FAQs

Frequently Ask Questions (48)

Q1. Can you have ‘bad’ or too many of a particular soil microbe present.

Answer: Not really. There can be an imbalance among species because of external sources of not necessarily appropriate fertilisers, etc. For example, when high levels of salts are applied eg Ca or PO4, then there is a big increase in those species needed to deal with this chemistry. Eventually the populations will return to environmental levels. If the full soil food web is present, then members of the population will utilise excesses in some species and release plant available nutrients for plants to use. It is generally only a soil in trouble that has an imbalance of microbes.

Q2. What planning or preparation is needed in deciding on the soil sample site? A paddock/small plot? Random.

Answer:  Sampling is based on soil type; vegetation types indicating a change in the soil; elevation. Soil on hill tops is different in composition of sand, silt and clay from the soil in the alluvial flats and the biology will also be different. By knowing the differences in your land and vegetation, sampling is carried out based on those differences because the management programme will be different to maximise soil health and productivity. Once the areas are understood, then sampling should reflect the block or paddock. Thirty 10cm cores can be collected in an X shape across the block or a W shape to represent the whole area. Mix these cores together very well and choose a representative 1kg of soil. This can be sent for chemistry testing and for biology. This first set of reports forms the base line chemistry and biology and helps to understand what needs to be done to get the soil biology functioning for maximum productivity regardless of the enterprise, cultivation or grazing

Q3. Aerobic vs anaerobic, organisms, good vs bad, ratios? Relationships?

Answer: Generally aerobic microbes are what you are looking for in the soil. Some important bacteria are anaerobic and photo synthetic and form part of the soil food web. Anaerobic conditions can produce unwanted toxins which negatively impact on good soil biology. It is better to have good air flow through good soil structure which will stimulate the fungal population that will benefit plant growth and soil health.

Q4. I want to ensure healthy soil and healthy plants by monitoring soil biology, particularly mycorrhizal (ecto & endo) fungi which from my current practices seem in short supply.

Answer: Different plant species have endo or ecto but very few have both. Some plant types do not have mycorrhizae at all. Look at my website for lists of plants having different types of mycorrhizae www.agpath.com.au. Cultivation or constant disturbance of the soil will deplete the fungal population through constant breaking up of the fungal hyphal mat in the soil and on organic matter. Adding salts such as super phosphate will badly affect fungi as will metals such as copper often used for disease management. Peer reviewed scientific literature can be found from around the world to support this effect. Have soil tests carried out at appropriate times of the year and modify management practices to minimise damage to the soil biota. Use good quality thermal aerobic compost and compost teas. Look to biological products in place of commercial chemicals. Minimise disturbance to the soil and keep organic levels up to encourage fungi. Permanent grass pasture is a good source of mycorrhizal fungi.

Q5. What edible saprophytic fungi will grow on Eucalyptus chips of sawdust? King Stropharia?

Answer: Mushrooms can be seen growing on wood chips where the conditions of moisture, shade and organic matter are available. Make a trench and fill with pre-wet straw and hard wood chips. Mushroom spawn can be purchased and added to the trench. Cover with more straw and wood chips and firm down using a piece of timber to walk on. Make the spawn bed in spring, keep the trench moisture and cool and fruiting bodies can appear in autumn.

Q6. Will participants have access to CMA/DPI testing and knowledge of all soil elements, eg pH kits?

Answer: Each CMA has access to most information required by participants. pH kits can be purchased from good gardening stores. Soil chemistry and soil biology can be explained generally by consultants in the field. Agpath P/L consultants at agpath@dcsi.net.au can be of assistance.

Q7. Can we arrange soil tests (eg phosphorus, Mg/Ca balance ect) to link to microscopic analysis of soils/paddocks?

Answer: When a soil sample is collected as described in Q2, part of that sample should be sent for chemistry and part for biology testing; Agpath P/L provides that service. A report can then be generated linking the chemistry and biology and a management protocol developed if that is the outcome desired by the farmer.

Q8. Variation in nutrient availability with microbe change? Effectiveness of microbe activity on root growth?

Answer: The most microbial activity is in the rhizosphere (area of soil immediately around plant roots) where plant root exudates provide nutrients for the microbes and they, in turn, supply nutrients from the soil the plant roots. Soil type and soil pH are more likely to affect availability of important macro and micro elements. Soil pH can be adjusted using good compost where the microbes will then function to supply nutrients in plant available form. An active and fully functioning soil food web is not present in poor soil so improving the soil with compost and natural organic matter will allow the soil food web to function effectively and provide nutrients needed by the plants resulting in healthy and productive plants producing nutritious crops whether it is good quality grass for stock or tasty vegetables.

Q9. Producing comparable data (soil health sheets) and learning to use soil indicators in management and decision making.

Answer: Soil samples should be taken at times in the growing season where most advantage can be made of management changes, often spring and autumn. Once times have been established as being the best for your enterprise, then take future samples at the same times each year. This way the results can be compared from year to year. The indicators in the soil food web should be explained with each report.

Q10. What is soil biology?

Answer:Soil biology is a term using to describe all the organisms in a good soil. In the chart below you will see the many levels and interactions that occur naturally in a fully functioning soil food web. It is getting these all functioning providing healthy plants with the nutrients they need that is our philosophy in biological farming. Minimising or removing commercial chemicals from the soil management programme is a good start. Adding amendments to good aerobic thermal compost is a better way of adding chemicals to the soil. Learn to use a simple microscope and use it as often as possible looking at soils, composts, compost teas, etc. Take electronic pictures and email to someone like me, Mary, at agpath@dcsi.net.au and I will give you identification. You can look for books to buy or use the websites through Google or any other search engine. There are great pictures, videos, etc on- line for you to search on your own. Another service Agpath offers is the closed part of the website where people who have participated in workshop s can join and submit their pictures but also have access to all the other pictures people have sent in and I have written an explanation of the content.

 

Q11. Large scale compost making and application at broader scales.

Answer: : Look at the website for Camperdown Compost Company where Nick and Tony are involved in making very good aerobic thermal compost. They are very helpful with their knowledge. Darren Morgan of Enviroturf Australia is another maker of good compost – enviroturf@iprimus.com.au.  Farming Secrets is another site that has DVDs, etc for maki ng compost and worm farming –helen@farmingsecrets.com

Q12. Relevance of adding fertilisers NPK etc to soil biology. What effect?

Answer: Any salts adding in large amounts will damage soil microbes to a greater or lesser extent. Metals such as copper will affect all fungi and phosphates have a negative effect on mycorrhizal fungi in particular. Mycorrhizal fungi have a role in the soil of scavenging for phosphates and supplying them directly in plant available form to plant roots in exchange for carbohydrates which fungi cannot manufacture because they are non- photosynthetic. Any disruption to this symbiotic relationship causes loss of mycorrhizal fungi leading to loss of soil structure and loss of water holding capacity. Look at literature in the journal ‘Acre’, J. of Soil Microbiology, and others, for peer reviewed papers. If you add 10% of the recommended rates of NPK to a good compost and then distribute the amended compost or compost tea to your soil, you will improve the soil without damaging the soil microbes.

Q13. To be able to do soil nutrient testing.

Answer: Soil nutrient testing is chemistry and requires a laboratory set up for that specific purpose. There are several in each state. The Environmental Analysis Laboratory at Southern Cross University, Lismore, is my recommendation because the testing was designed by the Laboratory Manager and Dr Elaine Ingham of the Rodale Institute in USA, to best reflect the chemistry needed to develop a biological farming system using her soil food web tests that are carried out my lab at Agpath P/L.

 

Q14. Healthy soil for livestock health and better production.

Answer: The pathway to healthy soil starts with having a complete chemistry and biology carried out on all the different soil types on the property. This data is considered along with the previous history of the property such as fertiliser input, grazing or cropping history; irrigation, flooding potential, etc. With all that information, a programme either of continued chemical use or a change to biological farming, either totally or in part, can then be designed. A commitment then to a management programme is implemented with a consultant. Evidence is widely available to show that animals are happier and healthier in a farming system that has minimal chemical input. Production can be higher and crop quality is certainly higher. Having all the information necessary to make the change is what is needed and that is available from consultants who work within the biological/organic system. I am always available to explain the science or to help with a programme.

Q15. More about fungus in our soils. It is giving problems after the recent high rainfall.

Answer: I do not understand this question. Fungi in the soil have many roles in breaking down organic matter and releasing elements in plant-available forms. Some fungal species are saprophytes which mean they live on dying and dead plant material; some will infect living plant material such as root pathogens causing the plant to become less thrifty and, maybe, die. Some may be mycorrhizal meaning that they have a special relationship with certain plant roots providing the roots with elements such as phosphorus, in exchange for carbohydrates.
The problems after wet weather suggests you are referring to leaf pathogens such as downy mildew or powdery mildew, for example. Mildews can be a problem in damp weather but are generally a sign of poor management and excess use of chemicals. Our system of monoculture increases the outbreaks of mildews in vineyards, for example. Improving soil health is a good start to minimising leaf pathogens. Managing the canopy of vines or fruit trees so that good ventilation occurs is a good strategy. Dry leaves minimise fungal spore germination so disease organisms cannot get established. Considering biological alternatives would be my suggestion. There is a biological to replace most chemicals. Concoct Agpath P/L for advice if you wish.

Q16. Organic horticultural production systems – benefits in the long term?

Answer: As temperatures rise and rainfall becomes less predictable and weather events generally become more unpredictable, then organic/biodynamic/biological production systems are the only ones that can guarantee longer-term food availability. These systems ‘farm’ the soil rather than ‘mine’ the soil, increase soil organic matter and hold more soil moisture allowing crops to be grown and harvested in years of drought where conventional farming systems cannot produce. Look at the 30 year research project into conventional and organic farming systems from Rodale Institute in Pennsylvania, USA on www.rodaleinstitute.org . Providing a healthy soil minimises disease, increases plant health and increases antioxidant and vitamin content of the resultant food. Look at using compost, mulch, compost teas, kelp and fish as soil and foliar applications. Look at Agpath P/L website for assistance.

Q17. What are the effects of herbicides on soil life?

Answer: Herbicides do affect the soil biota unnecessarily. Weeds should be looked at ‘mulch potential’ and mulched after mowing. Good soil does not allow weeds to grow as they need a bacterially dominated soil. Most cropping plants are perennial and benefit from a fungal dominated soil. Addition of compost and mulches to increase the organic matter in the soil will turn over the soil biota to fungal domination. It is better to farm the soil and build soil health than it is to apply chemicals. Growers using Glyphosate, a broad spectrum herbicide, are having great success in managing weedy species as they transition to biological systems, by adding humic acids to the herbicide in dilutions of 50% to 75% herbicide. The mix has less impact on the soil biota allowing it to recover much more quickly than straight herbicide alone.

Q18. What are the best management practices for my soil?

Answer: Consider a biological approach to your farming practices. Have your soil chemical and biology levels tested (see Agpath website for help) and then consider a programme to repair the soil. Improving the organic matter in the soil helps it to hold water and nutrients. Active soil biota release plant available nutrients so that external applications do not have to be made which affect the soil biota negatively. If amendments such as lime or potassium need to be added in the transition stage, then I they can be added to compost and broken down into plant available forms before they are applied to the soil or plants. As the soil develops and the plants are healthier, then external sources other than seaweeds, fish, rock dust, molasses, compost, compost teas will not be necessary.

