Tag: bedpack

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Modeling water movement in beef cattle bedded manure pack


Why Examine Moisture Content of a Manure Pack?

Bedded manure is a valuable fertilizer source because it contains essential macronutrients (nitrogen (N), phosphorus (P), and potassium (K)) for crop production. Previous research with beef cattle bedded manure packs demonstrated that water-soluble macronutrients accumulated toward the bottom of the packs with water movement. Thus, predicting water movement in bedded manure helps to estimate nutrient composition throughout the bedded pack. This work presents a development of a process-based model of vertical water movement that considers percolation and diffusion as the main processes of water and vapor movements in bedded manure packs. Evaporation from the top zone to the atmosphere was considered a process of convective mass transfer. The model predicts the change in moisture content of the different zones in the bedded manure and assists in estimating nutrient composition.

cattle loafing on a bed pack in their barnWhy Study Moisture Movement In a Bedded Pack?

Beef cattle producers that raise cattle in complete confinement, such as mono-slope or hoop barns, may apply bedding material to manage moisture and improve the environment for the animals. Some producers let the manure and bedding accumulate to form a bedded manure pack, which is compacted by cattle activity. The bedded manure contains valuable nitrogen (N), phosphorus (P), and potassium (K) that are essential for crop production and soil sustainability. Depending on temperature, bedding material, and storage time of the bedded pack, the concentration of water-soluble N, P and K compounds may increase in the bottom of the bedded pack where water accumulates. Thus, understanding and predicting water movements within the bedded manure is important to estimate fertilizer N-P-K content and distribution in the bedded manure.

What did we do?

The processes considered in this process-based model include evaporation, percolation, diffusion of water vapor and diffusion of liquid water for vertical water movement. The model by Seng et al. (2012) for static compost piles and a modified version of the Integrated Farm System Model (not yet released) by Rotz et al. (2014) for bedded manure were reviewed and compared. Ultimately, the model needs to be adaptable to estimate the water content of the pack over time for different environmental conditions, bedding materials, and storage times at varying depths within the bedded pack. Data for model calibration and validation were gained through laboratory-scale experiments by Ayadi et al. (in review).

What have we learned?

Percolation and liquid water diffusion are considered the main processes for vertical water movement between layers in the bedded manure. Evaporation occurs from the surface of the top zone of the bedded pack. The rates of percolation and liquid water diffusion are depth-specific and their rates therefore vary. The modified version of the Integrated Farm System Model (IFSM) is more adaptable to data gained through laboratory-scale experiments. Overall, IFSM is more applicable to producer-available data and thus more applicable to predict water movement for bedded manure packs in real-life conditions.

Future Plans

After predicting water movements in the bedded manure, the model will be used to estimate N, P and K movement through the different zones of the bedded manure pack as well as gaseous emission (ammonia and nitrous oxide) from the bedded pack surface. The final overall model will be a calculator that estimates fertilizer N-P-K content and value and ammonia and nitrous oxide emissions of the bedded manure packs from confined beef cattle facilities with respect to temperature, bedding material, storage time and depth of the bedded pack.

Authors

Erin Cortus, Ph. D., Assistant Professor, South Dakota State University, Brookings, SD

Ferouz Ayadi, M.S., Graduate Student, South Dakota State University, Brookings, SD; Mindy Spiehs, Ph. D., Animal Scientist, USDA‐ARS Meat Animal Research Center, Clay Center, NE

Additional information

References

Ayadi, F. Y., M. J. Spiehs, E. L. Cortus, and D. N. Miller. In review. Physical, chemical and biological properties of different depths and ages of simulated beef bedded manure packs. Transactions of the ASABE.

Rotz, C.A., Corson, M.S., Chianese, D.S., Montes, F., Hafner, S.D., Bonifacio, H.F., Coiner, C.U., 2013a.

The Integrated Farm System Model Reference Manual, Version 4.1. USDA-Agricultural Research Service. Avaialble at: http://www.ars.usda.gov/sp2UserFiles/Place/80700500/Reference%20Manual.pdf

Seng, B., H. Kaneko, K. Hirayama, and K. Katayama-Hirayama. 2012. Development of water movement model as a module of moisture content simulation in static pile composting. Environmental Technology 33(15):1685-1694.

