Best Management Practices for Reducing Ammonia Emissions

 Ammonia volatilization can be reduced by adhering to (BMPs) for fertiliser rate, source, and kind, as well as fertiliser application time and manner. Recognizing potential concerns with each is critical to minimising these damages.

·       SOLID MANURE

Solid manure is generated on drylots and is frequently retrieved by scraping it off the pen surface. Dairy freestall manure can subsequently be placed to solid manure mounds or left to dry. The best way to stop ammonia emissions from manure application sites is to mix the manure as soon as possible into the soil.

This significantly lowers volatilization losses caused by air exposure. Ammonia leakage can be reduced by 85-90 percent when surface-applied manure is incorporated immediately (within 1 hour).Even achieving inclusion in less than 24 hours is valuable. To ensure adequate N conservation, the depth of integration can be as little as 2-4 inches.

·       SLURRY MANURE

Slurry manure can be created on dairies that employ a suction method to collect manure. We explain a range of application strategies for mixing manure slurry into soil below; nevertheless, injecting is by far the most efficient and successful method of decreasing ammonia loss from slurry manure application to land.

·       LIQUID MANURE

Liquid manure can be created on dairies that employ a flush way to collect manure from freestalls or on feedlots that irrigate runoff water onto adjoining fields. Because liquid manure contains 98-99 percent water, it is typically administered via sprinkler irrigation systems.

Fertigation with liquid manure can be an efficient approach to give N to crops if the time is coordinated to suit crop N needs. Furthermore, if 34 inches or more of water is applied at one time, the water itself acts as a mechanism of incorporating the N below the soil surface. Turning off a centre pivot's end gun and using drop nozzles can help to reduce NH3 loss during an irrigation event.

·       Timing manure application

Manure application timing can aid in reducing ammonia volatilization and retaining nitrogen. Nitrogen loss can be reduced by limiting applications on hot, windy conditions or when the climate is expected to be sunny and dry. In one study, applying manure at 54° F and 75 percent relative humidity reduced emissions by 10% when compared to 59° F and 60 percent relative humidity.

However, it is not often possible to wait for perfect environmental circumstances, applying immediately before a light rain on a cool, cloudy day, or in the early morning or evening (rather than in the middle of the day), will help to limit ammonia volatilization and enhance nitrogen availability.

·       Applying manure at agronomic rates

In order to avoid over-applying nitrogen and raising the risk of ammonia loss, it is vital to apply manure at agronomic rates. Test the nutritional content of your manure on a regular basis to maintain that application rates correspond to crop nutrient requirements.

Furthermore, understanding crop requirements and manure nutrient levels might aid in avoiding over-application. To enhance efficiency and limit emissions, apply only what is necessary based on soil type, yield goals and nitrogen availability.