Soils Are Alive!!! Conference (Transcript)
Saturday 27th November 2010
Undambi Room Parliamentary Annexe Parliament House
Speakers:
Peter Kopittke School of Land Crop and Food Sciences University of Queensland
An Introduction to Soil
Dr David Eldrige University of NSW Microbiotic Soil Crusts and their role in soil and ecological processes
Associate Professor Peter McGee University of Sydney Mycorrhizal Fungi and their function in soil and application to restoration.
Dr Geoff Monteith QLD Museum Dung beetles and their efffects on soil.
Dr Geoff Dyne Australian Government Land and Coasts QLD Section A hidden diversity: native earthworm species and their role in soil processes and ecosystem integrity.
Dr Diane Allen QLD Dept of Environment and Resource Management Soil Carbon and Soil Health.
Merline Olson Soil FoodWeb International Soil carbon and soil health.
Professor Richard Haynes University of QLD Soil contaminants and bioremediation.
Dr Chengron Chen Griffith University Global changes and soil microbial community.
Moderators today:
Sapphire McMullan-Fisher.
Dr Thomas Baumgarten
There was a conference on Microfarming.
1.Peter Kopittke School of land Crop and Food Sciences University of Queensland An Introduction to Soil
He’s also in contaminated and remediated soil environments.
He wants to convince us that soils are worthwhile and worth knowing about.
He’s also in the Australian Society of Soil Science.
Soil is the interface between the living and the non-living. It is what connects the non-living the earth with us. Provides clean living water remediates wastes and pollutants and produces food.
Accounts for a ten millionth of the earth’s radius. Very fragile. 99% of our food comes from it.
Why are soils important?
For food. We build on it. Filter for water (surface and ground). Support biodiversity. Cultural value. Air water & soil cycle.
In one hectare of soil there are 100 sheeps worth of micro-organism.
Humans are managers of soil and as managers we need to lmit the degradation and maintain improve productivity.
Soil is the most valuable ecosystem in the worrld. Value US$20trillion.
Management of soil became crucial when society transitioned from hunting and gathering to agriculture.
What is in soil?
Mineral particles (inorganic fraction) – small particles of rock and other minerals produced from weathering of rocks
Organic materials – humus and the dead and decaying parts of plants and soil animals
Water – the ‘soil solution’ in which nutrients for plants are dissolved
Air – which fills the spaces between the soil particles not filled by soil solution
Living organisms – ranging in size from small animals to viruses
The nature and arrangement of these components influences the soil properties.
The mineral solids account for about 45%. Organic 5%. Water 20-30% Air 20-30%
By changing these proportions we can change the properties of the soil.
Properties of soils (most important. There are about 50)
Mineralogy texture
Colour (including mottles)
Structure
Organic matter
Water/ air
Texture is the proportion of sand silt and clay
Sand: 2.0 – 0.02mm
Silt 0.02 – 0.002 mm
Clay <0.002mm
Sand is not fertile soil.
They classify soils using soil texture triangle: Clay sandy clay silty clay sandy loam sand loam silty loam silt.
Simply by knowing the texture you can make all sorts of powerful predictions.
Minerals within soils aggregate together and have properties.
Texture influences:
Amount of water that can be stored in the soil (water holding capacity)
The rate of water and air movement through the sil (drainage permeability aeration)
the soil's nutrient supply (amount and availability)
Ease of root growth
Workability trafficability (potential for compaction)
Resistance to erosion
Ability of the soil to maintain a stable pH ( a remarkable property of soil is its ability to buffer changes in pH nutrients
Fertility of soils: A big topic
Clay particles have charge generally negative but sometimes in special circumstance positive charge. The charge enables soils to retain nutrients. Extremely important property enabling soil to have fertility. Called cation exchange capacity.
Sand doesn't have charge so nutrients leach straight through.
Structure:
Soil particles (sand silt clay) are usually arranged into larger units (called aggregates or peds)
Soil structure refers to the size and arrangement of the aggregates and the pore space between them.
