- The City beneath the surface of the Earth
In the Sept 24 edition of the Sydney Morning Herald columnist Elizabeth Farrelly quotes research undertaken by Canadian Forest Ecologist Professor Suzanne Simard. Simard spent 30 years proving that trees exchange information, nutrition, genetic material and hormones. According to Simard as reported by Farrelly when trees are shaded, others – often different species – feed it carbon, nitrogen and phosphorus via a vast underground internet of roots and mycorrhizal fungi.
If you would like to listen to this story then click on the following link. It is truly a fascinating one that has been expertly captured in the interview: http://www.radiolab.org/story/from-tree-to-shining-tree/
- Fertiliser trial by the DPI
Making sense of what fertilisers are best for a given condition is never a simple quest. There are so many variables involved such as soil type, soil structure, aeration and soil biological life. The following three stories are an illustration of this point.
The first story is based on an extensive research program conducted by NSW DPI. The results in the following story are for 3 years up until 2012. Here is the link:
Second Story: Our next story takes a different slant again and begins the process of questioning whether applying fertilisers do more hard than good. The research is from Western Australian and is current. The story questions whether fertilisers simply set up a soil input addictive system. Read on:
A microbial soil test undertaken by Microbiology Laboratories Australia (Microbe Labs) for a leading research project near Cranbrook WA, by the Gillamii Centre, has produced results with astounding implications for soil health in cropping systems.
A range of parameters were tested earlier this year by Microbe Labs, on soil samples collected from five different cropping systems within the Great Southern region, to determine the amount of soil phosphorus (P) available to plants through typical soil microbiological processes for each. Twenty units of fertiliser P was then added to the soil which was left to incubate and retested to determine how much of the total soil P and fertiliser P became available to the plant, and ultimately, how much was locked up.
The findings indicated there is insufficient soil biological activity to prevent the vast majority of the applied P being quickly locked up in a ‘non-plant available’ form – mostly likely to be due to binding with aluminium and iron in the soil A similar result occurred last year when testing for nitrogen fixing bacteria, showed there was very little activity of the free living nitrogen fixing bacteria – which are known to be suppressed when fertiliser synthetic nitrogen (N) is applied over threshold levels – and negatively impacts the carbon to nitrogen ratio at a time when we desperately need to be building soil carbon levels because soil organic carbon is like a sponge that holds nutrients, water and air.
Microbe Labs head microbiologist, Ash Martin, said it is the first time he has seen replicated trials like this and there is a lot to be learnt. “The message we are getting is that inefficient use of the N and P is creating an addictive system – the more you put on, the more you have to put on and the more it suppresses the natural processes that facilitate fertiliser availability, while also making the soil more acidic.”
Project Manager, Wendy Bradshaw with Specialist Advisor, Ken Bailey said the project aims to look for efficiencies that can result in minimizing inputs and maximising production – as would be expected in a healthy soil. They are also looking at biological systems and nitrogen fixing within biological systems. It is our understanding that a healthy soil is one that is fixing lots of N. Ongoing trial work is needed to better understand the complexities of how to transition from a fully synthetic fertiliser input system to one that combines the best of the synthetic and biological inputs to meet the needs of biological processes that feed the plant while improving soil health.”
The three year project ‘Investigating links between soil health and innovative cropping systems’ is driven by the Gillamii Centre (a not-for-profit grower group focused on Sustainable Agriculture) as a result of philanthropic funding from Mt Barker Chicken. The project involves measuring key physical, biological and chemical soil heath indicators (and emerging patterns) over time. Relationships between key soil health indicators, N and P inputs and yield have been analysed from the first year’s data by the University of Western Australia to provide insight into productivity of the five variations of biological and conventional broad-acre cropping systems being studied.
The next step is to continue testing and analysing results relative to the different cropping systems to see if the problem can be better defined and determine what can be added or implemented to improve it. “I hope that we can continue to build on this work as there is so much that isn’t understood in biological cropping and lots of exciting opportunities to explore. For example, at a summer cropping site near Lake Grace last summer on average soils resulted in a doubling of soil microbial activity compared to better soils where the summer weeds were sprayed out.
A prominent argument for intensive use of farm chemicals is the need to feed a world population that is growing by the second (http://www.worldometers.info/world-population/
However, a contrary set of arguments are presented by Guardian journalist Felicity Lawrence. To read more go to: https://www.theguardian.com/commentisfree/2016/oct/02/agrichemicals-intensive-farming-food-production-biodiversity?CMP=Share_iOSApp_Other