Commercial VCL?

Upon some final research, Jess has come across the nutrisoil website, that promotes the use of VCL.

Check it out here:
http://www.nutrisoil.com.au/

This page outlines the benefits that farmers have seen from using this VCL. Definitely worth a look!
http://www.nutrisoil.com.au/farmers/

SO, where from here?

Wormfarming is an effective waste management technique, in addition to being a good quality organic fertiliser. 

From our project, we suggest that VCL be utilised as part of organic farming practices, and, although it may have strong commercial potential, further study is most certainly required. Such further study would investigate factors such as any nutrient deficiencies that standard VCL may have in its ability to support plant growth, large scale methods of production and preservation of Organic Matter, and also its potential to supplement with synthetic NPK fertiliser.

The results of our study!

After the last couple of months working on our project, here is a brief overview of our results, compiled by Georgia. More comprehensive results to be posted soon!

Did VCL support plant growth?

YES!

Treatment with VCL increased stem and leaf development as well as root development for both soybean and lettuce plants. It resulted in increased plant height of the lettuce but did not increase the plant height of soybeans.  

 

How effective was VCL?

VCL was significantly more effective in supporting plant growth than the controls, however it was less effective than treatment with Aquasol

 

Are the benefits of VCL due to its chemical composition or its microbial activity?

Both autoclaved leachate and normal leachate resulted in similar plant growth. This means that the study found the benefits of VCL are primarily due to its chemical composition, rather than microbial activity.

 

This is a surprising result as microbial activity is known to be crucial in supporting plant growth. Possible explanations why our experiment did not demonstrate this is as we used sand as the growth medium, its poor structure and lack of biological activity may not have provided an environment that would benefit from microbial activity. Also, the short timeframe of our study may have not been sufficient to demonstrate a significant benefit of microbial activity for plant growth.

 

Was there any differences between plants treated with the normal leachate and the autoclaved leachate?

Plants treated with the autoclaved leachate resulted in slightly greater above ground weights than the normal leachate. This may have occurred because sterilisation can increase the bioavailability of micronutrients and hence increase plant growth.

 

Also, plants treated with normal leachate resulted in a greater total fresh weight than plants treated with autoclaved leachate. This indicates that microbial activity may support plant growth that has better water uptake and water holding capacity.

Quick survey!

Hey guys,

If you have a spare minute, it would be great if you'd be able to fill out our super-brief survey:
http://www.surveymonkey.com/s/DJZP6Z8

It will literally take you less than one minute, and will help us out enormously!

Thanks everyone!

Pot trial results processing! 2 weeks till due date

This morning, Jono, Georgia and Polly met at the poly house, as the end of the pot trial had finally arrived! 

Gathering results involved counting the number of leaves on each plant, measurement of plant heights, then the removal of sand from all pots. After this step, photos were taken for comparative purposes, then above/below ground mass measured. 

Later in the day, dry weights were measured. 

Below are some photos from the day. More will be posted when results are interpreted.

Final result of the 40 pots

Lettuces

Soybeans

FAQs - The basic science

Recently, when we have been telling people about our project, we have been getting the same responses back. Therefore, Georgia kindly compiled the following:

1. What is vermicomposting and vermicompost leachate?

Vermicomposting, also known as wormfarming, is a waste management technique using worms to transform organic waste into biologically-rich manure (Carlos et al, 2008). Vermicompost leachate (VCL), or ‘worm tea’, is the liquid released by earthworms (Kandari et al, 2011). VCL is said to stimulate plant nutrient uptake and support plant development due to the humic acids, fluvic acids and plant growth regulators it contains. (Carlos et al, 2008).

2. What is the aim of your experiment?

Our experiment aims to determine if VCL is more effective fertiliser compared to an inorganic equivalent, which, in our case, is Aquasol.  

3. Why are you using aquasol?

We chose to use aquasol as it is a common purely synthetic fertiliser, which means it has no biological component. Other common commercial fertilisers such as Seasol and Nitrosol were not chosen, as they are organically based (from seaweed extract and blood and bone respectively) have growth promoters added (Zodape, 2001). 

4. Why are you growing lettuce and soybean plants?

As nitrogen is the key element in most fertilisers, we chose test the effectiveness of VCL and Aquasol on a nitrogen fixing plant (soybean) as well as a non-nitrogen fixer (lettuce) that is common in urban gardens. These plants were also chosen due to their rapid growth to suit our study’s limited timeframe.

5. Why are you growing the plants in sand?

Soil structure has a great affect on plant growth as it influences the movement of water, air and nutrients to plants (Charman and Murphey, 1992). As we did not want any differences in soil structure between pots, sand is being used, as it has very low inherit biological activity, and little to no structure.

6. What is the difference between normal leachate and autoclaved leachate?

As vermicomposting is an organic process, VCL contains both a biological component (micro-organisms) and a chemical component. Autoclaving is a process of sterilising, or killing the biological component that would be present. By comparing plants grown with normal leachate and autoclaved leachate, this will show us if VCL’s fertilising ability is due to its inherit biological activity, or if it is the chemical composition alone, that makes it a viable fertiliser.

7. Why are some of the plants being only given water?

As with any scientific investigation, there are control plants being grown, that are only receiving water daily. These plants will show the growth of plants in absence of fertiliser. 

If you have any more questions, please keep them coming!

Watering the lettuces last saturday

References

• Carlos, G, Dendooven, L, Antonio, G, 2008, Vermicomposting leachate (worm tea) as liquid fertiliser for maize (Zea mays L.), Academic Journals Inc, USA.
• Kandari, L, Kulkarni, M, Staden, J, 2011, Vermicompost leachate improves seedling emergence and vigour of aged seeds of commercially grown Eucalyptus species, Southern Forest: Journal of Forest Science, vol 77, 2, 534-535.
• Zodape, S, 2001, ‘Seaweeds as a biofertiliser’, Journal of Scientific & Industrial Research Volume, vol. 60, 5, 378-382.
• Charman, P, Murphey, B, 1992, Soils their properties and management. Soil Conservation Commission of NSW. Sydney University Press. Chapter 16. Soils and farming practice. Harte, A.J.

Day 16 of pot trial!

After some problems with our time lapse camera during the week, Jono has made a new structure that is less likely to fall, and re-started the camera yesterday (Wednesday) when he watered the plants.

Some photos from today are below. I was pretty excited to see that some differences are beginning to occur between treatments. I was surprised to see that the lettuces being fed aquasol look far healthier than those under leachate, autoclaved leachate or control treatments. Alternatively, in the soybeans, the leachate treated pots are looking far healthier. Time will tell!

Camera set up

Pot 6: Aquasol soybeans

Pot 16: Leachate soybeans

Pot 28: Aquasol lettuce

Pot 29: Aquasol Lettuce

So much growth! :D