This is a case study produced by Soil Foodweb Australia.
Soil Foodweb increases banana production:
Includes a photographic timeline
Sustainable Banana Plantation, Korora (near Coffs Harbour), New South Wales.
The Taylor family has been growing bananas in the Coffs Harbour region (mid north coast of NSW) for more than seventy years. While the early years used organic methods, inorganic chemicals soon flooded the market and were widely used, initially with excellent results. However, the limitations of conventional methods were soon realised as increasing amounts of chemicals were needed as soil health declined. Production costs were increasing while yields were decreasing and with the strong competition from the North Queensland banana industry, the Taylor family plantation decided to convert to an organic system. The price incentives for organic produce were also an attractive proposition.
However, the problems that the Sustainable Banana Plantation encountered during this period of conversion proved to be an important lesson for anyone considering moving towards a more sustainable system. This experience highlights the importance of having a healthy soil foodweb and its role in nutrient retention and availability, disease suppression, and improved soil structure with increased water-holding capacity.
Initial attempts to move towards a more sustainable approach involved the drastic reduction of chemical use and a reliance on nitrogen-fixing plants between rows. “We thought all we needed to do was to grow nitrogen-fixing crops and this would replace the nitrogen that used to be available through using chemical fertilisers,” said Graham Taylor, owner of the Sustainable Banana Plantation. However, by 2001 the results were disastrous with widespread stunting, yellowing leaves, minimal suckering and the proliferation of weevil borer.
It was around this time that the Soil Foodweb Institute hosted a seminar in the Coffs Harbour region with Dr Elaine Ingham. It was here that Mr Taylor realised the importance of soil micro-organisms and in 2002 the Sustainable Banana Plantation incorporated Soil Foodweb techniques.
The first step was to address the compaction issues and inoculate the soil with the right microbes. For banana the desired fungal to bacteria ratio is around 2-5:1. At the Sustainable Banana Plantation this meant a turnaround from a bacterial dominated soil that was encouraged by years of inorganic chemical use and poor soil structure. Therefore, a high quality fungal dominated compost and/or compost tea had to be applied. The Sustainable Banana Plantation used both compost and compost tea in addition to organism foods during the establishment phase. Compost was applied around the base of the plants while compost tea, made from high quality thermal compost, was applied as a soil drench and foliar spray. With the use of compost and compost tea to re-introduce a huge diversity of organisms the Sustainable Banana Plantation has had considerable success and negated potential ruin from earlier attempts at sustainable farming methods.
The Sustainable Banana Plantation does not use any inorganic chemicals and has been certified organic since March 2003. This means they have been able to fetch prices around $21 per carton compared to the $8-$9 for conventional cartons of NSW bananas (in average years).
The management of the soil foodweb and inoculation of beneficial organisms including fungi, bacteria, protozoa, and beneficial nematodes has significantly increased disease suppression, increased nutrient retention and availability, and improved soil structure. “There has been a significant increase in size of the banana plants and increased number of leaves, which are now dark green in colour, with lots of suckers. Micro and macro biology is returning to the soil including earth worms and green frogs and the soil now has visible structure teaming with life including visible evidence of fungi. There has also been an increase in the size and weight of the bunches,” said Mr Taylor of the results that have been recorded since the Soil Foodweb approach has been adopted.
The improved soil structure has reduced water usage on the property by around twenty percent. There has also been the development of much longer, healthier root systems and an increase in beneficial nematodes. The more vigorous root systems are an important aspect, especially in the sub-tropical areas where ‘rootless bananas’ have been a persistent problem over the last twenty-five years.
The natural biology combined with the application of compost teas has also controlled disease outbreaks at the plantation. “There is little evidence of the typical fruit diseases and now we have a balanced biology in the plantation we do not see the typical boom and bust cycles of diseases on the fruit,” Mr Taylor said. “All that was necessary was to introduce the right type of microbes and then keep them active by giving them the appropriate foods, water and aeration.”
A Photographic Timeline
Organic sub-tropical bananas: Conversion from conventional system without reintroducing beneficial organisms. Severe stunting of plants, nutrient deficiencies and minimal suckering.
Before Soil Foodweb Approach: Poor bunch development
Before Soil Foodweb Approach: “Rootless banana” a major issue.
The microbiological Soil Foodweb Approach Applied
Applying high quality compost around base of plants.
Compost tea brew – High quality compost used (i.e. contains adequate
beneficial fungi, bacteria, protozoa, and nematodes).
Foliar compost tea application.
Foliar compost tea application.
Compost tea applied as a soil drench.
Soil Foodweb Approach: Visible fungal activity.
Soil Foodweb Approach: Now throwing larger bunches.
Soil Foodweb Approach
Soil Foodweb Approach: Longer, healthier root systems.
Soil Foodweb Approach.