work well. They also tend to make qualitative comparisons that are most often out of context.

Part of Fazenda da Toca in Brazil using successional agroforestry methods with tree rows on contour.

Planning the establishment of our next Syntropic Farming plot here in Australia we encountered a challenge. Our approximately 5,500m2  plot lies on a south facing slope, surrounded by gravel roads and prone to erosion. Exactly due to these erosion risks, local Council would not approve the establishment of tree rows on a north-south alignment; often recommended by the successional agroforestry tenets. For most people used to work with successional agroforestry a system running on contour (roughly East to West in our case) might be too shady. The conundrum for people in this situation is: should one optimise sunlight and run the risk of erosion? Or should one prevent erosion at the expense of production (which is sunlight-related)? But this is not really a conundrum for us as we did not have the option of establishing a north-south aligned system.

We were left to consider that rows established on contour might not be able to support the rain events that are common in our coastal region in northern NSW, Australia. Some farms with contour trenches had their rows affected by erosion during the storm brought by Cyclone Debby. But I suspect the damage of a 700mm rain event on a recently established off contour system (specially with rows running down the slope) would be much worse.

 

Before and after pruning of gum trees and bananas at Fazenda Bella, Brazil.

At Fazenda Bella, my family’s farm in Brazil, we established the first plot on contour, but have now established other plots for comparison. It is still too early to know for sure, but the system establish on contour seems to grow better; probably due to better hydrology. The only hindrance was that the fast growth demanded extra pruning maintenance (as shown in the picture above). After talking with my brother, Osmany Segall, about our experience at Fazenda Bella in Brazil and the challenges we are facing here in Australia, we devised a third option to respond to the challenge. We decided to use David Holmgren’s Permaculture Design Principle 8: “Integrate rather than segregate”. Hydrology-wise, we decided to establish the rows using a Keyline planting pattern. In this approach rows are established starting in the highest possible points in a adjacent valley with a mild fall gradient to the ridge.

 

In terms of sunlight exposure, however, we decided to plant the hight strata trees that anchor our system with a north-south alignment even though our Keyline® rows are roughly aligned east-west. In lining the high strata trees this way, we expect to have corridors of light as the sun moves through the day, while the topography of the beds optimise the hydrology with the use of the Keyline® planting pattern.

I am aware of discussions about successional agroforestry being more productive than other design approaches such as Permaculture or the Keyline Scale of Permanence. These discussions usually come from a non-integrative (and often competitive) perspective. Those strictly focused on food production tend to favour successional agroforestry in their comparisons with Permaculture. There also those who identify themselves strongly with successional agroforestry saying that they do not want this approach to be appropriated by Permaculture. Others with a strong background in regenerative design approaches tend to argue that all regenerative approaches ever devised fall under the regenerative design umbrella and, therefore, should be appropriated in order to promote faster and more efficient change to our food, fibre and timber producing methods.

Our design solution is not a ‘how to’. As Allan Savory, the founder of Holistic Management, teaches, first define your holistic context, to then discuss your options. In our context, this approach will hopefully allow us to optimise sunlight by creating corridors of trees that are lined north/south, but it will also allow us to improve hydrology and avoid erosion establishing the rows on a Keyline® planting pattern. There are other specificities such as the holistic context of the project, the spacing of trees, which trees are anchoring the system, how wide the system is and how many rows there are, etc. But I will leave these to be discussed and explained in future articles.

Upcoming Agroforestry Courses

Forestry in Practice – With nearly 30 years of experience and literally thousands of farm plans under his belt, Darren J. Doherty comes to the Northern Rivers (NSW, Australia) to teach the course “Forestry in Practice“. The course equips farmers to holistically integrate trees in their landscapes and enterprises. Darren, who also works closely with livestock producers, has been an adamant promoter of tree integration for all farm enterprises. The course will run on the 9th and 10th of February, 2019, at the Holos Regenerative Design learning site in Brunswick Heads, Northern New South Wales.