Enriching Soil with Manure: A Guide to Proper Application

Manure, a natural byproduct of animal husbandry, holds immense value as a soil amendment. Its nutrient-rich composition and organic matter content make it an effective soil enhancer, contributing to improved soil structure, water retention, and nutrient availability for plant growth. This article delves into the proper methods of manure application, considering various factors such as manure type, composting techniques, nutrient availability, and safety precautions.

Key Facts

  1. Manure is a valuable soil amendment: Animal manure supplies primary nutrients like nitrogen, phosphorus, and potassium, as well as micronutrients, to the soil. It also serves as a source of organic matter, which improves soil structure, water holding capacity, and drainage.
  2. Types of manure: Manure used as fertilizer typically comes from herbivores such as cows, sheep, and chickens. It is important to avoid using cat, dog, or pig manure in vegetable gardens or compost piles.
  3. Fresh manure: Fresh manure, especially poultry manure, is high in ammonia and soluble nitrogen. It should be incorporated into the soil within 12 hours of application to prevent nitrogen loss as ammonia. Fresh horse manure may contain lots of weed seeds, so it’s important to be cautious when using it. Fresh manure should not be used on vegetables, particularly root crops, due to the potential transmission of human pathogens.
  4. Composted manure: Composting manure eliminates some of the problems associated with fresh manure, such as odor and weed seeds. Composted manure has lower nitrogen availability but contributes more to the organic matter content of the soil. It is not as critical to immediately incorporate composted manure into the soil, but it is still recommended to do so for maximum benefit.
  5. Nutrient availability: The nutrient content of manure varies depending on factors such as the type of animal and its bedding. Generally, 70-80% of phosphorus and 80-90% of potassium will be available in the first year after application. Nitrogen availability is more complex and depends on microbial activity. Recommended application rates for fresh manure or compost are provided based on the desired nitrogen supply.
  6. Safety considerations: Non-composted manure can contain harmful bacteria that may contaminate vegetables and cause human disease. Proper composting is necessary to kill these bacteria. USDA National Organic Program rules specify the minimum interval between non-composted manure application and vegetable harvest to minimize the risk of bacterial contamination.

Types of Manure and Their Characteristics

Manure used as fertilizer primarily originates from herbivorous animals like cows, sheep, and chickens. Each type of manure possesses unique characteristics that influence its application and effectiveness.

Fresh Manure

  • Fresh manure, particularly poultry manure, is characterized by high levels of ammonia and soluble nitrogen.
  • To prevent nitrogen loss as ammonia, it should be incorporated into the soil within 12 hours of application.
  • Fresh horse manure may contain numerous weed seeds, necessitating caution during usage.
  • Due to the potential for human pathogen transmission, fresh manure should not be used on vegetables, especially root crops.

Composted Manure

  • Composting manure addresses several issues associated with fresh manure, including odor and weed seeds.
  • Composted manure has lower nitrogen availability but contributes more to the organic matter content of the soil.
  • Immediate incorporation into the soil is not as crucial as with fresh manure, but it is still recommended for maximum benefit.

Nutrient Availability and Application Rates

The nutrient content of manure varies depending on factors such as animal type and bedding material.

  • Typically, 70-80% of phosphorus and 80-90% of potassium become available in the first year after application.
  • Nitrogen availability is more intricate, relying on microbial activity.
  • Recommended application rates for fresh manure or compost are provided based on the desired nitrogen supply.

Safety Considerations in Manure Application

Non-composted manure can harbor harmful bacteria that may contaminate vegetables and pose health risks.

  • Proper composting is essential to eliminate these bacteria.
  • USDA National Organic Program rules specify the minimum interval between non-composted manure application and vegetable harvest to minimize bacterial contamination risks.

Conclusion

Manure, when used judiciously, serves as a valuable soil amendment, enhancing soil quality and promoting plant growth. Understanding the different types of manure, their nutrient content, and proper application techniques is crucial for effective and safe manure utilization in agricultural practices.

FAQs

What is the best type of manure to use?

  • Manure from herbivores like cows, sheep, and chickens is commonly used as fertilizer. Avoid manure from cats, dogs, or pigs in vegetable gardens or compost piles.

Can I apply fresh manure directly to my garden?

  • Fresh manure, especially poultry manure, is high in ammonia and should be incorporated into the soil within 12 hours of application to prevent nitrogen loss. Fresh horse manure may contain weed seeds, so use it cautiously. Avoid using fresh manure on vegetables, particularly root crops, due to potential pathogen contamination.

What are the benefits of composted manure?

  • Composting manure eliminates odor, reduces weed seeds, and kills harmful bacteria. It contributes more to the organic matter content of the soil but has lower nitrogen availability compared to fresh manure.

How do I determine the right amount of manure to apply?

  • Application rates depend on the desired nitrogen supply. Follow recommended rates based on the type of manure (fresh or composted) and the specific crop’s nitrogen requirements.

How often should I apply manure to my soil?

  • Manure application frequency depends on the type of manure, soil conditions, and crop needs. Consult local agricultural extension services or soil testing results for specific recommendations.

What are the safety precautions when handling manure?

  • Wear gloves and protective clothing to avoid direct contact with manure. Wash hands thoroughly after handling manure. Avoid using fresh manure on vegetables that come in contact with the soil to minimize the risk of bacterial contamination.

Can I use manure from my pets in the garden?

  • It is generally not recommended to use manure from pets (cats, dogs, etc.) in vegetable gardens due to the potential presence of harmful bacteria and parasites.

Are there any regulations or guidelines for manure application?

  • Some regions may have regulations or guidelines regarding manure application, particularly for commercial farming operations. Check with local authorities or agricultural extension services for specific requirements in your area.