2009 Annual Report
1a.Objectives (from AD-416)
Research objectives developed in this CRIS are focused on the engineering aspects of managing nutrients in beef cattle manure while minimizing environmental degradation. Our objectives are:.
1)improve and evaluate alternative feedlot runoff control systems using vegetative treatment areas (VTA):.
2)refine EMI techniques for management of cover crop on cropland and movement of nutrients on the feedlot surface:.
3)develop techniques to determine emission flux and area contributing to gaseous emissions from cattle feedlots. Data collected could be used by computer models for predicting gaseous concentrations down wind:.
4)evaluate the occurrence, transmission, and persistence of zoonotic pathogens and fecal indicators in a beef feedlot runoff control with a VTA and identify characteristics that are particularly effective in limiting the movement of zoonotic pathogens and fecal indicators through different vegetative treatment areas, to support development of recommendations that can be implemented by feedlot operators.
1b.Approach (from AD-416)
The MARC beef cattle feedlot provides a site for testing various manure management issues. Odor generation and control at the feedlot surface will be investigated with gas emission chambers developed in-house. The feedlot surface will be scanned with an electromagnetic induction meter to precisely locate manure concentrations. Manure from the feedlot will be applied to cropland for utilization where nitrogen management practices, such as winter cover crop, will be evaluated. Precipitation runoff from the feedlot will be controlled with alternative technology that eliminates the need for long-term liquid storage and distribution of liquid on grassed fields. Transport and survival of pathogens contained in manure will be monitored as the runoff passes through the control system and deposited on the vegetation treatment area.
ARS scientists developed an alternative runoff control and treatment system designed to reduce long-term liquid storage, provide solids separation, and distribute basin discharge water and nutrients for hay production. Five vegetative treatment areas (VTA) were approved by the Nebraska Department of Environmental Quality and successfully constructed at USMARC. These systems effectively reduced the mass of nutrients and volatile suspended solids discharged from the basin. The nutrients contained in the basin solids are removed annually and applied to cropland as soil amendment. The basin discharged nutrients are distributed to a vegetative area. Demonstrated system sustainability has been documented; the amount of nutrients removed in the harvested hay is equal to or exceeds the amount deposited by the basin discharge.
Proper VTA management requires an understanding of nutrient distribution across the hayfield. Soil conductivity maps generated by subsurface sensors using electromagnetic induction have been used to provide valuable insights into this distribution. However, these maps provide little specific information on nutrients of environmental concern. A technique was developed using subsurface sensor data to identify optimal sample locations for collecting soil samples. Soils information from these samples was combined with sensor data to produce nutrient specific predictive models. These models were then used to generate illustrative maps enabling producers to monitor system performance, adjust nutrient distribution, and improve overall performance and sustainability.
A study of a USMARC VTA examined the prevalence of both Escherichia coli O157 and Campylobacter spp. These pathogens are shed by cattle housed in pens, and have been recovered from soils, basin sludge, and basin water. Basin discharge can introduce E. coli O157, Campylobacter spp., and generic E. coli into the VTA. Without additional inputs from the basin, isolation frequencies of E. coli O157 and Campylobacter spp. from VTA soils decrease over time. The isolation of generic E. coli on fresh-cut hay from regions of the VTA that received runoff (3/15 vs. 0/15 control samples) indicates some pathogen risk. E. coli O157 was isolated from only one of 30 treatment samples prior to baling. Neither pathogen was recovered from hay following baling.
Many commonly used methods to measure emissions can provide estimates of average emissions over large areas. However, they cannot identify specifically where the emissions originate or provide a measure of the effectiveness of management practices designed to reduce them. A method was developed that uses subsurface sensors to identify zones of manure accumulation using a minimal number of calibration sampling sites from the feedlot surface. The technique used is very similar to the methods applied to measure VTA distribution and sustainability. Correlation of the specific subsurface signal to the emission constituent of interest was accomplished using various analytical approaches.
Using sub-surface sample technology, prediction-base sampling approaches, and statistical modeling to identify manure accumulation zones on feedlot pen surfaces. A method was developed using subsurface sensors that directed a sampling strategy based on this information. This subsurface data was used to generate statistical models to predict variability of manure accumulation on the feedlot surface. Soil measurement and positional data from global positioning satellites were collected using transects across the feedlot pen surface. Two sampling approaches were used to validate the method. One sampling approach selected sites randomly. Data from this sampling approach was used as an independent test to evaluate the other sampling approach using sub-surface sampling information to select optimum sample sites. The method using the sub-surface sampling data produced better estimates of manure accumulation zones within the pen than the random method. Excellent correlations between the sub-surface survey data and measured soil properties suggest the developed method can be used to map variable manure accumulation zones within feedlot pens. Combining sub-surface survey data with calibration soil sample enables researchers to generate maps illustrating manure accumulation zones on pen surface. This technique allows researchers to evaluate precision management practices to reduce environmental contamination from beef feedlots. Also, this method enables producers to accurately harvest zones containing high-value volatile material which can be used as a combustion material in conjunction with coal-fired steam generation.
|Number of Invention Disclosures Submitted||1|
Eigenberg, R.A., Lesch, S.M., Woodbury, B.L., Nienaber, J.A. 2008. Geospatial methods for monitoring a vegetative treatment area receiving beef feedlot runoff. Journal of Environmental Quality. 37(5,Supplement):S68-S77.
Hooks, T., Marx, D.B., Kachman, S.D., Pedersen, J.F., Eigenberg, R.A. 2008. Analysis of covariance with spatially correlated secondary variables. Revista Colombiana de Estad istica 31:95-109. 2008