Sand doesn't have structure. It is what we call massive.
Examples: polyhedral prismatic subangular crumb..
Structure influences..
Water entry into the soil
Runoff of water
Erosion
Drainage
and other things
Colour
Colour may be due to soil forming processes or inherited from the parent material
In general soil colour is determined by the amount and state of organic matter and iron oxides
Can give indirect information about other soil properties: organic matter drainage waterlogging potential degree of weathering leaching
Dark soil horizon almost certainly means organic matter. Red can absorb a lot of phosphorus drains well. Grey/blue-grey poor drainage and waterlogs periodically. Yellow...
Organic matter
Biological origin (dead plant and animal material)
Has a strong influence on soil properties
Reservoir of nutrients (esp NPS)
Contributes to cation exchange capacity of the soil (contributes negative charge)
Improves water holding capacity
Improves structural capacity of soil
Water and air
Total porosity = all the air spaces
A proportion is generally filled with water
The amount of water varies
Plants can extract varying amounts of water
Crop lower limit (Permanent wilting point 15 bas suction)
Saturation = full of water
....
A nation that destroys its soil destroys itself. President Roosevelt 1937.
[The damage that CSG mining is doing in the Darling Downs is just phenomenal.]
Soil is not an input but the foundation-stone of life.
We need a Soil Charter like a UN Charter in Australia. Particularly in reference to mining good agricultural land or building on good agricultural land.
Strategic Cropping Land Discussion Paper put out by QLD Government. There is a discussion now and soon there will be a decision about how to treat these very good soils. It is a very complex topic and we will have that discussion for a number of years until we find a solution to deal with demand and protect these soils.
Dr David Eldrige University of NSW Biological soil crusts: indicators of healthy soils
Dept of Environment Climate Change and Water
School of Environmental Sciences University of NSW
He's worked on biological soil crusts for 15 years.
Biological soil crusts are on the top few millimetres of soil and they contain a huge layer of microorganisms mosses...
Anywhere less than 500mm rainfall on gibber deserts we find cyanobacteria mosses. They provide a whole lot of essential services for soils.
Some of the best pastoral soils in Australia in Western QLD.
Typical view of a soil crust looks like scum growing on the surface.
You have to go close to see the crust is made up of individual organisms. 1-2 mm across.
If you look at a thin section through the soil the top few millimetres are lichen. Then algae and fungal hyphae grabbing onto soil particles to provide stability.
Mosses live hard and die young. They come up after rain. Large spores to regrow next time.
Many mosses have large stems to rapidly open up when wetted.
Arid zone liverwort is protected by black anthocyanin-rich scales to protect from ultraviolet light. Lichens contain lots of chemicals (very exciting to organic chemists)
Mosses have structures on their fillaments and lamellae that fill up with water.
Why are these organisms so important in our soils?
They assist water infiltration into the soil. A permeameter is used to measure how water moves through the crusts. The lichens and mosses provide little channels for water to infiltrate through.
They reduce erosion by water. If you've got a lot of cover you get very little erosion. Little cover you get lots of erosion.
Lichens create a rough microtopography with depressions to trap eroding sand grains.
Forests of mosses trap eroded sediment.
Soil crusts reduce wind erosion. If you've got a loamy soil you don't get a lot of erosion because the soil has inherant stability but with a sandy soil it is barely holding. If you keep a crust on sandy soils you protect against erosion.
Threats to biological crusts:
He's not going to talk about climate change because you could talk for years about that.
Trampling by sheep and cattle
Fire
Places that are close to water points (for stock drinking) have very little crusts but you get more crusts further away.
Fire destroys crusts by breaking down the gels in the polysaccharides. If you burn at a frequency of more than once every 10-15 years you will change the structure of the crusts.
Crusts recover very very slowly after disturbance.
Crust cover after 40 years at Maralinga nuclear testing still isn't back.
Way forward:
Monitoring to include the study of these small soil organisms in regular monitoring
Community awareness – education so people know why they are important.