 

Q20. I would like to be able to recognise and identify soil micro and meso fauna and flora and to familiarise myself with the local earthworm species.

Answer: Purchasing a small microscope – buy the best you can afford – with a digital camera and learn how to use it to look at bacteria, fungi, protozoa, nematodes, etc in the soil or compost. Amazon is a good place to look for cheaper scientific texts that help in identification. Buy books with lots of pictures. Contact Agpath or watch the Agpath website for classes in fungal identification or identification of microbes using a microscope. Join or start a local microscope group. Join the Agpath student restricted site.  www.agpath.com.au .

 

Q21. Want to know what effect herbicides have on soil organisms.

Answer: Answer: Herbicides do affect the soil biota unnecessarily. Weeds should be looked at ‘mulch
potential’ and mulched after mowing. Good soil does not allow weeds to grow as they need
a bacterially dominated soil. Most cropping plants are perennial and benefit from a fungal
dominated soil. Addition of compost and mulches to increase the organic matter in the soil
will turn over the soil biota to fungal domination. It is better to farm the soil and build soil
health than it is to apply chemicals. Growers using Glyphosate, a broad spectrum herbicide,
are having great success in managing weedy species as they transition to biological systems,
by adding humic acids to the herbicide in dilutions of 50% to 75% herbicide. The mix has less
impact on the soil biota allowing it to recover much more quickly than straight herbicide
alone

Q22. We want to improve our pastures and therefore get basic information on how to improve the quality of our soil.

Answer: Answer: The pathway to healthy soil starts with having a complete chemistry and biology
carried out on all the different soil types on the property. This data is considered along
with the previous history of the property such as fertiliser input, grazing or cropping
history; irrigation, flooding potential, etc. With all that information, a programme either
of continued chemical use or a change to biological farming, either totally or in part, can
then be designed. A commitment then to a management programme is implemented with a
consultant. Evidence is widely available to show that animals are happier and healthier in a
farming system that has minimal chemical input. Production can be higher and crop quality is
certainly higher. Having all the information necessary to make the change is what is needed
and that is available from consultants who work within the biological/organic system. I am
always available to explain the science or to help with a programme.

 

Q23. Can microbes affect phosphorus levels?

Answer: Answer: Different plant species have endo or ecto but very few have both. Some plant types
do not have mycorrhizae at all. Look at my website for lists of plants having different types of
mycorrhizae www.agpath.com.au. Cultivation or constant disturbance of the soil will deplete
the fungal population through constant breaking up of the fungal hyphal mat in the soil and
on organic matter. Adding salts such as super phosphate will badly affect fungi as will metals
such as copper often used for disease management.
The mycorrhizal fungi have the major role in harvesting phosphorus for plants in exchange
for carbohydrates for their energy source.

 

Q24. How to improve soil carbon?

Answer:Answer: See other Q&A addressing this topic (www.agpath.com.au/Information/FAQ).
Generally, less disturbance of the soil through ploughing or tilling; increasing organic matter with compost, compost tea and green crops such as lupins, broad beans, lucerne etc., and working them into the soil for nitrogen and organic matter. Pasture cropping so that the soil is never bare. Grow deep roots perennials to aerate the soil. Minimise or, better still, stop using chemical salts. Improve soil biology activity.

 

Q25. Successful composting regime….the process? And vermiculite?

Answer: Answer: The most comprehensive description of making thermal aerobic compost can
be obtained from DVDs by Dr Elaine Ingham (see farming Secrets website and catalogue
(www.farmingsecrets.com/store/caralogue). Vermiculite has thermal stability but is
biologically inert. It is used in commercial potting mixes, etc, but has no real use in a well
made aerobic compost that has a good mix of woody component, green material and
manures as the base materials.

 

Q26. Compost tea, composts, mycorrhizae, fungal/bacterial ratio?

