Think Twice About Spreading Manure on Your Garden
During my tenure as your Agricultural Extension Agent, I have observed five gardens in Chouteau County where gardens produced no vegetables. Plants that did emerge were stunted and did not produce. The cause of these devastated gardens is usually one of two things. Either pesticide contaminated manure has been applied to the garden, or too much manure has been added to the garden.
One issue that can result from a manure application is pesticide contamination. Do not use manure from animals that have grazed forage or pastures treated with high-risk growth regulator herbicides like Milestone. The half life in the soil of milestone can range from five to 533 days.
Homeowners have a few options if contaminated soil is evident in their gardens.
• Create another
vegetable garden in a different location until the contaminated garden passes toxicity tests in subsequent seasons.
• Incorporate one-pound activated charcoal per one gallon of water for each 150 square feet into the top six inches of contaminated soil. The activated charcoal should adsorb some of the pesticide and decrease toxicity towards non-target plants.
• Remove soil and replace with clean soil. This may be less costly if homeowners have smaller gardens.
Adding too much manure can also result in stunted garden plants. Adding the manure causes a nutrient imbalance because manure has variable levels of Nitrogen, Phosphorus and Potassium. Manure often has more nutrients than plants need. Manure can also have high soluble salts which can cause nutrient imbalance and water stress. The solution for over application of manure is to blend manure with regular soil depending on soil test results.
Weed spread can also be an issue associated with manure. If you would like to minimize weeds in your garden, use chicken manure. Chickens are really good at breaking down weed seeds in their manure unlike other livestock like cattle, sheep, goats hogs and horses.
Information from this article came from Montguide MT201008AG (Minimizing Pesticides and Contaminated Soil Around the Garden). For further gardening information, a complete set of gardening Montguides is available at the Chouteau County Extension Office. The office is located in the green building behind the courthouse.
Montana State University, U.S. Department of Agriculture and Montana Counties Cooperating. MSU Extension is an equal opportunity/affirmative action provider of educational outreach.
