Permaculture practice: Compost “banana circle”
The banana circle (organic decomposition pit) is a sustainable agricultural design commonly used in tropical regions to manage organic waste, enhance food production, and optimize water use.

Structure
The banana circle consists of a round pit, approximately 1 meter in diameter, surrounded by a raised soil mound. Banana plants are interspersed with other fibrous-root crops such as sweet potatoes, lemongrass, cassava, and taro to create a mutually supportive ecosystem.
How to Create a Banana Circle
Step 1: Selecting a Suitable Location
Choose a flat area with adequate space that is conveniently located for connecting wastewater pipes from the kitchen sink to the banana circle.
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Step 2: Digging the Pit and Installing the Wastewater Pipe
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Dig a circular pit about 1 meter wide and 80 cm deep.
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Use the excavated soil to form a 20 cm-high mound around the pit.
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Install a wastewater pipe leading from the kitchen sink into the pit.
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Step 3: Planting Trees
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Evenly plant banana shoots along the raised mound.
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Intercrop with fibrous-root plants suitable for the local climate, such as cassava and lemongrass.
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Use ground-cover plants like sweet potatoes to enhance biodiversity and improve soil resilience.

Photo source: Internet
Functions of the Banana Circle
The banana circle enables a continuous cycle of organic material, including household organic waste, decomposed leaves, and wastewater free from chemicals. It serves the following key roles:
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1. Organic Recycling
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The pit collects kitchen scraps, wastewater, and other organic materials.
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These materials decompose and supply essential nutrients to banana plants and companion crops.
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2. Moisture Retention
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The pit collects rainwater and wastewater, maintaining a moist environment ideal for banana plants, which thrive in wet conditions.
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3. Soil Fertility Enhancement
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Decomposed organic matter enriches the soil, creating a nutrient-rich environment that promotes healthy plant growth.
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4. Pest Control and Mulching
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The decomposed organic layer helps suppress weeds, retain moisture, and reduce pest infestations.
Maintaining and Caring for the Banana Circle
1.Regularly Add Organic Material
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Continuously supply the pit with organic waste to sustain nutrient cycling.
2.Banana Plant Maintenance
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Maintain only two mother plants and one sucker per clump to prevent overcrowding.
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Prune and harvest intercrop plants to maintain system balance.
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Weed regularly to prevent overgrowth around the pit.
3.Protecting the Wastewater Source
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Avoid using harsh chemical detergents.
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Prefer organic cleaning agents to ensure a safe and sustainable system.
By implementing and maintaining a banana circle, households can effectively manage organic waste, improve soil fertility, conserve water, and enhance food production, all while contributing to a sustainable and resilient agricultural system.

Adaptation in Tourist Accommodations
in Coastal Areas
The banana circle model is highly suitable for homestays and small eco-lodges with a maximum capacity of 20 guests or fewer.
To ensure efficiency and hygiene, banana circles should be positioned away from the kitchen to minimize flies and mosquitoes, preferably in garden areas for easy maintenance. The pit should be dug at a lower elevation than the kitchen to facilitate natural wastewater drainage.
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For accommodations with professional dining services, it is essential to install an appropriately sized grease trap to prevent excessive grease buildup, which may hinder organic decomposition.
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In coastal regions like Tam Thanh, where beachfront properties are common, an additional sand separation pitshould be installed to prevent sand accumulation from interfering with the decomposition process or burying the banana circle.