permaculture

[Marsha Hanzi <hanzibra@svn.com.br>]

> > Well I hope this ng attracts a few more people than this. I need some info
> > on permaculture in semi arid areas. Areas with less than 400mm rain per
> > year. What plants grow best in these conditions? I am looking at the
> > wheatbelt of Western Australia where temperatures in summer get to 45c
> > regularly and in winter would drop to about 18c maximums and 0-7c 
> > minimums.
> >

The Instituto de Permacultura em Terras Secas  (Dryland Institute) in Irece, 
Brazil, is
wrorking under exactly these conditions with an "agroforest"model , planting 
opuntia
every meter, strips of native or adapted forrage/legume trees every 2 meters 
( for
forrage and/or mulch) , and  a mix of annual crops in between.  They 
presently have
managed to buy a 15-acre farm and are implanting a demonstration site.
    First results show that the soil tilth has improved considerably, 
increasing
infiltration. As 80% of rain in that region (and probably in other dryland 
areas) is
lost as useless runoff, a system which forces infiltration with mulch plants, 
 and soil
with good structure ( they also used swales) means that they will have access 
to 80%
more water than conventional agriculture does...   The system is young still, 
but at
the end of this planting season ( September), there should be more definite 
results...
    I wrote a brief article on this system in  one of the last International
Permaculture Journals...

Basically for our Australian colleague, I would recommend:  find your native 
plants
which  give abundant leafing and resprout well after pruning , Plant them 
densely and
prune them  when the rains will come... Use cacti to give first windbreak  
protection
while establishing the field.  Prune the cacti at the sides, using  the 
material to
cover the soil, but let them grow tall and get woody,  with a "tree" form, so 
that they
can go after the light, even with a densely -planted field... Also include 
large trees,
to  bring up minerals from lower strata, every 10 meters...They can be  
productive
fruit or wood trees..
    I have no  confirmation on this, but suspect that cacti  mobilize the 
soil elements
in much the same way that tropical palmtrees do.

Finally, or  rather FIRSTLY -   the first principle of Permaculture -  
Observe the
local ecocsystem ( if there still is one...)
Sincerely yours,
Marsha Hanzi,
Instituto  de Permacultura da Bahia
Brazil