Rotational Grazing on Land Receiving Manure Applications; Impacts of Land Management Practices on Soil and Water Quality

Rotational Grazing on Land Receiving Manure Applications; Impacts of Land Management Practices on Soil and Water Quality

Summary

Project collaborators initiated investigations to compare the impacts of continuous and rotational grazing practices on soil and water quality. A combination of on-station and on-farm research studies are being used to examine the impacts of grazing practices on nutrient runoff, soil erosion, pasture growth and diversity, as well as on soil chemical, physical, and biological characteristics. This information will be used to assist farmers to implement productive grazing practices that protect water quality. It will also be used to influence the formation of technical guidelines and regulatory policies for applying manure to grazed lands.

Objectives/Performance Targets

1. Evaluate the effects of year-round grazing management on pasture hydrology, nutrient loss associated with surface runoff, soil quality, and animal production.

   Evaluate the impact on soil and water quality parameters according to the length of time paddocks have been rotationally grazed.

   Evaluate on-farm and off-farm costs and benefits from grazing practices under assessment.

   Collaboratively develop Water Quality Checksheets for Pastures, which farmers and agricultural professionals can use to monitor soil and water quality on grazed fields.

   Use experimental results to recommend pasture management practices as modifiers in calculating the Arkansas phosphorus index.

Accomplishments/Milestones

• At the USDA-ARS research station in Booneville, Arkansas, University of Arkansas and USDA-ARS collaborators established pasture/runoff plots designed to compare rotational grazing against ungrazed hayland and three continuous grazing treatments: without buffers, with grass buffers, and with tree buffers. By using funds from other sources, automated runoff sensors were installed on each plot. These sensors will allow for the precise measurement of sediments and dissolved nutrients transported from the plots.

  Runoff and sediments will be collected and analyzed from these on-station research plots for approximately one year prior to putting cattle in the pastures. This will allow time for the plots to recover from disturbances caused by their construction, for buffers to become established, and for a complete season of baseline data to be collected prior to the initiation of research assessments.

  NCAT collaborators coordinated the establishment of three on-farm studies in Arkansas and Oklahoma. On each site, paired pastures with the same soil type were selected to compare pastures that have been in rotational grazing for at least eight years with neighboring pastures that have been subjected to long-term continuous grazing.

  Baseline soil quality assessments, including soil nutrient and organic matter analyses, bulk density, soil compaction, and microbial biomass, will be completed on both on-station and on-farm research plots by Spring 2003.

  In conjunction with ATTRA project activities, two outreach publications and a Power Point presentation were developed on the topic of grazing practices to protect riparian areas. These materials will be used during demonstration-workshops. Additional materials on soil and water quality indicators for pastures will be developed prior to conducting demonstration-workshops in Spring 2003.

  Demonstration-workshops will be initiated in Spring 2003. Two workshops, to be held in conjunction with field days at the USDA-ARS Bumpers Small Farm Research Station in Booneville, Arkansas, and the Kerr Center in Poteau, Oklahoma, will describe the research studies and engage participants in discussions to identify land-use recommendations and on-farm indicators to assist farmers implementing grazing practices that protect water quality. Additional workshops will be held in conjunction with meetings of farmers involved in grazing networks.

  Economic analyses of the costs and benefits of grazing practices on water quality will focus on management expenses, animal growth and profitability, water quality, and costs of water treatment for various uses. These studies will use data from both on-station and on-farm studies.

  Reserach studies, along with farmer inputs, will produce integrated biological, chemical, economic, and sociological analyses of grazing practices and related differences in water quality characteristics. This data will be used to support recommended revisions to phosphorus-indexes, nutrient management planning, and other guidelines used by technical and regulatory agencies and organizations to assess the potential impact of animal agricultural practices on water quality.

Impacts and Contributions/Outcomes

The impact and contributions of this project will be three-fold:
1) an analytical understanding of the impact of different grazing practices on nutrient runoff and sediment loss;
2) participatory development of farm-based land-management and assessment tools to help farmers implement grazing practices that protect water quality, and
3) the development of land use policies for grazing lands that are based on a combination of scientific information and farm-based perspectives.

Collaborators: