Commodities

Practices

• Animal Production: manure management
• Crop Production: application rate management, nutrient cycling, nutrient management
• Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research, workshop
• Farm Business Management: budgets/cost and returns
• Natural Resources/Environment: carbon sequestration, soil stabilization
• Production Systems: agroecosystems, dryland farming, integrated crop and livestock systems
• Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil quality/health

Problem

Although manure is a high-quality soil amendment, its management system can degrade air and water quality. Manure nitrogen volatilization as ammonia impacts both human health through the formation of atmospheric PM2.5 and reduces biodiversity through deposition in natural areas such as Rocky Mountain National Park. Northern Colorado’s semi-arid environment combined with common manure management practices such as open lots, uncovered manure storage, and broadcast manure application make dairy systems hotspots for ammonia emissions in the state.

Solution

Variable rate application (VRA), a precision manure management strategy, adjusts manure volume application to reduce over-application of manure nutrients. While VRA by volume provides more control over nutrient placement within a field, over- or under-application of some nutrients due to the inability to adjust rates based upon manure’s heterogeneous nutrient composition or to optimize application rates for multiple nutrients. For example, setting application rates by voluShare findings and data with the broader community via a
publicly available ammonia emissions database.me to meet plant nitrogen needs may result in over-application of phosphorus.

Recent advancements in VRA use NIRS sensors to measure manure nutrient composition real-time, enabling autonomous adjustment of application rates in the field. This technology refines existing VRA technology as it can be optimized for multiple criteria (e.g., minimize both nitrogen and phosphorus), which may further reduce environmental impacts by more precisely matching application rates to plant needs.

This project was developed in coordination with local manure applicators, a dairy farm manager, a large dairy operator, and dairy industry partners including a manure management school facilitator, an equipment dealer, and a manufacturer. The objective of this proposal is to evaluate the potential for manure sensors to contribute to reduced ammonia losses from manure application and improve soil health in Colorado’s croplands. Its findings will be disseminated in coursework and a demo day hosted in collaboration with CSU Extension, 4Rivers Equipment, and Puck Enterprises.

Research Objectives

1. Compare ammonia losses from variable rate manure application (VRA) with and without manure sensors with those of the most common CO manure management practices.
2. Evaluate the impact of variable rate manure injection with and without the use of NIRS manure sensors on soil N dynamics and key soil health parameters (g., bulk density, soil organic carbon, aggregate stability, electrical conductivity, and soil microbial communities).
3. Compare the impact of variable rate dairy manure injection with and without manure sensors on crop yield and quality.
4. Complete a cost-benefit analysis of dairy manure application with the use of manure sensors.

Education Objectives

1. Incorporate research findings into existing undergraduate cropping systems, agroecosystem management, and manure management courses.
2. Facilitate technology transfer via a Northern Colorado Manure Tech Demo Day and Extension bulletins.
3. Provide a professional development opportunity by offering an optional 2-day manure management training in conjunction with the demo day, with the opportunity to earn a manure management certificate upon completion.
4. Share findings and data with the broader community via a publicly available ammonia emissions database.