Notes on the implementation of a Successional Agroforestry plot

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The notes below are a guideline for the implementation of a successional agroforestry plot. They are, by no means, a ‘how to’ check list. Instead these reflections are our way of connecting with other fellow designers to get some feedback and exchange some ideas. As we get ourselves ready for the implementation of our next plot here in Australia, we will share more about our project.

According to Ernst Göstch (1995) the implementation of successional agroforestry systems must be optimised following some steps so that a positive energetic balance can be guaranteed:

  • First it is necessary to identify the adequate species, the species consortiums and the natural succession of these consortiums with a specific region, soil or similar climate;
  • Second, it is also necessary to identify the most appropriate moment to begin each cycle. In other words, the time of implementation (or management of an already established plot) must be chosen so that each species find the best conditions to establish themselves and thrive;
  • After gathering this information it is necessary to design and plan the implementation as to achieve the maximum possible biodiversity in the system. The design and planning of the system must also fulfil every strata and life-cycle niche to optimise vital process in the whole system (including soil life);
  • Forth, pruning and sacrificing of selected plants is used to speed up the system’s growth and natural succession.
Cross-section of a system implemented with tree rows 5 metres apart and with 3 beds for horticulture/understorey cropping in between. It is possible to see timber trees already pruned as emergents, bananas and other fruit trees as high and medium strata, and shrubs and ground covers as produce. Illustration by Osmany Segall (Fazenda Bella).

The preparation of the successional agroforestry plot

Part of the reasons why successional agroforestry is financially viable for small farmers is that it provides a stratified poly-culture of trees, shrubs and plants with varied life cycles. Consequently the root system in these plots is also multilayered and can nurture the production of produce bringing up minerals and nutrients and water from deeper soils. Such strategy guarantees that the farmer may (if planned in the design) start cropping greens and herbs within 30 to 45 days. These crops may be followed by others within 3 to 6 months, then by annuals. Some fruit trees might start producing within 9 months to 1 and half years.

The design of the rows – Usually the successional agroforestry plots will be developed with 5 to 7 rows or beds with the outer rows receiving a poly-culture of plants and taller trees and the middle rows the short cycle or annual crops. The distance between the outer rows may vary from 5 to 8 metres, depending of the farmer’s goals. If the goal is to work with fruits, value-added products and timber trees as soon as possible, the outer rows will be placed within 5 mestres of each other. If the goal is to have a market garden functioning for longer so as to build an income from produce the outer rows can be placed within 8 metres of each other. While in the former the canopy of the taller trees can start closing within 2.5 to 3 years, the latter will take about 4 to 5 years to close. In both situations, however, the farmer can bring more sunlight into the system by pruning or cutting out trees.

The rows might be laid on the landscape perpendicular to the sun’s arch as to maximise light exposure. If, for whatever reason, rows are placed along the sun’s arch, it is necessary to make sure that the outer row closest to the sun does not shade the others (another situation in which rows might be placed further from each other).

The weeding of the area – Whenever possible, the preparation of the area must undergo a manual weeding with special attention to species that might grow from rhizomes, seeds or cuttings when the plot is being cleared by hand-tools or machines. Other non-desired plants can be cut, preferably chopped in a chipper, and used as mulch to cover the beds. Pay special attention to the possibility of saving cuttings, seeds, bulbs or suckers of desired plants.

The soil amendments – Although it is possible to start recovering a degraded area using the understanding of natural succession, nitrogen fixers and a ‘chop and drop’ system, it is better to neutralise the soil’s PH, mineralise and fertilise it when first establishing the plot. Lime and rock dust can be spread with half of the amount of fertiliser that will be used as the soil is being lightly cultivated and beds are being formed. This makes sure that the soil’s PH and eventual lack of minerals will be corrected in the subsoil. The second half of the organic fertiliser available can be spread and mixed with the topsoil in the beds.