Answer: Answer: I am not sure what this question is asking. Probably reading the answers to all the
other questions on the Agpath website will provide the information required. Mycorrhizae
are specialised fungi that have a mutualistic relationship with most living plants providing
the plants with phosphorus, for example, and receiving nutrients/carbohydrates in return.
Mycorrhizal fungi will not be found in composts because that is dead plant material. The
fungal strands/hyphae seen in good compost belong to saprophytic fungi which live on dead
and dying plant material.
Fungal/bacterial ratios in compost or soil depend on the plant system. Annual species tend to
have a bacterially dominated soil and perennial plants are fungal dominated by preference.

Q27. Bio-fertiliser… making and applying?

Answer: Answer: Bio-fertiliser is a catch-all name for any product that contains living microbes that
stimulates plant growth when applied to the soil around living plants. The product should
contain plant-growth-promoting-rhizobacteria (PGPR) and, hopefully, some fungi and algae.
There are commercial products available. The best are those made on site from your own
materials.
Commercial bio-reactors process plant material and waste from sewerage resulting in solid
reduced waste and methane that can be used as a power source.

 

Q28. How effective is compost tea and biodynamic 500 solutions to soil biology?

Answer:Answer: The most microbial activity is in the rhizosphere (area of soil immediately around
plant roots) where plant root exudates provide nutrients for the microbes and they, in turn,
supply nutrients from the soil the plant roots.
Soil type and soil pH are more likely to affect availability of important macro and micro
elements. Soil pH can be adjusted using good compost where the microbes will then function
to supply nutrients in plant available form.
An active and fully functioning soil food web is not present in poor soil so improving the soil
with compost and natural organic matter will allow the soil food web to function effectively
and provide nutrients needed by the plants resulting in healthy and productive plants
producing nutritious crops whether it is good quality grass for stock or tasty vegetables.

Compost tea contains a diverse population of microbes that stimulate the rhizosphere
populations of plants. Biodynamic 500 is a concentrated and diverse population of microbes
all of which have a role in plant and soil health particularly if made on one’s own property
from materials found on one’s property.
Commercial preparations are available but these are never as good as a well-made
preparation locally. Like compost teas, the microbes stimulate the populations in the soils
and lead to greater nutrient uptake into plants.

 

Q29. How will the CMA or community benefit from my participation? Eg what might I be able to do to my land after these workshops that I cannot do now?

Answer: Hopefully you have absorbed the information presented by experts in the field of soil health.
You will have met like-minded people all of whom are on the same journey as you who
are always glad to assist in relating their experiences so that you do not have to “reinvent
the wheel! “The Agpath website has papers, articles, and websites that will lead you to
more information. The workshops are designed to give you confidence that biological soil
health translates into human health and long term maintenance of our precious soil and
environment.

Q30. How can I reduce the use of chemicals and herbicides?

Answer: Answer: Consider a biological approach to your farming practices. Have your soil chemical
and biology levels tested (see Agpath website for help) and then consider a programme to
repair the soil. Improving the organic matter in the soil helps it to hold water and nutrients.
Active soil biota release plant available nutrients so that external applications do not have to
be made that affect the soil biota negatively. If amendments such as lime or potassium need
to be added in the transition stage, then they can be added to compost and broken down
into plant available forms before they are applied to the soil or plants. As the soil develops
and the plants are healthier, then external sources other than seaweeds, fish, rock dust,
molasses, compost, compost teas will not be necessary.

 

Q31. How to identify beneficial organisms from others?

Answer: Answer: Not easily. Generally, it can be said that a healthy soil containing diverse soil
microbial populations, has all the beneficial that are required. The organisms that may be
considered pests have a role in the diversity of life on Earth and are kept in balance within
the soil web so long as the soil is in balance with its environment. When a plant is attacked
by insects or disease-causing organisms, it is because an imbalance has arisen most likely in
the soil or from use of chemical herbicides or pesticides removing the beneficial. Laboratories
specialise in identification of pests and diseases and beneficial organisms. There is literature
available in libraries that will help to a certain level.

