OCAMM 2010 Seminar Series

To read a summary of the presentation and discussion, click on the title of the seminar. 
For presentation slides and video recording, where available, click on the link.

Wednesday, Janaury 20, 2010 @ 2:00 pm

Evaluating the Potential for Nutrient Runoff on Ohio Cropland
Presented by: Dr. Robert Mullen, Ohio State University
Presentation slides

Wednesday, February 3, 2010 @
2:00 pm
Preliminary Investigation of the Impact of CAFO Manure Application on Water Quality in the Portage River Watershed
Presented by: Dr. W.Robert Midden, Bowling Green State University
Video presentationPresentation slides only.

Wednesday, February 17, 2010 @ 2 pm

Evaluating the Potential for Nutrient Runoff on Ohio Cropland
Presented by: Dr. Lingying Zhao, Ohio State University University                          
Presentation slides.

Wednesday, March 3, 2010 @ 2 pm

Ohio Lake Erie Phosphorus Task Force Report
Presented by:Kevin Elder, Ohio Department of Agriculture, LEPP                                   
Video presentationPresentation slides only.


Effectiveness of Field Edge Setback to Reduce Nutrient Transport
from Manure Application to Frozen/Snow Covered Fields

Dr. Robert Mullen, Ohio State University

Livestock farms with limited manure storage need to apply manure during the winter months but snow covered or frozen ground increases the risk of manure entering waters of the state during a thaw or rain event. Although USDA NRCS Practice Standard 633 provides application guidelines to minimize the risk, no data exist to support the recommended 200-ft setback from surface water.  In 2007, runoff plots were constructed at the Badger Farm, OARDC, Wooster to evaluate the effectiveness of the recommended setback.  Twelve 12-ft wide lanes, with a 2% slope, were constructed with bucket collectors at the down slope field edge to collect runoff.   Six lanes were 300-ft long, with manure applied along the upslope 100 feet on three lanes and with no manure on three control lanes.  Six lanes were 100-ft long and manure was applied to the entire lane to assess runoff with no setback; three control lanes did not receive manure. 

Manure was applied to the test lanes on January 28, 2008 followed by four sampling dates and on January 23, 2009 followed by three sampling dates observing the 633 Practice Standard for application rate and surface residue.  The runoff from each lane was collected following a thaw or rain event and analyzed for NH4-N, NO3-N, PO4-P, Total-P, and K.   For the 200-ft setback lanes, nutrient concentrations with manure were similar to those without it, indicating the effectiveness of the setback.  The exception was the fourth sampling date in 2008 in which the nutrient concentration in the runoff from the 200-ft setback lanes with manure was numerically higher than in those without manure, indicating that the effectiveness of the setback is limited as manure nutrients slowly move down slope during the winter months. Comparison between the 200-ft setback and no setback lanes that received manure, consistently showed a higher nutrient concentration for the no-setback lanes; however, the difference in nutrient concentrations was not always statistically significant.  The study concluded that the 200-ft setback will delay transport of nutrients down slope, but not indefinitely.  

To view presentations slides, click here.

Harold Keener (OSU): Will the study result in changes to NRCS guidelines?  Mullen:  Probably not, but based on discussions with NRCS and EPA, both seem to be more comfortable that existing guidelines are effective.

Robert Midden (BGSU):  How would subsurface drainage be expected to affect the results.  Mullen:  Practice Standard 633 does not address subsurface drainage; these soils would require different recommendations.  There would be minimal concern when the ground was frozen but during a thaw there could be transport to the drain tile.  The current study only assessed surface transport. 

David Munn (OSU):  1) Was the soil series Wooster or Canfield?  2) Could subsurface drainage have been present in the field?  Mullen:  1) Need to check on soil series.  2) The field was checked extensively for drain tiles and outlets but none were found.  They may be there but would assume they are old, clay tiles.

