A Backyard Vineyard Experiment in Turning Waste Into Soil
If you keep a Sulcata tortoise and grow grapevines, you may have an overlooked source of organic material sitting right in your backyard: tortoise manure.
I raise a Sulcata tortoise and, from first-hand experience, have been using its feces as an ingredient for creating organic fertilizer for my backyard growing areas. That experience led me to look more closely at how Sulcata manure can fit into a vineyard soil-management program.
Why Sulcata Manure Is Interesting
Sulcata tortoises are herbivores whose diets consist primarily of grasses, weeds, leaves and other fibrous plant material. Their manure therefore contains partially digested plant matter that can be returned to the soil as organic material.
Rather than thinking of tortoise manure as a concentrated fertilizer, it is better viewed as a soil-building amendment.
When incorporated into a composting system, it can contribute organic matter and nutrients while the finished compost can help improve soil structure, moisture retention and biological activity.
Compost It First
My preferred approach is not simply to pile fresh tortoise feces around grapevines.
Instead, Sulcata manure can be combined with other compostable backyard materials such as:
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Dry grape leaves
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Grapevine prunings that have been chopped or shredded
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Grass and weeds
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Fallen leaves
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Shredded untreated cardboard
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Other suitable plant material
Allowing these materials to compost together produces a more stable amendment that can eventually be returned to the vineyard.
Composting is also an important safety consideration. Reptiles can carry Salmonella and other microorganisms, so fresh tortoise feces should be handled carefully. Wash your hands after handling it, keep it away from food-preparation areas, and favor properly composted material rather than applying fresh feces around edible crops.
How I Use the Finished Material
Once properly composted, the finished material can be spread across the soil around established grapevines while keeping it away from direct contact with the trunks.
A modest layer of approximately ½ to 1 inch can be used as part of an overall soil-building program and covered with mulch where appropriate.
The objective isn't to force rapid vine growth. It is to gradually return organic material to the soil and create a healthier growing environment.
Don't Confuse Compost With Correcting a Deficiency
There is an important distinction.
Sulcata manure compost can contribute nutrients, but its exact nutrient composition will vary considerably depending on the tortoise's diet, bedding and composting materials. It should not be treated as a known N-P-K fertilizer.
If a soil test identifies a significant phosphorus, potassium, nitrogen or micronutrient deficiency, address that deficiency according to the soil-test results rather than assuming tortoise manure will correct it.
Think of the compost as the long-term soil-building component of your vineyard program and targeted fertilizer applications as tools for correcting specific deficiencies.
From Tortoise to Grapevine: Closing the Backyard Nutrient Loop
This is what I find most interesting about the process.
Grass and vegetation feed the Sulcata. The tortoise produces manure. That manure is composted with vineyard and yard waste. The finished compost goes back into the soil supporting the grapevines.
Vegetation → Sulcata → Manure → Compost → Vineyard Soil → Grapevines
It's a simple example of recycling nutrients that would otherwise become waste—and another way a small backyard vineyard can move toward a more regenerative approach to soil management.
This article describes personal gardening experience and general educational information. Compost characteristics vary, and soil testing should guide specific nutrient applications.