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Nutrient Management

Using Manure Nutrients Wisely

Farmer in corn field

The nutrients in dairy waste are essential to plant growth and have been used to fertilize crops for thousands of years. Ideally on a modern dairy, manure is recycled as fertilizer for corn and other crops that feed the cows. This makes for a healthy nutrient recycling system that reduces pollution and resource consumption.

However, the amount of animal waste on any particular dairy does not always match the amount and timing of the crops' need for nutrients. Over-application of dairy waste can pollute groundwater with nitrates and salts. This is an important issue in California's San Joaquin Valley, which is home to most of California's dairies.

Many California dairies are out of balance in their manure management, meaning that their cows are producing more manure than their crops can utilize, based on the current farming practices and technologies. The good news is that there are solutions that protect clean water.

Our Role

The technologies and practices Sustainable Conservation promotes help dairy farmers apply manure nutrients in precise amounts, and at the right time in their crop's growth cycle, so farmers fully utilize available nutrients and produce high-quality forage crops while meeting water quality standards. We test promising technologies and practices, and promote the most effective ones. We provide farmers with practical options to make the best use of these methods. We help find answers to their questions, and help farmers get the funding and other resources they need to implement effective solutions.

For example, we launched the Nutrients on Demand project in collaboration with the California Dairy Quality Assurance Program, Western United Environmental Services, and the Source Group Inc. Under the project, we and our partners work directly with dairy farmers to: improve nutrient management practices in order to minimize nutrient losses and protect water quality, emphasize the economic benefits of efficiently managing nutrients, and provide dairy producers with tools to achieve regulatory compliance.

We also developed a Nutrient Management Field Guide in partnership with several organizations, including Western United Dairymen, the Natural Resources Conservation Service, California Dairy Campaign, The Source Group, Inc. and UC Davis. The field guide gives dairy farmers tools for customizing their nutrient management practices. It provides concrete information about crop nutrient uptake, crop water use, irrigation flow rates and lagoon water nutrient concentration. With the right infrastructure and tools, a dairy farmer can monitor and adjust the amount of nutrient-rich lagoon water that is applied to crops.

We host field days, workshops and seminars; publish a nutrient management newsletter; speak at industry conferences; and lead other education and outreach efforts.

When effective nutrient management practices are widely adopted by California dairy farmers, the groundwater will recover, local streams and rivers will run cleaner and dairy farmers can continue feeding California families profitably.