Paula Ogilvie

Hallo,

Our community in the garden route (Knysna, South Africa) is battling with infestation of non-indigenous trees (mostly blue gums and wattle). The only solution that local conservation bodies recommend is a toxin called Garlon which you paint on the stump of the tree soon after it has been cut down. Sadly the effect of this toxin is indiscriminate and poisons the soil for years after application. Please could we ask the permaculture community if there is any other 'green' strategy/method for controlling non-indigenous tree growth? The blue gums in the garden route sadly contribute greatly to the fire risk in the area and throttle the growth of the natural (and endangered) plant life which we are trying to establish after the fires ravaged the area in June.

Thanks for any assistance you can offer.

Thanks Bryant - will follow up with them - appreciate it.

Thanks everyone so much for the feedback - I really appreciate it. The water has been tested a friend who lives on the plot next door to the one I'd like to buy - so we're able to confirm the high salinity levels - I'm afraid I cant sensibly account for the high salts originating from the shale. Where bedrock is granite or quartzite elsewhere in the district, people don't have the same problems with salinity. I'll do some more investigating.

Thanks for the suggestion of earthworks Michael - I'm very new to permaculture so only now getting my head around swale construction. The farm is in the Western Cape in South Africa near Knysna. We're fortunate in that the area normally gets substantial rain (700 mm per year), but in the last few the area has been hit by drought. So I thought I'd better plan for some contingencies. I'll do some research on the passive solar option, but as Kevin mentioned, dealing with the brine residue is going to be tough. We thought about draining the brine into an evaporation pond and then selling the salt - it has no nasty metals in it.

Hi Everyone,

Does anyone know of a sustainable, green desalination process for groundwater?

The plot I'm hoping to buy has a borehole, but the bedrock is shale and as a result the groundwater is basically a brine. We could definitely drip irrigate from rain water tanks - but in a drought we may have to use the borehole water and I'm concerned about long-term effect of brine on soil quality. I've discovered a device called the desolenator, which is fantastic (basically a solar-powered still) and worth checking out. But I was wondering if there was a natural mechanism for desalination. I've read that spirulina is amazing at treating brines, but I cant find any detailed information on the efficacy. Can anyone please help me with advice or a contact perhaps?

Thanks