Wednesday, 29 November 2006

Look After Your Natural Assets

The Upper Murrumbidgee Catchment Cordinating Committee in conjunction with Landcare recently produced a revised edition of its "Look After Your Natural Assets" landcare booklet. This is a pretty neat publication for anyone who happens to have an interest in small blocks of rural land (or even big ones in my view), and covers a whole range of subjects such as plants, soils, water, conservation, management, revegetation and contacts.
Copies can be obtained (for free!) via email to

Friday, 10 November 2006

View Satellite Imagery of NSW Free

In this morning's edition of The Weekly Bundle produced by the Lachlan Catchment Management Authority the following article appeared:

"View Satellite Imagery FREE
The Department of Lands (DOL) have recently published whole of NSW SPOT 5 satellite imagery on their website. You can link to this free site via the web address below and click on the Imagery tab., then "click here" under Lands Spatial information exchange to see the Spot5 images.

You may have to download some small image viewing software that will allow you to view .ecw images, but after this is installed, you can view any Spot 5 satellite image in the state. The response is impressively fast and allows you to view your farm, your town or your catchment."

I spent a bit of time checking out the site and was pretty impressed with what's available.

A user can search for locations based on aspects such as Address, Lot/DP (this is what works the best for finding rural properties I think), Catchment Management Authority, Suburb, City/Town/Suburb and Local Government Areas.

There are also several different display images on the landscape available, such as colour satellite photographs, topographic maps, Landsat Imagery and Multispectral satellite imagery. I confess that I do not understand what these last 2 are ... but would like to ... the different coluors of the landscape are quite marked and raise many questions in the context of making land management decisions.

Readers living outside NSW who would like a property to check out can email me at and I'll give you the Lot & DP (Deposited Plan) numbers for Ochre Arch to work with.

Thursday, 9 November 2006

Are Organics Fruit & Vegetables Better For You?

Glen, my personal gym trainer from Bennettswood Fitness Centre, was telling me about a show he’d seen on TV recently where tests were done to see if food grown organically was ‘better’ than conventional grown produce. A further comparison was done to see what the impact of freezing fruit and vegetables was. The main outcome of the tests was that overall there was no material difference between the 2 – which was a surprise given all of the talk about the need to move away from chemicals. He sought my thoughts on the subject and I confess to not being of much assistance.

After the training session with Glen I contact Carolyn Ditchfield, a friend who owns the soil health business called “From the Soil Up” based at Inverell. Carolyn has done quite a bit of reading on the subject of soil and food health. We’d had previous discussion where she’d enlightened me on the need for “minerally dense” foods and I wondered whether this was an important measure. She sent me an excellent email outlining her ‘top of mind’ thoughts on the subject of organic V conventionally grown foods. After reading it I sought (and was granted) her permission to create a post on my blogsite outlining her main points. These follow.

Carolyn’s Comments on Organic V Conventionally Grown Foods
“It really goes back to the definition of ‘organic’ – was it ‘organic by neglect’ (i.e. don’t do anything and it can be labeled organic)? Also, there are some organic growers out there, purely in it for the premiums, or simply have poor soil knowledge.

The unfortunate thing with many of these studies is they are often conducted with a background bias in play – was it the conventional industry trying to prove a point (the same happens with it is the organic industry trying to prove a point)? You really need to check out who conducted the test and more importantly how they selected their test foods, was it measured dry matter basis or wet weight (i.e. fresh) etc.

Yes, minerally dense is the term often used, but it doesn’t take into account the form or ratio of minerals and/or enzymes, amino acids etc which is often more important – going back to basics, flavour is the biggest determinant and the good old ‘Brix meter’ gives a reasonable gauge on that for those of us that are not overly sensitive to slight variations.

Freezing will not change the mineral content significantly, but does have quite an impact on enzymes etc – which as stated above can be even more important for health giving properties.

As for chemical residues – if the chemicals were solely used externally – yes, you can rinse of some of it, but most are applied with oils and other artificial surfactants, so water alone barely does anything, you need to use some form of detergent to really move it. But the biggest problem is that most the chemicals now used in the horticultural industry are systemic, i.e. they move internally via the sap and become part of the fruit of vegetable – and there is no way to rinse those off. It is stated that given enough time after the spray the fruit will breakdown the chemicals – but that is a bit of blind trust really, you never really know, but the most alarming part is that while they claim to have regulations preventing contaminated fruit being sold through registered fruit markets. Apparently since the regulations were introduced in Brisbane’s Rocklea markets at least a decade or more ago there has not been one prosecution. Yet I know of one story of a university lecturer feeding his canaries lettuce from the markets and killing them all. He took the lettuce to the university laboratory and identified the chemical – not a happy chappy! But it also says something about the enforcement policy and our safety. I also know of many farmers that have sprayed just prior to sending veggies in.

I would still choose organic over conventional in most cases.”