Crusts provide a wide range of exosystem services
Crusts are good indicators of ecosystem health
They put carbon and nitrogen into the soil
Conservative or low-risk stocking is appropriate.
It is almost impossible to manage single organisms We have to manage ecosystems.
They vary in resilience. It is a matter of looking after whole landscapes (cars cattle and sheep burning).
Q. What are the implications for rotational cell grazing?
A. These crusts have co-evolved with our soils. Where we beat the crap out of them what comes back are not perennial grasses but annuals and exotic weeds. The model of destroying the crust to get plants back is not viable. We don't have a stable rainfall. We have a very variable rainfall.
Q. What about crusts in dunal ecosystems?
A. They are not really crusts. They are more like moss mats.
A. Mosses are associated with increasing water infiltration in the sand. Especially soil that normally repells water that is hydrophobic. They also stop wind erosion and become seed beds for the bigger plants.
Q. About rainfall parameters would any of them correspond with hard mulga?
A. Crusts are more highly developed as you go west (Charleville...) In southern Australia where Mediterranean climate controls rainfall there is a great diversity of crusts. As you go north to more summer rainfall get more cynobacteria dominant soils rather than lichen dominent soils.
Diverse crusts in Briggelow country.
Removing crusts or Briggelow causes crashing of carbon and nitrogen in the soil.
Professor Peter McGee School of Biological Sciences University of Sydney
Function of mycorrhizal fungi in soil
We have remarkable understanding of what goes on above the soil but appalling ignorance of what is under the soil. One of the biggest problems we have with soil is that we can't see what is going on.
We also can't feel or understand it because it is microscopic. And what is going on underground is scales of magnitude more important than above ground.
If we go below the soil surface we find that about two thirds of the living material is microbiological. Mycorrhyzal fungi make up by far the largest group of these organisms.
Mycorrhizas are associations between fungi and the roots of the plant. Fundi are fed by energy released from within the plant.
Two main types: arbuscular mycorrhiza (AM) and exto-mycorrhiza. AM typified by presence or arbuscule in cortical cell (require microscope to see)
Most plants are normally mycorrhizal. When plants grow normally you are usually unaware of the presence of AM
Absence associated with a variety of causes: major disturbance chemicals long fallow flooded soil.
AM is very important.
It doesn't just grow in the root system. It grows out into the soil..
Prior to sowing density of hyphae about 0.1m per g of dry soil.
Following seedling emergence 0.2m
Prior to harvest 0.5m
Uncultivated roadside 5m IN A GRAM OF SOIL!!!
Extensive ramification of hyphae through soil.
By disturbing the soil you are shattering the hyphae networks.
Implication of hyphal density:
Exploration of soil – mineral uptake and transfer to plant. Enable reach to areas that are simply unavailable to the plant.
They enable uptake of phosphate (non-labile) (which is deficient in all Australian soils) versus nitrate (labile)
Increased plant growth associated with increased P nutrition of plants. Normally no N transfer.
Soil inocculation with AM leads to bigger and healthier plants.
What happens when soil dries out?
The root uptake reduces rhizosphere water. Hyphae may bridge that gap.
Water remains within aggregates. Hyphae ramify through aggregates accessing water unavailable to the plant.
AM fungi have important role in plant water uptake and enable plants to tolerate drought.
Soil aggregation:
Aggregation is the process whereby soil particles stick together.
Two mechanisms apply: enmeshment (hyphae of AM fungi and fine plant roots) and adherence (glues from fungi)
Most stable aggregates are small. Least stable aggregates are large. Carbon stored in small aggregates.
The hyphae bind the aggregates together. Down at the 200microns the hyphae enmesh and hold it firm.
Adhesion is more important for micro-aggregates and enmeshment for micro-aggregates.
We have enmeshment and we have gluing (polysaccharides) They enable the adherence between particles providing a chemical bridge. Adherence is incredably important at this scale (200 microns).
If you are thinking about soil function you need to be thinking about putting something in that aggregate if you want to restore soil carbon.
When you cultivate soil you expose to air and you lose functionality.