Q32. How do you change soil microbes in a pasture environment?

Answer: Answer: Consider a biological approach to your farming practices. Have your soil chemical
and biology levels tested (see Agpath website for help) and then consider a programme to
repair the soil. Improving the organic matter in the soil helps it to hold water and nutrients.
Active soil biota release plant available nutrients so that external applications do not have
to be made which affect the soil biota negatively. If amendments such as lime or potassium
need to be added in the transition stage, then I they can be added to compost and broken
down into plant available forms before they are applied to the soil or plants. As the soil
develops and the plants are healthier, then external sources other than seaweeds, fish, rock
dust, molasses, compost, compost teas will not be necessary.

Q33. Without soil water, can there be active and beneficial soil microbial life?

Answer: Answer: Even the driest of deserts support an active microbial population of specialised
microbes that have adapted to the harsh conditions. There is not a habitat on the planet that
is devoid of some form of microbial life. Those microbes have a relationship with the plant
life in the environment and balance is maintained for the benefit of all life. If we consider
what think of as ‘normal’ environmental conditions, eg climatic conditions with temperatures
between about 10 and 30oC, then normal soil biota do need moist but not wet soil for
maximum microbial activity.

Q34. I have native pasture with some introduced species. I am looking for what should be going on in the soil to produce healthy grasses.

Answer: Answer: Natives grasses have adapted to a nutritional deficient soil compared with
that required for cropping plants. Have a soil biology test carried out to see if there are
deficiencies in the soil food web. Then use fungal dominated composts and compost teas
to stimulate growth at the appropriate time of the year. Do not add chemicals or any
remediation in large amounts as the plants would not be able to deal with the high input
of nutrition. It is always better to apply regular amounts of required elements though good
compost or compost teas when it is needed such as before flowering. Introduced species
require more nutrition than native species but well-balanced soil microbiology will adapt to
accommodate all plant species in the pasture.

Q35. How to encourage desirable native grasses and discourage undesirable native species in improved native pastures.

Answer: Answer: It is more difficult to encourage one species over another if they are all the same
botanical group, in this case probably the Graminaceae. One suggestion is to improve the
soil fertility with addition of organics matter in the form of compost, compost teas, etc., and
encourage flowering and seeding of those species wanted. Depending on the distribution
of the unwanted species, heavy grazing may help with the immediate seeding of the grazed
down areas with the species of choice. To answer the question more appropriately, I would
need to know more about the property.

Q36. Long-term soil organic matter products for long-term carbon sequestration?

Answer: Answer: This has been answered in part in other questions. It is not a problem to add carbon
to the soil, but it is difficult to hold that carbon in the soil. Keeping a perennial plant cover on
the land is probably the most effect manner in holding carbon. Tilling/cultivation loses more
carbon from the soil because it damages the fungal component important in holding soil
structure; exposes soil to heat and UV that also damages soil biota and also allows elements
to return to the atmosphere. Pasture cropping is a method gaining popularity because the
pasture sward is kept intact while the crop is planted, grown and harvested maintaining the
fungal component’ Look at any work by Jeff Baldock as he is the recognised expert in the field
of carbon sequestration.

Q37. Are there any methodologies for measuring soil carbon?

Answer: Answer: Take a look at the Australian Government Department of Climate Change & Energy
Efficiency website. Here you will find the methodologies used in assessing farm carbon for
the Carbon Farming Initiative. This is a good website to read masses of information about
carbon mapping and other topics around carbon sequestration. The Garnaut Report is useful
to read. Read any papers by Jeff Baldock, CSIRO Land & Water/Sustainable Agriculture
Flagship. Jeff is the leading scientist in this field.

Q38. What changes occur in the soil biology following a grazing period?

