Reducing Environmental Contamination from Feedlot Manure in the South Platte River Basin through Agronomic, Economic, and Social Analysis and Education

Project Overview

Project Type: Research and Education
Funds awarded in 1996: $206,000.00
Projected End Date: 12/31/1999
Matching Non-Federal Funds: $73,191.00
Region: Western
State: Colorado
Principal Investigator:
Dr. Jessica Davis
Colorado State University

Annual Reports


  • Agronomic: corn
  • Animals: bovine
  • Animal Products: dairy


  • Animal Production: manure management
  • Crop Production: nutrient cycling, organic fertilizers, tissue analysis
  • Education and Training: technical assistance, demonstration, extension, farmer to farmer, on-farm/ranch research, participatory research
  • Farm Business Management: budgets/cost and returns, value added, whole farm planning
  • Pest Management: field monitoring/scouting
  • Soil Management: composting, earthworms, organic matter, soil analysis, soil quality/health
  • Sustainable Communities: partnerships


    Impacts of manure application rates on crop yields, nitrate levels, weed and insect populations, and microbial biomass were examined in a two year field test on two farmers' fields. One field had a clay soil with no manure application history, and the other field had a sandy soil with a long history of manure application. Over application of manure did not improve yield and can harm soil and water quality. Manure application increased soil nitrate within and below the rootzone in early summer. Manure application increased microbial biomass nitrogen, suppressed proso millet germination, but had no effect on corn rootworm. A study with ten manure haulers showed that most manure haulers do achieve their application rate goals, but about two thirds of them had poor spreader uniformity. A survey of 270 farmers showed that producers value manure at $3.85 per ton due to its positive impact on soil properties. We held eight workshops for livestock producers and helped 53 producers develop manure management plans for their farms.

    Project objectives:

    Research Objectives

    1. Determine optimum feedlot manure application rates and accompanying N fertilizer needs for silage corn and to use the pre sidedress soil nitrate test and the chlorophyll meter as a guide for in season N recommendations in manured fields.

    2. Determine crop water use and nitrate loss below the root zone as a function of manure application rate and timing.

    3. To evaluate the effect of manure rates on soil quality and microbial populations and on pest populations (weeds, diseases, insects) and management recommendations.

    4. Compute the costs and returns to alternative management schemes, determine economic returns and constraints for hauling, and understand the decision making processes and relationships of persons and organizations in the chain from feedlot stocks of manure to potential users of manure as a fertilizer.

    Education Objectives

    1. Change the perception of manure as a waste to its being viewed as a valuable resource and to increase the use of manure credits so that applications will be made at agronomic rates and environmental problems minimized.

    2. Encourage feedlot operators to conduct manure testing and to give the nutrient analysis of each load to the recipient.

    3. Train manure haulers/spreaders in calibration of their equipment and proper application techniques.

    4. Teach consultants, fertilizer dealers, and producers to base fertilizer recommendations on soil testing, manure analysis and calibration, the pre sidedress soil nitrate test, and chlorophyll meter measurements.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.