The key to understanding functionality is at the microscopic scale. The carbon is held in the microscopic environment of the small aggregate.
His role is creating topsoil from mine material. Ghastly.
The key to aggregation is porosity. A good soil will have complex porosity as well as good aggregation.
Spoil from mines + variable compost (6% by volume) +/- AM fungi
After 6 months growth he wet-sieved to separate out aggregates by sizes and % distribution.
With a plant in with AM fungi macro-aggregation increased (large aggregates). Not so much micro-aggregation.
Water-holding capacity after 6 months with plants and AM fungi was 18%. Adding compost shifts dramatically the water holding capacity. Adding plants you increase water holding capacity. Adding plants and compost and AM fungi you increase water holding capacity. It is starting to create topsoil.
It is not enough to add AM fungi. You need plants compost and AM fungi.
Literature says glomalin is a putative glycoprotein released by AM fungi – after 8 years of looking at it he has absolutely no evidence to support this.
Other sources of adhesion? Fungus growing thorugh mine spoil Penicillium niveus produces a biofilm or gel. That gel can be separated out and put into mine spill and shown to form aggregates. Approximately 1% of fungi produce these gels. Any old microbe won't do. We need to start selecting the microbes.
We also need a fungus that has its own source of energy. We are now using endophytes and producing biofilm.
Addition of compost or sewerage to soil results in initial growth of plants but soil slumps as OC used. Soils become brick-like.
We will include 20 different AM fungi from the district.
Soil function declines in the absence of any one of plants compost and AM fungi.
Q. Can you buy these fungi?
A. No you can't buy them. They can't be cultured in the absence of a living plant. There is a commercial source but it is not working.
A. Don't dig your garden too often. You probably have adequate supplies in your garden. Don't disturb the soil too much.
Q. Is the no-till method a better method?
A. As far as the mycorrhizal fungi are concerned yes.
Q. How often to dig?
A. Never.
Within 6 months what's in that soil is likely to come from the growth of plants and their associated microbiota. The compost you put in the soil will have gone up into the atmosphere as CO2. The plant and the mycorrhyzal fungi will have drawn CO2 down from the atmosphere as they grow and fix it in the soil.
Probably both compost and sewerage will be quite successful.
Q. Sewerage has high levels of pharmaceutical drugs and is dangerous?
A. Rubbish. They are in anaerobic form. As soon as they are exposed to air they degrade quite quickly. If we are talking about drugs in water we have a different situation because of the lack of oxygen. But in oxygen drugs break down quickly.
Apparently if you put compost in the soil none of it remains after a while. It has all gone to atmospheric carbon.
In the meantime the plants and mycorrhizal fungi growing in it have been drawing down atmospheric carbon and stabilising this carbon into the soil.
Dr Geoff Dyne Australian Government Land and Coasts QLD Section A hidden diversity: native earthworm species and their role in soil processes and ecosystem integrity.
Very popular but little known about their diversity and function in the native environment.
Charles Darwin first studied earthworms and produced in 1881 his last book: The Action of Earthworms in the Production of Vegetable Mould. He observed a piece of fallow land that had been marshland with ciders and limestone stuck on top. After 15 years worms had completely buried it by coming to the surface and depositing their castings dropping the surface a good 15 inches or so. He studied widely and came to the conclusion that earthworms were responsible for gradual subsidence of stone structures. Earthworms responsible for 10 tonnes of bioturbation in a year. Moving it around physically.
What are earthworms?
The phylum annelida was traditionally divided into polychaetes leeches and earthworms and allies.
Characterised by having segmented bodies setae and a clitellum which secretes coccons.
Two major families in Australia megascolecidae and ....
Australian earthworms have been here since before the break-up of Gondwana and have co-evolved with Australian soils.
Tend to be highly endemic (often localised) gene flow is very slow.
Have adapted to low or uncertain rainfall through various means
Have co-evolved with the unique Australian flora.
Having been here so long they have adapted to all the vagaries of climatic change.
