permaculture

[Lawrence London <lfljvenaura@gmail.com>]

Balkan Ecology Project : Nitrogen Fixing Species for Agroforestry Systems
https://balkanecologyproject.blogspot.com/2014/07/nitrogen-fixing-species-for.html
Tuesday, 1 July 2014
Nitrogen Fixing Species for Agroforestry Systems
I am currently working on a Regenerative Landscape Design
<http://www.balkep.org/regenerative-landscape-design-course-aug-31st---sep-13th.html>
for a site in Todorovo, Bulgaria. The plan is to establish an Agroforestry
system known as Alley Cropping wherein rows of mixed species edible trees
and shrubs are planted at intervals with spaces for herbs, forage and/or
grain crops to be grown in between. It's a dynamic system which is
inherently diverse, providing multiple yields and excellent habitat for
wildlife while at the same time being relatively resilient to a changing
climate.

<https://3.bp.blogspot.com/-czVkXFRO6Xo/VpObHK1m_II/AAAAAAAAIKg/ALpJkLx_XVE/s1600/F.jpg>
The site design - Paul Alfrey
An essential component of the design will be the Nitrogen fixing perennial
plants
<http://balkanecologyproject.blogspot.co.uk/2014/05/nitrogen-fixing-plants.html>
within the community of fruit and nut trees. These plants will be pruned at
regular intervals to provide biomass for surface mulch and to release a
biological source of nitrogen to the surrounding productive plants and soil
life by means of root shed associated with top pruning.

When selecting plants for the Nitrogen Fixing component of this design, I
was looking for species that could withstand record lows of -28 (Zone 5),
tolerate some shade, were fast growing, tolerant of trimming and coppicing,
able to grow in clay soils, known to provide significant quantities of
nitrogen, easy to propagate from seed and provide some food for humans and
other animals. The following plants fit the criteria.

   - *Elaeagnus angustfolia* - Oleaster, Russian Olive
   - *Elaeagnus commutata* - Silverberry, Wolfberry
   - *Elaeagnus umbellata* - Autumn Olive. Autumn Elaeagnus
   - *Caragana arborescens* - Siberian Pea Tree

 We are planning to grow the nitrogen fixing plants for this site from seed
and to involve the local community in doing so.  Many local people,
particularly the older generation are skilled horticulturalists with many
seasons of experience behind them. We hope to include a number of these
people in the process of propagation, each one functioning as a individual
unit.  This will keep the propagation process small scale, making it far
easier to use biological methods. The propagation will begin in the autumn
as *Elaeagnus spp*. all require cold stratification unless they are sown
immediately after they are picked. *Caragana aborescens * will be sown in
the spring 2015.