Munn:  Is the 200-ft setback from continuous or intermittent streams?  Mullen:  PS 633 may just refer to waters of the state.  Mark Duncan (SWCD):  Setback requirement includes any surface water.

Columbus participant:  How would you expect the results to change if urea or other synthetic fertilizers were applied at the same rate?  Mullen:  Although not evaluated, it may be of greater concern as the nutrients are designed to be more water soluble than manure nutrients.  Additional testing will be done in 2010 using diammonium phosphate.

Keener:  Which is more soluble di- or mono-ammonium phosphate?  Mullen:  Both are 85% soluble.

Fred Michel (OSU):  When is the best time to apply manure?  Mullen:  Ideally, it should be applied just before a small rainfall (~1/4 in) over several hours as this will increase vertical movement.  Unfortunately, there are a limited number of perfect application day, so the reality-based goal is to try to miss the worst days.

Keener:  Is the best time to top dress wheat during the freeze thaw cycle?  Mullen:  Generally, late March is considered the best time for a variety of reasons.  But many factors need to be considered including compaction of soil.

Warren Dick (OSU):  Does the solids content of the manure make a difference?  Mullen:  Yes, the higher the solid content, the less likely the manure will be transported.

Michel:  What is needed to reduce the N-P-K levels in the Mississippi River to 10% or less over its natural or background level.  Mullen:  Getting rid of tile drainage and reducing application rates; however, yields would decrease.  In reality it is a leaky system.

Michel:  If 200-ft setbacks were used everywhere, now much land would be taken out of production.  Mullen:  It depends on the area as some fields are in smaller segments than others.  Ideally, manure would first be applied on strip or no-till systems, then on tilled fields and finally on fields with filter strips.  Bulk P calculations over the past 50 years indicate that less is being applied and, nationwide, it is in balance; however, as the animals are more concentrated so is the manure.  The reality is you have to choose which problem to fix as fixing one always creates other ones.


Preliminary Investigation of the Impact of CAFO Manure Application on Water Quality
in the Portage River Water Shed

Dr. Robert Midden, Bowling Green State University

Concerns from citizens about the potential impact of CAFOs on water quality and an interest in providing real-world scientific research opportunities to undergraduate students led to this ongoing project in Wood County.  The initial project goal was to assess the impact of CAFO manure application on a portion of the Portage River Watershed, providing reliable scientific data to assist in management decisions regarding these and other related operations.  Additional long term goals included a long-term, comprehensive evaluation to identify the most significant practices impacting water quality for the entire watershed.  Sampling sites were selected to monitor drainage upstream and downstream of four CAFOs, two operational and two under construction, and adjacent to individual fields approved for manure application.  Data collected include E. coli, coliform, ammonia, nitrate, dissolved reactive phosphorus (DRP), pH, dissolved oxygen, electrical conductivity, water temperature, flow rate, GIS coordinates and some selected elements. 

More than 575 samples have been collected and analyzed since the project began in 2006 providing baseline data samples and a limited number of samples after manure application.  Paired samples were collected upstream and downstream of fields known to receive manure and were collected within one hour of each other and under a broad range of weather conditions.  The concentration of E. coli in upstream samples compared to downstream ones indicated no statistically significant difference with similar results for ammonia, nitrate and DRP concentrations.  Analysis of data from samples collected only after rain events indicated a larger numerical difference between upstream and downstream samples for E. coli, but it was not statistically significant.  However, as minimal data were available as to when manure was applied relative to sampling dates, the results are not conclusive regarding the lack of impact of manure application.  Some manure applications have been reported during the past 18 months and testing following these events indicated no impact under dry conditions.  In once case, data collected after a 2-inch rain event that occurred within 12 hours of manure application, indicated an increase of E. coli levels downstream, with higher levels of ammonia upstream.  Sampling 3 days later indicated no differences between upstream and downstream E. coli concentrations or other nutrients were evident.  However, these data are not statistically significant due to the limited number of samples.

