Subject: Re: Legumes

From: Keith Elwell-Gavins <[email-masked]>
Date: Fri, 29 Aug 1997 15:44:40 -0700

Mike Skinner wrote:
> 
> Jack,
>      What kind of legume specifically would you recommend for the Texas panhandle
> where I live? On dryland, particularily. The conflict I see is between water conservation and fertilizer/tilth improvement. This area receives between 15 to 25 inches in various sized events and temperatures usually 10 to 15 below in winter and 100 degrees in the summer. Not to mention the wind of 45 mph. Challenging!
>     Anyones' thoughts and comments would be appreciated.
>         Sincerely,
>            Mike Skinner, [email-masked]
> 

Mike, 
        From my earlier post you can see that I'm also looking at the
use of legumes in PC. My climate here on the central tablelands
of inland New South Wales is also pretty severe with -10 degrees C
winters to 40C summers. Rainfall is about 600 mm (24") but we seem
to be having 3 or 4 years of drought out of every 5 at the moment.

One of the best local legumes I have growing wild is the acacia
species which have the advantages of being:
 
1. quick growing in almost any soil, 
2. perennial, 
3. leguminous, 
4. drought and frost tolerant, 
5. fairly open in habit and therefore does not create too much shade 
for understory spp., 
6. wide variability from small shrubs to trees.
7. profuse flowering with subsequent good drop of pods and seeds,
8. many seeds edible (makes a great coffee substitute!)
9. winter flowering (aesthetically stunning when in flower - a benefit
I think we often ignore in PC in our quest for functionality),
10. seeds will keep for many years.

The only negatives would perhaps be their relatively short life 
(5 - 10 years for the local spp. - some live longer). Their life can be
extended by prunning (and as Jack Rowe pointed out from 40 to 90 
percent or so of nitrogen ends up in the leaves, so this is a good way
to return nutrients every year). Also the seeds need to be activate
before planting by soaking or scarifying, but this is easy and the
germination rate is high. 

Most acacias are shrubs in the 2-3 metre range and will grow in the 
most hostile soils. They are usually fairly open and so allow 
understory plants without difficulty. (I am researching the use of
ground-cover acacias which the local nursery industry have developed
as well as tracking down any natural cultivars - as a ground cover I
think they will be excellent in PC). Our local species are pioneers and
seed naturally in the most degraded and disturbed spots. They like
growing underneath open eucalypts, but this is not symbiotic and are
quite happy on their own even in fairly dense concentrations (there is 
a local acacia farm forestry trial taking place by the government 
research body (CSIRO) - I am attending a progress seminar on this at 
the end of September - I'll post a report).

So, I guess you can see that I like acacias. As a PC plant they are
among the best, but even in Australia they have not yet been used to
their maximum benefit. I do not know what species you have available, 
but I think many of our varieties have been exported. If you do have
any Australian spp. available, let me know and I will give you the
horticultural info on them and suitabilty to your site.

All the best, Keith.

 =====================
  Keith Elwell-Gavins
    Queanbeyan, NSW
      Australia
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