[permaculture] mediterranean orchards, terracing and fire protection

Dieter Brand diebrand at yahoo.com
Wed Dec 12 04:48:54 EST 2007


Hi Nora, 
   
  I'm pretty much in the same situation as your are. We bought an overgrown 
  hillside property in the South of Portugal 10 years ago. There are some olives, 
  but it's mostly madrone and cork oaks, both are very typical of a Mediterranean 
  landscape. They get by without water during the summer and usually recover 
  after a wildfire. Seems you got all the heat and fires this year that we normally 
  get here in Portugal. In the last 10 years we burned down once, a neighbour 
  burned down twice in the same time. Even if we are not directly affected, 
  we usually have to evacuate once or twice in most summers when the fires 
  get too close for comfort. The heat and fires are nothing new, they always 
  existed, what is different now is that many small farmers have given up their 
  land which becomes a tangled and impenetrable mass of combustible material 
  5 to 15 meters tall. During the summer heat and drought, a single spark, 
  for example one stone hitting another, can set it all ablaze. There is no 
  way around it, one needs to thin out the undergrowth. 
   
  You don't have to go so far as to practice a bare earth policy though. As you 
  already noticed, it is part of Mediterranean culture (the same applies to the 
  North of Africa) to rid the soil of all vegetation. This has a disastrous effect 
  on soil humus. I have been experimenting with no-till and natural farming for 
  a number of years. I'm still not sure that I will be able to come up with method 
  that would allow this to be commercially practiced in a semi-arid climate 
  like the Mediterranean. Anyway, I don't plough and keep the soil covered at 
  all times with vegetation or mulch. Usually, I cut all the grass in the April- 
  May period at the onset of the dry season. I leave some to cover the soil 
  and use some as mulch in the garden or to make compost. It is best to 
  keep the grass to 4 inches or less during the summer. Mostly, a fire will 
  just burn through without doing much damage if there isn't much combustible 
  material. I also cut the lower branches of the trees and shred them for 
  mulching in the garden. If there is a space of 3 to 5 meters between 
  a low grass sod and the lowest branches, a fire will usually not do much 
  damage. If, on the other hand, your grass grows into low growing branches 
  of trees or if you have a solid mass of bushes, scrubs and brambles, 
  a wildfire can have devastating consequences. 
   
  Around the house, I remove more vegetation and leave less mulch than 
  in places further away. Instead, I use stones and gravel to cover and 
  protect the soil. 
   
  I use the existing terraces, but don't make new terraces or swales. 
  Due to ploughing by previous owners, most of the topsoil has washed 
  away, leaving mostly clay and rubble. Any soil disturbance, like ploughing, 
  making terraces or swales, will turn the little topsoil there is underground 
  and bring clay from the subsoil to the surface that will quickly dry 
  out and crack in the summer. The best way of water conservation is 
  to improve the soil by practicing no- or minimal soil disturbance and 
  by adding all the organic matter to the soil that you can get. A good 
  soil can retain some humidity for 3 to 4 months without rain even in 
  the scorching summer heat. I cut down on irrigation by 80 % since 
  I switched to no-till and mulching. 
   
  "Green mulch" does not help against fires. Even supposing you have 
  enough water to keep your land green during the summer, an advancing 
  fire front will wilt and burn any green plant within a second, thus turning 
  it into combustible material. The only way, as I said above, is to keep 
  combustible material to a level at which a fire will burn through without 
  doing much damage. 
   
  There can be a number of reasons for ploughing under olive tress (for example 
  controlling the larvae of the olive fruit fly), but, unless you see your soil as a
  production machine fuelled by synthetic fertilizers, competition in orchards is
  not an issue. The soil needs vegetation to maintain and increase its fertility.
  The leaves from the olive trees are not enough. I have grass and weeds grow 
  under my olive trees. 
   
  Brambles are very useful. They are an indicator for good soil. I usually 
  broadcast small grains and cover crops into the bramble and scrub land 
  when we get the first autumn rains. Then, I cut/shred the brambles and
  shrubs so as to form a mulch layer covering the seeds. If there is enough
  humidity, the crops will grow through the mulch in a week or two, ready
  to be harvested the following spring or summer. The mulch can burn of
  course, but the fire fuelled by an inch of compact mulch is nothing in 
  comparison to the fire that would have occurred with the 6 to 12 feet of 
  brambles and scrubs before cutting and shredding.  The mulch will
  disintegrate after a while to form topsoil, thus again reducing the fire
  hazard.
   
  There is plenty more to say, but I have got to run now. 
   
  Dieter Brand 
  Portugal


be peace <seed4peace at yahoo.com> wrote:  Dear friends,
my name is nora and i live on a farm and a learning centre called axladitsa avatakia in northern greeece on the peninsula of Pelion (www.axladitsa.org). This is typical mediterranean climate with olive orchards all over the place and some degraded left over mediterranean type of forest and lot of maquis around. We have a land of 24 acres and a big part of it is a bit neglected olive orchard and some overgrown areas that according to local knowledge have been orchard and gardens before. we have just moved into the place last year and are slowly starting renewing the place. there is few dilemmas that we face:

1. how to keep clear the ground in between the olives - so far we were turning around the soil with a tractor - shallow ploughing, but i want to find a different method which would be gentler to the soil. the local knowledge holds the olive for a very "jealous tree" that wont like other things growing around it, hence the ploughing practice. i know about mulching but the area is too large and mulch presents a fire hazard which is very critical in this area. i have considered green mulches but then we would need something strong enough to supress the omnipresent brambles and somthing which gets harvested before the main fire season starts (june). Any ideas? It would be also great if we could get a plant which is somehow compatible and will benefit the olive and mitigates protection of topsoil for which olive is a total disaster having no surface root system.


2. great part of the land is on a steep slope, the local practice is to terrace it, i understand that the terraces have similar function as swales in water retention - is that right? what would be benefit of swales over the terraces? (or vice versa?) what is the maximum slope u can do swales on without causing more erosion?

3. mulching - im very fond of mulching but here the locals are very distrustful of the practice as they consider it a great fire hazard. in long term - with retaining more water in the soil and cultivating the humus layer - does the fire risk become less? can the fire risk be minimalised somehow in the mean time? lets say with the drip irrigation under the mulch? any experiences to share?

4. any fire protection/management advice or resources are welcome!!! so far the two main approaches that i encountered are - clearing the land periodically nevermind the soil. or burn the land - as previously "natural fires" did. im conflicted about both approaches and i feel i need more perspectives, more points of view to gain my own understanding

5. any greek pc contacts, please? or mediterranean? any resources relevant to olive farming and mediterranean?

i hope to get some advice and im willing to continue sharing experience as we learn adn experiment here. I would love to get in touch with other people who have experience with olive farming and mediterranean ecosystems in general. Thanx for considering my message!
peace&pace
norak



'Modesty is dangerous: If we believe we are here to do something, if in fact we have the daunting task of turning around a system which appears destined not only to degrade, demoralize and dehumanize us, but to destroy the ecosystem in the process - we don't have time for outdated social customs. You need to tell me what you can do, what you are good at, how you can contribute to helping to make these changes. And i in turn need to tell you the same. Anything less endangers us. Anything less leaves one of us wondering why the other is not being clear, 'Are you unaware of your gifts? Are you unsure of them ? Am i wrong in estimating your ability?' Paxus Calta





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