Contacting Carolyn
Landholders interested in learning more about soils and soil health can contact Carolyn on email:

Post Script
I’ve subsequently learned that the TV program Glen watched was called “What’s Good For You”. It screens 7.30 pm Mondays on Channel 9 and is hosted by Sigrid Thornton. The program has a web site at The web site provides detail on the episode where the topic “Are Organics Fruit & Vegetables Better For You?” was discussed. See for these details.

Monday, 6 November 2006

Wildlife Observations on the Gold Coast

After receiving and reading our latest Ochre Archives Newsletter long time family friend, Athol Hodgson (who lives in the Gold Coast Hinterland) sent me a very informative email sharing his observations on the wildlife in his area. I subsequently sought and was given Athol’s permission to publish the main points in his email as a “guest Blog” which is what this now is.

You’ll notice when reading Athol’s comments that among other things he has observed a significant decline in the number of Magpies. This seems particularly curious. I suggested to Athol that perhaps the cane toads might have had some impact (due to the poisons that are in glands on their backs) and I also embarked on a bit of investigative research to see if I could find someone who was able to provide some scientifically based thoughts on the change.

On the research front, I contacted Toni McLeish, who works for the NSW Department of Environment and Conservation and coordinates the Grassy Box Woodlands Conservation Management Network. Toni kindly referred me to Greg Ford who is the Regional Coordinator - Vegetation and Biodiversity for the Queensland Murray-Darling Committee based at Toowoomba West. Greg in turn expressed interest in the case recommended that I approach one of the following groups:
* Birds Australia -
* Birds Queensland -
* Centre for Innovative Conservation Strategies, Griffith University –
* Assoc Prof Darryl Jones (at above centre) is an expert on wildlife in urban areas

I opted for Darryl, and received a very helpful and informative response, the main points of which also appear below.

Athol’s Observations
“Although I've not taken the time to do extensive studies of birds and animals, I am fascinated by them. Where we live here in the hinterland we are fortunate that there is an abundance of birdlife, particularly along Mudgeeraba creek, which is just a few hundred yards from our house as the crow flies, and the crows outnumber all the others put together. In fact, the entire Gold Coast is home to thousands! At Nobby Beach for a time, and I was amazed at the number of crows there. The first thing I noticed upon arriving on the Gold Coast was that the crows here have a different call. It is short and clipped as opposed to crows down South, and in the West. This, despite the fact that my brother told me a crow was caught in Greenethorpe (near central NSW), and was found to have a tag which was attached in Darwin! Are some crows migratory?

Here we see wattle birds, lorikeets, peewees, butcher birds, currawongs, (though not as many now for some reason). Ibis are also in abundance, and they have become a nuisance in recent times, being real scavengers. Down on the creek there are crimson rosellas, eastern rosellas and king parrots.

Magpies have largely disappeared, don't know why. Up until two years ago there were thousands. I am skeptical about the cane toads decimating them. If this was so, surely they wouldn't all disappear at once. Some three years ago we were visiting Tamworth, and at that time there was literally a plague of magpies, who hung around for a couple of months, then vanished, except for a few who stayed. We actually have two or three pairs here at present, but I have seen no young ones. I have found that they start nesting in August, and that applies to the bush where we lived, in Sydney, and the Gold Coast. However, I have not seen any young ones this season, whereas there was some last year.

Water dragons abound along Mudgeeraba creek.

We have been delighted to see the return of green tree frogs, but they only emerge after rain. Two nights ago there was a light shower and I spotted one on the back step. And three weeks back I went to water the plants (water restrictions now decree that we only use water cans) and I wondered why the water wouldn't come out. I found a green frog in the spout!

At a one acre block just five minutes from us, there are cockatoos and a family of plovers, which intrigue me, as they nest on the grass, not even in a hollow, and with no nesting material .Last summer they nested three times, as predators of some kind kept swiping their eggs. They finally managed to raise one chick. Large wood ducks can be seen almost daily on their land, and last summer a pair of crows nested in a tall gum tree just outside their front door.

Just after dark a couple of weeks ago near home a fox crossed the road in front of us. The sad thing is that development is going on at a great rate all over the coast, which means loss of habitat for many.

This morning I encountered my first cane toad for this season. They haven't been around, no doubt because we have had no rain to speak of. As with snakes, a lot of myths surround them. One story which I don't believe is that they spit deadly venom when cornered. In 1970 in North Queensland I encountered an average of six every night. We had an outside toilet there, and my wife wouldn't go down until I did the surveillance. Not one ever spat at me.

Last summer we were at my partner’s daughter's place- and there were hundreds of tiny toads in the grass. I suspect that the birds prey on them as they say the small ones don't have any venom. I recall the teacher at the Greenethorpe public school telling us about cane toads. That would have been about 1943, and as you know, the toads were introduced to control pests of sugar cane. As with most introduced species, this move was disastrous. Take the Indian Mynah. Sydney now has a plague of them.

