How safe is your backyard soil?

Checking soil health prior to free ranging your backyard poultry will eliminate the possibility of egg toxicity.

The benefits of growing our own nutritious, healthy food organically in the backyard vegie patch are well documented. But have you ever considered how healthy your garden soil is – and the flow on effect to your produce?

Waste and chemicals that pollute our air, soil and water can persist in the environment. Most chemicals enter our environment through sewage, waste, accidental discharge, or they might be by-products from industrial activity. Historical contamination sources, like lead paint and leaded gasoline have also impacted urban soil quality. Contamination can affect soil health and impact how our vegies grow. It may also have human health implications from eating garden produce or working in the garden if contaminants are present at high concentrations.

Soil, lead and backyard chooks

As well as impacting the fruit and vegetables that we grow and consume, soil contamination may also have ramifications in the keeping of domestic chickens for egg production. A favoured hobby of many Australians, research confirms over 400,000 Australians practise this form of urban agriculture (Chicken Guard, 2019). Particularly important to poultry enthusiasts in the inner suburbs of the major cities, egg toxicity is a potential risk for chickens (and humans) exposed to soil containing high levels of lead.

Research that we undertook at the Environmental Protection Authority (EPA) last year shows four factors pointing to possible lead contamination risks at levels that can affect your chooks and their eggs:

• Older houses
• Inner city areas with past use of lead-based paint and leaded petrol
• Timber construction
• Houses painted on the outside

If you are keeping chooks in the inner city, it’s best to have a dedicated chicken run where you can control soil quality and introduce sensible practical measures to mitigate exposure and ingestion. Testing your soil before you start is recommended.

GardenSafe

A new citizen science program by the EPA in Victoria, GardenSafe, aims to find out exactly how healthy our backyard soils are. EPA Victoria is offering high-tech help for Victorian gardeners, with free garden soil screening for trace elements and soil quality indicators, including soil texture, composition, nutrients and organic carbon.

GardenSafe is part of a global initiative that helps gardeners to investigate soil health and potential contaminants to make the most of their fruit and vegetable gardening, as well as chicken keeping at home. Participants in the program receive a free report from EPA’s Citizen Science team on their results. As a science-based regulator, EPA Victoria will use the findings from GardenSafe to build an understanding of contamination in residential gardens across Victoria.

The results will help gardeners to understand what’s in their soil and take action to reduce potential risk and exposure if contamination is present.

How to get involved

GardenSafe invites Victorians to send three garden soil samples for screening to assess samples for:

• Garden soil quality indicators, including soil composition, organic carbon, phosphorus and potassium
• Trace elements, including lead, arsenic and chromium

Soil samples must be from a residential property. EPA scientists will analyse the samples and send you a free report on the results. GardenSafe data will not be used for EPA compliance or enforcement activities.

Learn more about GardenSafe.

Written by Professor Mark Patrick Taylor, EPA Victoria’s Chief Environmental Scientist.