Answer: Answer: Farm animals cause compaction. The depth of compaction is generally within the
surface 10-15cms.The extent of damage depends on many factors such as stocking rates;
length of time of grazing; weather conditions; soil type; quantity and quality of vegetation
cover; soil water content, to name a few. Animals should not be allowed to graze overly wet
pastures because they cause pugging holes which fill with water in the wet but dry to hard
dangerous uneven ground in the dry. Vegetation cover is lost and weedy species can intrude.
Good grazing practices would see healthy well established pastures grazed to no less than
10cms in rotations that allow the soil and pasture species to recover. The manure from the
animals helps to fertilise the soil providing nutrients for soil biota. These nutrients, as they
are made plant available by microbes, provide a stimulus in plant growth.

Q39. Relationship between microbial types and plant pasture production?

Answer: Answer: Healthy perennial pasture has a diverse population of all the necessary microbes
for healthy plant production. Perennial systems have well developed mycorrhizal fungi
populations that maintain good soil structure, assist in water holding and carbon
sequestration. Cultivation destroys the fungal component of soil regardless of the
composition of sand, silt or clay. Minimal disturbance of he soil maintains the diverse soil
microbes.
Mixed plant species in the pasture, rotational grazing leaving no less than 10cms of grass
cover, maintaining good ground cover to minimise weedy species, addition of good compost
or compost tea, and feeding with fish and seaweeds will maximise the soil microbial
populations and result in healthy pasture and grazing stock.

Q40. How do chemical and conventional fertilisers affect the soil food web?

Answer: Answer: Any salts adding in large amounts will damage soil microbes to a greater or lesser
extent. Metals such as copper will affect all fungi and phosphates have a negative effect on
mycorrhizal fungi in particular. Mycorrhizal fungi have a role in the soil of scavenging for
phosphates and supplying them directly in plant available form to plant roots in exchange for
carbohydrates which fungi cannot manufacture because they are non- photosynthetic. Any
disruption to this symbiotic relationship causes loss of mycorrhizal fungi leading to loss of
soil structure and loss of water holding capacity. Look at literature in the journal ‘Acre’, J. of
Soil Microbiology, and others, for peer reviewed papers. If you add 10% of the recommended
rates of NPK to good compost and then distribute the amended compost or compost tea to
your soil, you will improve the soil without damaging the soil microbes.

Q41. Impact of soil biology on soil carbon and measuring carbon over time?

Answer: Answer: This question has been answered in other questions.

Q43. Microbe activity in root zone – want to understand more.

Answer: Answer: The region around the root zone of healthy plants known as the rhizosphere is the
most microbial active, rich and diverse area in the soil. There is much literature on this topic
and cannot be condensed to a few lines. Plant exudates are concentrated in this region and
signalling between plant roots and microbes actively translocate nutrients from soil microbes
to the roots and, in the case of mycorrhizal fungi, from roots to the fungi. Soil biology is a
term using to describe all the organisms in a good soil. In the chart below you will see the
many levels and interactions that occur naturally in a fully functioning soil food web. It is
getting these all functioning providing healthy plants with the nutrients they need that is our
philosophy in biological farming. Minimising or removing commercial chemicals from the
soil management programme is a good start. Adding amendments to good aerobic thermal
compost is a better way of adding chemicals to the soil. Learn to use a simple microscope
and use it as often as possible looking at soils, composts, compost teas, etc. Take electronic
pictures and email to someone like me, Mary, at agpath@dcsi.net.au and I will give you
identification. You can look for books to buy or use the websites through Google or any
other search engine. There are great pictures, videos, etc on- line for you to search on your
own. Another service Agpath offers is the closed part of the website where people who have
participated in workshop s can join and submit their pictures but also have access to all the
other pictures people have sent in and I have written an explanation of the content.

Q44. Effect of phosphorus application on microbes?