Acknowledgements

The support and assistance of Henry F. Bonifacio with the simulation of water movements in the bedded pack manure is very much appreciated. This project and all associated reports and support materials were supported by the Sustainable Agriculture Research and Education (SARE) program, which is funded by the U.S. Department of Agriculture- National Institute of Food and Agriculture (USDA-NIFA). Any opinions, findings, conclusions or recommendations expressed within do not necessarily reflect the view of the SARE program or the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. The mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Manure management and temperature impacts on gas concentrations in mono-slope cattle facilities

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Why Study Air Emissions from Mono-slope Beef Barns?

Mono-slope buildings (Figure 1) are one type of roofed and confined cattle feeding facility that is becoming increasingly popular in the Northern Great Plains. However, little is known about the impact of these housing systems and associated manure management methods on the air quality inside and outside the barn.  The objective of this study was to determine gas concentrations in mono-slope beef cattle facilities and relate these concentrations to environmental and manure management factors.
Figure 1. View of a monoslope cattle facility from the northeast. Adjustable curtains in the rear (north) wall are used to limit airspeed through the barn during colder weather.

What Did We Do?

Four producer-owned and operated beef deep-bedded mono-slope facilities were selected for monitoring. Two barns maintained deep-bedded manure packs (Bedpack), whereas two barns scraped manure and bedding from the pens weekly (Scrape). Each site was monitored continuously for one month each quarter for two years to capture both daily and seasonal variations. At each facility, the environment-controlled instrument trailer and associated equipment were located adjacent to the barn. The trailer contained:  a gas sampling system (GSS) that consisted of Teflon tube sample lines connected to a computer-controlled sampling manifold, gas analyzers, computer, data acquisition system, calibration gas cylinders, and other supplies. In addition to the sampling lines, there were environmental instruments to measure the airflow and weather conditions for two pens in each barn. The analyzers and sensors used are summarized in Table 1.
Table 1. Analyzers and sensors used for air quality and environmental monitoring

Ammonia, hydrogen sulfide and methane concentrations were sequentially sampled from two south wall locations and three north wall locations per pen. The maximum hourly mean concentrations measured at the north or south wall of either pen in the barn were used in this analysis. The seasonal average hourly means of maximum concentrations and corresponding environmental variables were calculated.

What Have We Learned?
Figure 2. Seasonal averages of maximum hourly mean ammonia (a), hydrogen sulfide (b) and methane (c) concentrations for the bedpack and scrape manure management systems monitored in four monoslope cattle facilities, as influenced by ambient temperature.

The seasonal average hourly maximum ammonia concentration ranged from 0.6 to 3.3 ppm with the Scrape barns and from 0.2 to 7.1 ppm with the Bedpack barns (Fig 2a). The range of maximum hydrogen sulfide concentrations was 0 to 61 ppb in the Scrape barns and 0 to 392 ppb in the Bedpack barns (Fig 2b). The maximum methane concentration ranges were 4.9 to 10.6 and 3.1 to 15.8 ppm in the Scrape and Bedpack barns, respectively (Fig 2c). There are indications of differences between gas release rates for bedpack and scrape manure management systems and increased release rates with temperature for ammonia and hydrogen sulfide. Methane concentrations were more consistent between systems and for different temperature conditions.

This project expands the knowledge base of gaseous concentrations from deep-bedded beef barns. This integrated project also provides management techniques that producers can implement to minimize emissions, and improve air quality.

Future Plans

Emission values will be calculated using these concentration data, in conjunction with airflow data, which also varies with site and temperature conditions.

Authors

Erin L. Cortus, Assistant Professor, South Dakota State University, erin.cortus@sdstate.edu

Md Rajibul Al Mamun, Graduate Research Assistant, South Dakota State University

Ferouz Y. Ayadi, Graduate Research Assistant, South Dakota State University

Mindy J. Spiehs, Research Animal Scientist, USDA ARS Meat Animal Research Center

Stephen Pohl, Professor, South Dakota State University

Beth E. Doran, Extension Beef Program Specialist, Iowa State University Extension and Outreach

Kris Kohl, Extension Ag Engineer Program Specialist, Iowa State University Extension and Outreach

Scott Cortus, Engineering Research Technician, South Dakota State University

Richard Nicolai, Associate Professor (Retired), South Dakota State University

Additional Information

Acknowledgements

Project funded by Agriculture and Food Research Initiative Competitive Grant no. 2010-85112-20510 from the USDA National Institute of Food and Agriculture. Technical assistance provided by Alan Kruger, John Holman, Todd Boman, and Bryan Woodbury.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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