Code of Practice Standard
Download the 2024 Code of Practice
Purpose: To establish reasonable and practicable guidelines for nitrogen fertilization applications to reduce nitrate loss from farm fields.
Why: Effective management of nutrients on farms in Iowa is one of the keys to enhancing both environmental quality and profitable crop production. Consistent with the Iowa Nutrient Reduction Strategy, this Code of Practice provides information about guidelines adopted by the ACWA members as a condition of membership.
Photo Credit: Heartland Co-op
Application Guidelines
- A nutrient recommendation for nitrogen and phosphorus shall be developed that considers all potential sources of nutrients including manure, legumes, etc. Nutrient recommendations shall be based on current soil test results, realistic yield goals, environmental impact, producer management capabilities, and leveraging 4R nutrient stewardship practices.
- Delay fall anhydrous applications without a nitrification inhibitor until soil temperatures are 50⁰ F, trending lower.
- Regardless of time of year application occurs, encourage use of other supporting nutrient management technologies such as stabilizers, slow-release fertilizers, incorporation or injection, soil nitrate testing and other technologies that minimize loss to surface or groundwater resources.
- If the producer is participating with USDA Conservation Programs, additional considerations for producer conformance with NRCS 590 Nutrient Management standards shall be followed. For guidance and requirements see standard: 590 Nutrient Management (usda.gov)
- Encourage the use of other supporting practices where feasible:
– Tile line denitrification bioreactor
– Constructed wetland
– Conservation stream buffer and/or saturated buffer strips
– Fall cover cropping system
– Split and/or variable rate nitrogen applications. See Iowa 4R Plus website for specific details: The 4Rs of Nutrient Management and Stewardship | 4R Plus
Self-Reporting
- Use one of two methods to document soil temperature at the time of application decision:
- Standardized county temperature and forecast maps found at: https://www.mesonet.agron.iastate.edu/agclimate/soilt.php
- 4″ in-field soil temperature check and reading recording method used on self-reporting form.
- Use On-line ACWA Self-Reporting System to document conformance with requirement:
- Regular ACWA Board Member assigns staff responsibility to report start of application for all counties within member trade area.
- Self-reporting system is on-line at: ACWA Self Recording Form (a specific username and password has been assigned for each member organization). Simple, easy, takes less than 1-minute to complete on computer, cell phone, or other electronic devices.
- Any questions contact: Roger Wolf, ACWA Executive Director, roger@acwaiowa.com, 515-205-9225, or Kristen Dearden, ACWA Membership Services & Communications Coordinator, kristen@acwaiowa.com, 515-334-1482.