AGRICULTURAL BEST MANAGEMENT PRACTICE SENSITIVITY TO CHANGING AIR TEMPERATURE AND PRECIPITATION

Area of Science:

• Environmental Science
• Agricultural Science
• Climate Science

Background:

• Agricultural best management practices (BMPs) are crucial for reducing non-point source pollution from croplands.
• Current water quality management plans often rely on historic climate data for BMP effectiveness estimates.
• Future climate change, including rising temperatures and altered precipitation, poses risks to water quality goals.

Purpose of the Study:

• To investigate how future climate change scenarios impact the effectiveness of common agricultural BMPs.
• To assess the performance of specific BMPs under projected temperature and precipitation patterns.
• To determine if current BMP strategies will be sufficient to meet future water quality targets.

Main Methods:

• Utilized the Soil and Water Assessment Tool (SWAT) for hydrological and water quality modeling.
• Simulated two distinct agricultural watersheds (Minnesota Corn Belt, Georgia Coastal Plain) under various climate scenarios.
• Evaluated the effectiveness of conservation tillage, no-till, filter strips, grassed waterways, nutrient management, cover crops, and drainage water management.

Main Results:

• Projected increases in agricultural source loads of sediment, nitrogen, and phosphorus under future climate conditions.
• Most BMPs demonstrated continued pollutant load reduction, but with generally declining removal efficiencies.
• Reduced BMP efficiency is linked to intense runoff, altered soil moisture/temperature, and increased upland loading.

Conclusions:

• Future climate change is expected to increase agricultural pollutant loads.
• The effectiveness of widely adopted BMPs may decrease, necessitating adjustments.
• Meeting water quality goals may require wider implementation, resizing, or combining of BMPs.