Generally accepted you don't get them beyond the 650mm rainfall zone but you can in isolated pockets
There are some 750 described species in Australia of which about 30% are in Queensland because this is where the most work has been done.
The true number of earthworm species in Australia is unknown but may exceed 2500
They occupy a very diverse range of natural habitats including sand-dunes alpine bogs tropical rainforest and savannah
Exotic species are prevalent in urban and other altered landscapes and are spreading. QLD has more exotics than any other state.
One South American species Pontoscolex corethrurus may be having a deleterious impact on native forest sytems.
Not all earthworm species are equal or perform the same function. It is a fallacy that all earthworms are interchangeable.
Hermaphrodite. They both inseminate each other at the same time.
Main species around Brisbane:
Digaster
Heteroporodrilus
Spenceriella
Plutellus
All the earthworms we dig up in our backyard are not native species performing an ecosystem function.
Digaster anomalus is the most common in Brisbane.
Current distribution represents this legacy of expanding and contracting populations over long periods together with local evolution and extinction.
The shield volcano and the erosion of the caldera has resulted in a massive number of species.
The MacPherson-Macleay overlap is where northern and southern faunas overlap. Species and genus-rich area.
The Bowen Gap in central QLD limits earthworms.
The Briggelow belt has its own distinct associations. They estovate and see out the dry times.
Functional classification is based entirely on northern hemisphere species. Some parts are relevant and some just don't make sense.
Endogeic worms build complex lateral burrow systems through all layers of the upper mineral soil (the ones you most often encounter when digging)
Anecic worms build permanent vertical burrows that extend from the soil surface down through the upper mineral soil layer (the night crawler pulls whole leaves down into its burrows. They recognise their own burrow)
Epigeic species live in and feed in the organic surface debris and are poor burrowers.
It is interesting to speculate whether earthworms can break organic matter to break down . More likely they rely on fungi to break it down in their gut. They have a tremendous role moving material around and producing micropores for the infiltration of water.
All the work about producing aggregates and breaking material down is done in the northern hemisphere. We know nothing about this here.
Vertical habitat partitioning in Australia
Xylicolous spp associated with decaying timber
Litter species often very small occupying the interface between decomposing litter and the A1 horizon
Upper soil species most frequently collected form burrows mobilise organic matter
Subsoil species – sometimes large deep-burrowing often feeding on bacteria (not anecic in the European sense) Rarely see. Only after heavy rain or when earthmoving equipment pulls up the deep soil.
They asphyxiate in heavy rain because they need oxygen around their body.
Ecological function:
Primarily decomposers – mobilise organic matter into the soil where it is more readily attacked by fungi and bacteria. Some species may produce cellulase
Mineralise organic matter to produce castings which are readily utilised by plants; nitrogen mineralisation of particular importance
Aerate soil through the formation of macrospores..
Transport...
We know very little about what we are doing with earthworms introducing exotic species.
All the worm farm species are exotics and they are all epigeic (live in the surface layer).
Q. Bruce Ham. What are the positives and negatives of worm castings for improving the soil.
A. Absolutely no problem with those. Also worm juice (a diluted form of their urine). Only word of caution is where exotics are introduced into undisturbed native bushland. Castings perfect for introducing significant amounts of nitrogen back into the soil.
Q. Where zero-tillage is used which requires the use of herbicides they get far more earthworms than under conventional tillage.
A. Yes a lot of earthworms are close to the surface and prefer to be undisturbed. The jury is out a bit on the impact of herbicides on them. They can take in vast amounts of heavy metals radiation ... A lot of earthworm species have been used for environmental restoration because of their ability to transport and remediate harmful substances.
Q. How to identify species?
A. Send to Qld Museum. If they can't identify them they'll send them to Geoff. We're losing a lot of our expertise in earthworms. Students are moving from whole animals to DNA and they can't recognise whole animals!
An earthworm that twitches and bounces around when you touch them is an exotic for sure.
Dr Geoff Monteith QLD Museum
Dung beetles and their efffects on soil.
Most plant material goes through an animal at some stage and comes out as dung. Great for soil but most animals plonk it on the surface so we need some way to get it into the soil.
