Agricultural conservation practices in Iowa watersheds: comparing actual implementation with practice potential

Area of Science:

• Environmental Science
• Agricultural Science
• Water Resource Management

Background:

• The Gulf of Mexico hypoxia necessitates nutrient load reduction strategies.
• Iowa's Nutrient Reduction Strategy (INRS) aims for a 45% N and P reduction by 2035.
• Agricultural non-point source pollution is a key target for conservation practices.

Purpose of the Study:

• To compare the potential placement of conservation practices with actual implementation in Iowa watersheds.
• To evaluate the effectiveness of the Agricultural Conservation Planning Framework (ACPF) and Iowa Best Management Practices Mapping Project (IBMP) in conservation planning.
• To identify gaps and opportunities for improving conservation practice implementation.

Main Methods:

• Utilized the Agricultural Conservation Planning Framework (ACPF) to identify potential conservation practice locations.
• Employed the Iowa Best Management Practices Mapping Project (IBMP) to map existing conservation practices.
• Compared ACPF-identified potential with IBMP-identified actual implementation for grassed waterways, wetlands/ponds, and WASCOBs in three HUC-12 watersheds.
• Analyzed implementation differences across distinct Iowa landform regions.

Main Results:

• Grassed waterways show high implementation rates (≥78% of potential) across studied watersheds.
• Existing ponds and wetlands are generally smaller than ACPF-identified potential sites.
• Water and Sediment Control Basins (WASCOBs) implementation varied significantly by watershed, likely due to regional preferences.

Conclusions:

• The IBMP and ACPF are valuable tools for watershed stakeholders to plan future conservation investments.
• A systems-based approach to conservation planning is advanced by integrating potential and actual practice data.
• Understanding regional differences in conservation practice adoption is crucial for effective strategy implementation.