Mob grazing effects on nutrient runoff in cool season pastures

2012 Annual Report for GS12-113

Project Type: Graduate Student
Funds awarded in 2012: $10,974.00
Projected End Date: 12/31/2014
Grant Recipient: Virginia Tech
Region: Southern
State: Virginia
Graduate Student:
Major Professor:

Mob grazing effects on nutrient runoff in cool season pastures

Summary

A comparison of stocking method effects on surface runoff quantity and quality is ongoing. The stocking methods to be evaluated are 1) continuous stocking, 2) rotational stocking, and 3) mob stocking. Data from the first year (2012) has been collected. A total of 63 rainfall simulations were performed during the 2012 grazing season. Stocking method impacts on runoff quantity and nutrient losses have been observed, but further investigation of other factors is necessary. Plans are in place to collect data for a second year of the study during the 2013 grazing season.

Objectives/Performance Targets

1. Compare runoff volumes among mob, rotationally, and continuously stocked pastures.
2. Compare sediment losses in runoff among mob, rotationally, and continuously stocked pastures.
3. Compare nutrient losses in runoff from mob, rotationally, and continuously stocked pastures.

Accomplishments/Milestones

63 rainfall simulations were completed during the 2012 grazing season. 10 rainfall simulations occurred prior to stocking and 53 rainfall simulations were performed post-stocking. Water quality analysis has been completed for four subsamples (timed at 10 minute intervals after initiation of runoff) for each rainfall simulation. Statistical analysis of treatment effects on runoff quantity and quality has begun.

Impacts and Contributions/Outcomes

This research will provide a comparison of the effects on runoff quantity and quality of mob stocking to other stocking methods. In the end, this research will be utilized by USDA-ARS to develop protocols and tools for field data collection in order to classify ecological response units as defined by the Pastureland Conservation Effects Assessment Project (CEAP). Data from these initiatives will be used by CEAP to develop and refine models such as the Soil and Water Assessment Tool (SWAT) to provide information on the water quality benefits of pastureland conservation practices at larger scales. This work is a joint effort with USDA ARS scientists to develop a regionally-based understanding of nutrient transport and fate in pasture-based systems relative to implementation of conservation practices.

Collaborators:

Dr. Cully Hession

chession@vt.edu
Professor
204 Seitz Hall, Virginia Tech
Blacksburg, VA 24061
Office Phone: 5402319480