Experiment:
Seeds
Seeds and dung beetles
Seeds and dung
Seeds dung beetles dung
Grow for 6 weeks. First 2 weedy seeds and dung better but the seeds dung and beetles very lush.
Dung is good and dung is better if you've got dung beetles to go with it.
Beetles are the most successful group of animals on earth. They are winged insects. Wings are fragile but beetles invented the way to protect their fragile wings and still bore into wood and ground.
Dung beetles are scarab beetles with antennae at the top. The ends of the antennae open up and help them smell directionally. They fold up when they burrow. Super antennae which make them very good at finding locally bits of nutritious food. Dung beetles are a subset of scarabs.
Dung beetles eat dung themselves but mostly they use it to feed their young. Adult dung beetles don't have functional mandibles to chew. They just want to slurp up the gravy part. The grubs do have mandibles to chew.
When they arrive at a lump of dung they burrow into the soil under it and roll a lump of dung down into it and lay eggs in the chamber with the dung. The dung pat on the surface is all buried.
With 500 beetles under a cowpat it is busy under the ground. The more advanced beetles role it into a ball away from all the activity to a private place to bury it and disperse it.
Most of the native dung beetles here are in the genus onthophagus. About 170 species of dung ball rollers.
There are some cuckoo dung beetles that don't make their own nests but kill the nest-maker and lay their own eggs.
There's a species that likes to feed on rotten mushrooms.
The most amazing dung beetles on Earth occur in se QLD and northern NSW. They leave out vertebrate dung and make their own dung from composted leaves they pull down. The mother defecates into it and innoculates it with fungi that turn it into dung. The populations are aboaut 50000 per hectare. One species is right here in a bushland reserve in Brisbane. They pull huge amounts of leaf litter down into the ground.
Australian dung is often very hard and dry. There are a group of beetles that have adapted to hang onto a kangaroo's bottom so they can grab the dung as it emerges to get to it while it still has any moisture!! Agile wallabies have up to 20 or 30 of these clustered around their cloaca.
Onthophagus dandalu is Brisbane's doggie doo beetle which really loves to clean up dog poo.
Aulacopris maximus specialises in using the dung of bats.
Males of dung beetles often have horns. Partly to fight among each other for females but more often to defend the burrow while the female is down below laying eggs.
23 African dung beetles have been introduced to Australia...why?
Native dung beetles evolved to use dry macropod dung.
They cannot cope with large moist piles of cow dung
So cow dung persisted unburied on the ground surface
Therefore beetles that evolved with similar ruminant animals in Africa were brought to disperse cattle dung into the soil.
Lots of deleterious effects of having dung lying on the surface. Cows drop 10 pads a day. They don't like feeding near it. It reduces the area to feed. The nutrients waft away and the fibrous bit just stays on the ground. Persistent surface dung harbours intenstinal worms. Every time it rains they migrate out onto pasture and cycle back into the cattle. Flies breed in dung.
Onthophagus gazella is the most common introduced African dung beetle – a burier.
The African ball roller is Sisyphus spinipes.
You'll see these in the middle of the day. The native ones are all nocturnal.
Dung beetle surveys. They are a key group for biodiversity surveys.
Easy to survey with traps baited with dung
Easy to identify
Many parallel global studies in progress
Much baseline information available on species distribution
Sensitive to environmental factors
Linked to vertebrate fauna.
QLD Museum has 110 drawers of 75000 databased specimens.
Good rainforest cover. Good Brisbane cover.
Baited pitfall. A plastic cup sunk into the ground with bait in it. Put a raised plastic cover against rain.
Surveys have identified 63 species in Brisbane area 28 native 4 African.
Q. Are dung beetles linked closely to particular vertebrates and are they lost when those species go?
A. Most dung beetles are not linked closely to particular vertebrate species except the bat one. They are more linked to dung types.
There are plenty of species in sclerophyll forests. They are more diverse for dung beetles in open forests than rain forests.
Q. What is the effect of livestock drenches on adults and larvae?
A. Don't know too much but Invermectin is known to kill the beetles when the dung comes through the cattle.
Q. Do they have predators?
A. Ground-foraging birds which is why the strategy for a lot of them is to become nocturnal. Cane toads sit on top of cow pats and eat the dung beetles. Ibis love them too.
Q. Dog poo in suburban area. How do we maintain the beetle that eats it when we are supposed to be picking the dog poo up?
A. That beetle is very catholic in what it will eat.
The greatest thing that knocks back the dung-beetle population is the weather (drought).
Merline Olson Soil FoodWeb International
Soil carbon and soil health.
How to measure soil biomass.
She's a soil microbiologist.
They measure the life in your soil.
The methods:
Activity – fluorescein diacetate
Total biomass – the original method against which ALL other methods are checked
Protozoa soil agar MPN. No other method assesses ALL groups of protozoa
Nematodes – active or total extraction.
The question is what do you want to know.
As you go up in biomass numbers you also go up in species diversity.
How do we know what biology is needed in the soil?
What does the plant need?
The ratio of fungi to bacteria is what changes.
Early grasses bromus bermuda F:B = 0.3
Mid-grasses vegetables F:B = 0.75
Late successional grasses row crops F:B = 1:1
Weeds F:B = 0.1
Cyanobacteria true bacteria protozoa fungi nematodes microarths F:B = 0.01
Shrubs vines bushes F:B = 2:1 to 5:1
Deciduous Trees F:B = 5:1 to 100:1
Conifer old-growth forests F:B = 100:1 to 1000:1
It's not just the ratio. It's the number of species too.
They use direct microscopy looking at the organisms and counting them directly. They do an epifluorescent stain to see them and count them and to be able to talk about the quality and diversity of the fungi in that system. Who is actually in their to back-calculate what is in the soil.
She is pleased that it was said there is no-one in Australia able to produce mycrorrhyzal fungi for our soils commercially.
How do growers know what is needed?
If you want to grow mid-grasses and you test the soil and find F:B = 0.3 then you are back a stage and have to get the ratio up.
They do a workshop teaching how to make compost how to make compost teas - an innoculum a batch-culture that you can put out on to land if we know that the land needs that.
Bacteria:
Build soil structure – micro-aggregates
Nutrient retention
Disease suppression
You'd really want replicated samples (enough of them) to start to get validity in the measurement.
In a bacteria colony who is actually working metabolising gluing itself to organic matter. Compare it to the total biomass.
As with fungi there are the wrappers and the binders in putting the structure together.
Is there enough fungi growing to be able to increase the binding in the soil or do we need to add some foods?
We're looking at the quantity and qualtiy with direct microscopy.
In compacted soils we get the depletion of oxygen and the anaerobic bateria can come in and consume our fungi.
Protozoa:
Single celled organisms that primarily consume bacteria and release nutirents...
We want to get the numbers and the diversity
Amoebae flagellants
Active amoebae can consume 10000 bacteria per day!
The plant is in control. She's the one who's putting the food in the soil to provide the beneficial organisms it desires. It feeds beneficial organisms to bring the plant what it requires.
A sylviant is another type of protozoa. Is there enough oxygen in the soil to get nutrients down? If oxygen is low this little critter will show up in large numbers.
Is this enough N to grow plants?
5 N released for every 6 bacteria consumed
Nematodes:
How much are there? The root-feeding nematodes are just one of the species that will feed on the roots of the plants if there is not enough bacteria to eat.
Very similar to the ocean floor and the little fish and the big fish.
The right biology enhances functions
Disease protection
Nutrient immobilization to reduce leaching
Nutirent availability
Deocmpostion
...
How deep is soil?
Compost is not just organic matter. It contains 95% organisms. Active bacteria: Total bacteria
Active Fungi: Total Fungi Active Fungi: Active Bacteria
info @soilfood.eb.com
02 6622 5150
SFI in Lismore
Q. Compost tea. I understand farmers are applying 100 litres/hectare. It is har