Answer: Answer: Any salts adding in large amounts will damage soil microbes to a greater or lesser
extent. Metals such as copper will affect all fungi and phosphates have a negative effect on
mycorrhizal fungi in particular. Mycorrhizal fungi have a role in the soil of scavenging for
phosphates and supplying them directly in plant available form to plant roots in exchange for
carbohydrates which fungi cannot manufacture because they are non- photosynthetic. Any
disruption to this symbiotic relationship causes loss of mycorrhizal fungi leading to loss of soil
structure and loss of water holding capacity. Look at literature in the journal ‘Acre’, J. of Soil
Microbiology, and others, for peer reviewed papers.

 

Q45. Response time for soil biology to bounce back after disturbance/bad practices/drought?

Answer: Answer: Response time for recovery of soil biology depends largely on the population of soil
microbes before the adverse conditions impacted on the soil. A soil that been misused, such
as use of chemical salts as fertiliser, herbicides, over cultivation or over grazing in the case
of pastures, compaction through trafficking or too many animals, will leave the depleted of
diverse soil microbes and recovery will be slow if ever under that system.
In contrast, a soil that has been treated biologically will have a diverse soil microbial
population, good grass cover with diverse species, few if any weedy species, good water
holding capacity because of the higher organic matter in and on the soil and little or no
compaction. The large and diverse soil microbial population will come back very quickly after
an adverse event because it is returning from a high base.

Q46. The way different soil types respond/react to soil biology in the short and long term.

Answer: Answer: Soils are made up of different proportions of sand, silt and clay. Light soils that have
higher proportions of sand are more difficult to have hold organic matter and carbon and
nutrients, generally, and require much more input to turn them into productive sandy loam
types with nutritional value.
Loamy soils are easier to work and hold organic matter much more readily than the sands.
High clay content soils can have problems with water logging as can any soil that is misused
and compacted. Draining heavy soils may be necessary for them to be productive.
Most soils can be recovered in a reasonably short time frame. It is simply that some take
more effort than others.
Once the organic matter builds up and earthworms move air and water deeper into the
soil profile, then the diverse populations of soil microbes will actively increase nutritional
opportunities for plant species.

Q47. How do you improve/increase your quality and quantity of soil microbes present?

Answer: Answer: As temperatures rise and rainfall becomes less predictable and weather events
generally become more unpredictable, then organic/biodynamic/biological production
systems are the only ones that can guarantee longer-term food availability. These
systems ‘farm’ the soil rather than ‘mine’ the soil, increase soil organic matter and hold
more soil moisture allowing crops to be grown and harvested in years of drought where
conventional farming systems cannot produce. Look at the 30 year research project into
conventional and organic farming systems from Rodale Institute in Pennsylvania, USA on
www.rodaleinstitute.org. Providing a healthy soil minimises disease, increases plant health
and increases antioxidant and vitamin content of the resultant food. Look at using compost,
mulch, compost teas, kelp and fish as soil and foliar applications. Look at Agpath P/L website
for assistance.

Q48. Measuring the effectiveness (or otherwise) of deep ripping to improve soil microbiology.

Answer: Answer: Any sort of cultivation has an effect on soil microbiology in particular fungal species.
If a piece of land has to be recovered from a poor condition, then an initial ripping may be
the only way to begin the process of improving the soil. This is a once only event. From there
on, the only disturbance should be with something like a yeoman’s plough. Organic matter
can be added in several ways; planting green manure crops or a deep rooted perennial
such as lucerne. Consider pasture cropping so that the mycorrhizal fungal population that
establishes in a perennial system is disturbed as little as possible. It is the mycorrhizal fungi
that help to maintain good soil structure and water holding capacity. Mycorrhizal fungi
produce an exudate called Glomalin that is now known to hold far more carbon than do
the humates. So, in terms of carbon sequestration, maintaining a good population of fungi,
particularly mycorrhizal fungi, in the soil by minimal disturbance, has long term benefits for
plant, soil and environmental health.