Something else that I have discovered, when we were living in Meadowbank on the banks of the Parramatta river I befriended a pair of butcher birds, which I tamed fairly quickly and had them literally eating out of my hand. I read about them in two different bird books, and I found that a pair of birds occupies a certain area, and no other butcher birds are allowed there. However, the books didn't mention that every pair has a different call, unmistakably butcher bird, but a different melody. I discovered that very quickly. During our stay there, over about five years, I watched them nest each year, then was fascinated when the fledglings left as soon as they could fend for themselves. How they found an unoccupied area to move to I don't know.

Last night, upon arriving home in the dark, I spotted two small geckos under the eaves outside our garage. I've not seen any before. There are usually two per house I'm told.

I have always loved pelicans, and they are in abundance on the Gold Coast. You have no doubt heard how the pelicans that frequent Lake Eyre desert the lake as it dries up during drought, heading for the coast. Then when the rains come and the lake fills again, they fly back. No-one knows how they can work out that the lake has filled again. Another aspect of pelican life intrigues me. I have only ever seen adult birds. I just went into Google and accessed 'Pelicans' which tells me that the birds nest in secluded spots or on islands. The young stay in the nest for a month and then frequent a crèche for a further two months, when they join the adults. I have yet to find just where they nest, having visited secluded spots and islands.

When we came here four years ago, there were hundreds of lorikeets coming into our back yard each morning. We have grevillias growing outside our back fence, and they love to get the nectar from these. However, despite the fact that the grevillias had an abundance of flowers in spring, the birds have largely gone. It is now rare to see one pair. Curious!”

Assoc Prof Darryl Jones Thoughts on Athol’s Magpie Observations
“My first impression - is that the impression of a major decline in magpies is very likely to simply be an impression (!). They are one of the relatively small numbers of species that have thrived in the wake of urbanisation, while lots have disappeared. However, there are some current issues that could certainly be affecting things in a specific location. The first is that these birds are reliant on friable soil and short grass to obtain almost all their food. So when drought continues and the grass dries and the ground hardens they are in trouble. However, these birds also maintain their territories for life and I cannot imagine any natural conditions that would force them to leave their patch - apart from concreting the whole thing over.

And these territories are the exclusive domain of a single pair and whatever offspring may be hanging around since last breeding season. No other individuals are tolerated on these spots - unless, as sometimes happens, someone is feeding lots and the territorial system breaks down in the vicinity of a particularly rich scavenging site.

I am aware of some situations were people do poison birds - usually crows - and magpies are hit inadvertently.”

Saturday, 4 November 2006

Impact of Lawn Mowing Height & Frequency on Plant Root Growth

At the beginning of last month I posted an article on this blogsite titled Growing Lawn Without Watering. In response, one of the readers (Peter B.) commented: “Liked your article on grass …. I was under the impression the more frequently the grass was cut (at maximum height setting without catcher) the stronger the root system … maybe this is an urban myth?”

Judi Earl is an Holistic Management Certified Educator based at Guyra who has a strong scientific background in pasture growth and the interaction of pasture and animals. She and her business partner Lewis Kahn collectively own and operate Agriculture Information and Monitoring Services. I contacted Judi and sought her thoughts in respect of Peter B’s question, and her enlightening response is below:

“There is huge potential to improve water cycling if city folk realised the impact they could potentially make by improving all their collective small patches of land.

I've no doubt that mowing at maximum height enhances root growth and improves the persistence, vigour and health of lawn species. On average for pasture grasses cutting, or grazing, to leave a residual height around 5cm will not result in any damage to root systems. Leaving this amount of green leaf enables the plants to regenerate leaf from energy derived from photosynthesis without the need to draw energy for regrowth from the roots or crown. Obviously the actual ideal height for cutting will vary between species some may be able to be cut lower than 5cm without damaging root biomass and some will likely be favoured by higher cutting but 5cm from my reading appears to be the average.

Certainly in the defoliation experiment I conducted some years ago defoliation to 3cm height reduced root biomass. Plants cut to this height every 2 weeks had about half the root biomass of those cut every 4 weeks and these had half the root biomass of those cut every 8 weeks. I had 8 species in the experiment and this effect was apparent in every one. By cutting less intensively (leaving more residual) plants actually grow faster and may be cut more often without impeding root growth. This has all the benefits you so nicely describe in your blog.

If it happens that you get good soaking rain to really wet the soil profile to depth during the growing season you could potentially take the opportunity to give the lawn a good close trim. This will enhance the turnover of root material (organic matter) in the soil and with good soil moisture conditions the regrowth ability of leaf material and new roots will be enhanced.

That's what I do with my lawn although I have a sort of leader follower thing happening occasionally. I often get a couple of days grazing for my old horse every now and then and then follow the next day with the mower. The mower also spreads the manure nicely which speeds up its breakdown and evens out the height. I've been doing this for a few years now and this spring my lawn isn't aware of any drought and I've a whole new suite of different species appearing.”

My thanks go to Judi for sharing her knowledge, and also for giving me permission to publish her comments. If anyone would like further information you can contact Judi via email at