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Estimates of Manure Nutrients

Estimates of Recoverable and Non-Recoverable Manure Nutrients Based on the Census of Agriculture

The structure of animal agriculture continues to shift toward fewer and larger operations, concentrating livestock in local areas. As a consequence, the utilization and disposal of animal manure from animal feeding operations continues to be an important farm management challenge if producers are to be successful in reducing water quality degradation related to land application of manure. When nutrients are recycled on the land at rates that exceed the capacity of the land to utilize the nutrients, continued manure applications can lead to a buildup of nutrients in the soil. This increases the potential for nutrients to move from the field through leaching and runoff to pollute groundwater and surface water.

This study provides insight into issues associated with the increasing concentration in the confined livestock industry. We inform policy initiatives and policy choices by describing the recoverable manure nutrients, the excess nutrients, and areas with excess nutrients. By describing these changes in indicator variables, we establish an "upper" bound on the reach of policies to manage manure nutrients. In addition, we provide a consistent comprehensive data set for further analysis by NRCS and other natural resource agencies.

This study used data from seven Censuses of Agriculture from 1982 through 2012 to estimate the quantity of recoverable (generally concentrated in a small area) and non-recoverable (generally dispersed over the landscape as with grazing animals) manure nutrients produced by the animal agriculture sector. Using Census inventory and sales data, we estimated manure nutrients based on estimates of the number of animal units, by animal type, for each Census farm. Based on animal numbers and type, farms were classified into groups of no livestock, livestock farms with non-recoverable manure, and two size classifications of livestock farms with recoverable manure; the smaller generally referred to as animal feeding operations (AFOs) and the larger generally referred to as concentrated animal feeding operations (AFO-CAFOs). (CAFOs are defined by the Environmental Protection Agency using animal numbers and farm conditions. We can only estimate the number of AFOs that are potential CAFOs, hence AFO-CAFO.) Estimates of the quantity of manure were based on literature coefficients and the average animal unit numbers per operation.

The full text of these publication are available in Adobe Acrobat format:

Full Report 1982 - 2007

Estimates of Recoverable and Non-Recoverable Manure Nutrients Based on the Census of Agriculture 1982-2007 (PDF; 16.0 MB)

Database of Estimates by 6-Digit HUC of Animal Units and Recoverable and Non-Recoverable Manure Nutrients based on the 2007 Census of Agriculture (PDF; 1.1 MB)

Supplement for 2012

Estimates of Recoverable and Non-Recoverable Manure Nutrients Based on the Census of Agriculture - 2012 Update (PDF; 4.8 MB)

Database of Estimates by 6-Digit HUC of Animal Units and Recoverable and Non-Recoverable Manure Nutrients based on the Census of Agriculture - 2012 Update (PDF; 0.3 MB)

Full Report 1982 - 1997

Manure Nutrients Relative to the Capacity of Cropland and Pastureland to Assimilate Nutrients 1997

CNMP Report 2003

Costs Associated with Development and Implementation of Comprehensive Nutrient Management Plans 2003