Re: FW: This is not a weed question
Randall, Rod wrote:
>
> Hi Folks, a friend of mine in Queensland has sent me a doozy of a question
> and while I've suggested maybe a trace element imbalance (either toxicity
> or lack of) or maybe a fungal problem.... I'm not really sure.
> > I received the following enquiry from relatives who live in the Kurrajong
> > district, NSW.
> >
> > "The problem we are having with the soil is as follows:
> >
> > The soil was supplied in bulk as a 'garden mix' some nine months ago, and
> > was used to fill a landscaped garden bed. According to the suppliers, it
> > contained, amongst other things, rice husks and processed sewerage sludge.
> > It also contains a reasonable measure of sand. We planted a number shrubs
> > in the soil including camellias, azaleas, rhododendrons and lavender,
> > along
> > with some herbs and sundry native species. The plants were well-mulched
> > (shredded tree prunings) and well watered. We had good rainfall over
> > spring
> > and summer, and the soil is well drained. After many months, we find that
> > only a few of the plants seem to be doing at all well (lavender), and that
> > most of the other plants look sickly. No new growth is evident from the
> > last
> > good season (while the rest of the garden in native soil has thrived). The
> > camellias and azaleas are yellowing, and some natives are not healthy.
> > Recently our son conducted a school science experiment by planting
> > cauliflower seedlings in a number of soil samples including the garden
> > mix.
> > Those seedlings in normal or supplemented (enriched) normal soil are
> > growing
> > very well after several weeks, attaining some 12-15cm in height. Those in
> > the garden mix have grown little, if at all. They are 4-5cm in height, are
> > discoloured and distorted. The addition of fertiliser to one of the
> > samples
> > has made no difference. We are very concerned that the garden mix is
> > either
> > toxic, or deficient in vital nutrients. The suppliers have suggested that
> > the soil may have a pH problem and that we should use iron sulphate to
> > correct it; but we think the near death of the cauliflowers suggests there
> > is some other problem."
> >
> > Since the paragraph above was written, the lavender has also started to
> > "droop".
> >
> > Soil testing revealed the following results:
> >
> > pH in water = 6.2; pH in CaCl2 = 5.0; Ec = .09
> > Na = .13meq%, 3% of ECEC; K = .44meq%, 10.10% of ECEC
> > Ca = 2.38 meq%, 54.7% of ECEC; Mg = 1.4meq%, 32.2% of ECEC
> > Ca/Mg = 1.7
> >
> > Phosphate - P = 92.2 mg/kg; Ammonium - N = 2.2 mg/kg; Nitrate - N =<2.5
> > mg/kg; Sulphate - S = <5 mg/kg
> > Iron = 90.5 nm/kg; Zinc = 5 mg/kg; Copper = 1.5 mg/kg, Manganese 7.7
> > mg/kg.
> >
> > While some imbalances were evident, the soil lab was not convinced that
> > the
> > problems were solely nutritional, and suggested that heavy metals or
> > pesticide residues might be the problem. The latter comment made me
> > wonder
> > whether any enviroweeders had experienced similar problems?
Hi Barbara
Myself I am very suspicious of the sewage sludge component in the soil
mix. Sewage is often processed these days and used as an organic
fertilizer or compost, but it is very difficult to ensure it is free of
heavy metals and quite probably pesticides as well, which can certainly
sometimes cause toxicity. Most people who aim to garden organically try
to avoid using it for this reason.
It would be interesting to see whether other users have had similar
problems with this mix.
You might have a valied claim for compensation.
Moira
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata,
New Zealand (astride the "Ring of Fire" in the SW Pacific).