The shape of the beds – The beds are usually about 60 metres long, 30 centimetres high, and 80 centimetres wide. The shape of the beds is convex at the top as to help the water retention. The paths between the rows are usually about 30 centimetres wide and covered with banana (or other tree) trunks cut longitudinally in half and placed across on top the path. This avoids compaction and allows the spreading of mycorrhizal fungi from one row to the next. In the case of using banana trunks, they also have a second function of passive irrigation as they slowly release the water contained in them to the soil.

Cross-section of a bed showing: the convex shape to improve retention of water and nutrients; longitudinally cut trunks put across on paths to prevent compaction and foster the spread of mycorrhizal fungi in the whole plot; and a consortium with lettuce, taro, corn and beans. Illustration by Osmany Segall (Fazenda Bella).

The positioning of the beds in relation to the plot’s hydrology – Usually little attention is given to contour lines in successional agroforestry. Most often rows will be placed with a north-south alignment in order to favour the plants’ access to sunlight even when this implies rows being established down slope. In these cases, what is often explained is that if the area is established properly, the runoff will not be able to cause erosion (notes from courses). First, because both the beds and the paths are covered with mulch and cut trunks. Second, because the system’s multilayered strata and dense planting also prevents the raindrops’ direct impact on the soil. Our experience in the Farm Bella, in Brazil, however was that positioning the beds on contour optimised the use of irrigation water. The beds that were laid on contour (and roughly east-west), had a fast growth and demanded more pruning work to grant sunlight access to the system.

The order of the planting – The planting of seeds and seedlings and mulching must take place immediately after the beds were formed and fertilised as to avoid the growth of undesired species. Large seedlings of trees or banana suckers must be planted first. Smaller cuttings (e.g. cassava), rhizomes (e.g. potatoes, taro, ginger) and seedlings (e.g. lettuce, parsley) second. Finally the seeds of plants that will grow straight in the soil (e.g. radish, carrots, beetroots).

 

List of species with the strata and life-cycle they occupy in the Syntropic System.

Cycles Placenta I Placenta II Secondary I Secondary II Secondary III Climax
Strata (up to 6 months) (up to 2 years) (up to 10 years) (up to 25 years) (up to 80 years) (more than 80s years)
Emergent Corn, Kale, Sorghum Sugar cane Pawpaw, Mulberry, Cecropia Eucalyptus, Balsa Tree, Moringa Angico (Nitrogen fixing shrubs and trees), Brazilian Fern Tree, Peach-palm, Copaifera Açaí palm, Barú (Dipteryx alata)
High Lettuce, Broccoli, Rice, Cabbage Cassava Banana, Lychee, Leucena Moringa, Ingá, Juçara (Euterpe edulis), Cedro (Cedrela fissilis) Mango, Avocado, Java Plum, Ceiba Kapok tree, Rubber tree, Mahoganey
Medium Beans, Tomato, Soy, Carrot Pigeon-pea, Arrow leaf elephant ear, taro Banana, Sweet lime, Star fruit, Pitanga Orange, Lime, Graviola, Cacau Cashew, Neem tree, Yellow Monbin Cupuaçu
Low Beans, Cucumber, West Indian gourd, Pumpkin Pineapple, Tumeric Pineapple, Taro, Ginger Coffee Coffee, Cacau Coffee, Cacau

Note: This list was developed for areas in the tropical climate. Although most of these species could be used in the Northern Rivers of NSW, the subtropical climate, geography and microclimate might demand caution with exotics or species that will simply not thrive in this area and climate.

Note 2: This article was based on the booklet O Renascer da Agricultura. Götsch, E. (1995). Rio de Janeiro: ASPTA; and on notes taken by the Farm Bella team on courses with Ernst Gotsch and Juã Pereira between 2014 and 2016. In addition, this article was based on the experience with the implementation of Syntropic Farming systems at Fazenda Bella, in Brasília, Brazil.

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.