The study has also identified attenuation in E. coli concentrations where water flows slowly through a portion of the stream with rich aquatic vegetation; however, the same reduction was not seen for DRP levels.  Testing for a number of elements was conducted using ICP atomic emission spectroscopy on one day and the low levels indicated that there did not appear to be any elevated levels of concern, however additional sampling is needed.   Additional data, including manure application timing and rates, soil tests and water samples, are needed to understand the variables that may affect water quality as well as the duration and real extent of the impact.  The research team is seeking collaboration from livestock and crop farmers, research institutions, and others interested in obtaining scientifically sound information.

To view the entire presentation, click here.

To view the presentation slides, click here.

John Smith (OSU): How many cows are located at each CAFO in the study area?  Midden:  One has approximately 790, the other 1400.

Smith:   What is the cost of DNA sequencing analysis used to identify sources of microbial contamination?  Midden: Approximately $500 per sample, including technician’s time.  Although, the data may be useful, analysis was limited due to lack of funds.

Kevin Elder (ODA):  For the DRP samples, was the water filtered in stream or in the lab?  Midden:  In the lab.  Elder:  There is an ongoing discussion/dispute as to which filtration method gives the most accurate results.

Andy Ety (ODA):  Is any information available regarding application of commercial fertilizers?  Midden:  No.  As data was collected between early March and late November, it would be helpful to know dates of both commercial and manure nutrient applications.  However, commercial fertilizer should not increase E. coli levels.  Ety:  Ideally, a controlled study with adjacent plots, one with manure and one with commercial fertilizer, would be conducted.  Midden:  Yes.  Also, we would like to know the impact of municipal waste water treatment facilities, septic systems and other human practices.  Additional collaborators and funding are needed to further the study.

Mike Monnin (USDA-NRCS):  Do you have soil test data that document phosphorus levels?  Midden:  It has not been available, but it would be helpful.  Increased local participation is encouraged to provide additional information.

Ety:  Have the area livestock producers and crop farmers who accept manure nutrients been invited to attend meetings with the Northwest Ohio Water Quality Working Group?  That could be a good way to increase participation of the local farm community.  Midden:  Not in the past, but it is a good idea.

Kathy Alexander (Ohio EPA):  It would also be helpful to sample total dissolved solids as clear water increases pathogen kill due to increased exposure to sunlight.  Midden:  We have begun measuring turbidity.  Also, the OARDC weather station that is nearby measures sunlight intensity.

Mark Fritz (ODA):  From what State of Ohio funding source was the $200,000 received?  Midden:  It was from the capital expense fund as a line item appropriation.

Nate Andre (producer):  Could the high E. coli levels detected on June 19 following the 2-inch rain that occurred 12 hours after spreading manure be attributed to cows or humans?  Midden:  No.  The source of the E. coli could not be determined as there was no DNA analysis.  However, there was no evidence of household septic in the area of detection.  Sampling in other areas of the study has been conducted where household septic is present and there is evidence that it is a source of E. coli contamination.

Fritz:  What is the impact of septic systems on E. coli concentrations?  Midden:  A septic discharge raised E. coli levels from 150 MPN/100 ml upstream to >242,000 MPN/100 ml at one location.  In this case, the concentration was reduced to 150 MPN/100 ml 250 meters downstream, in part due to dilution and in part due to attenuation as it traveled slowly through an area of high aquatic vegetation.   Note:  In the area where a rise in E. coli level was attributed to manure (June 19 event), it increased from 1,968 MPN/100 ml upstream to >24,200 MPN/100 ml throughout the site.  Three days after the rain event, levels had decreased to 239 upstream and 396, 1754, 380 and 515 MPN/100 ml adjacent to the field. (MPN/100 ml – Maximum Probable Number per 100 mililiters)

 [Note from Dr. Midden regarding analysis:  Most of our samples for E. coli  are split and one sample is tested without dilution and the other sample is tested with 1:10 dilution with buffer. The limit of detection for the undiluted sample is 2420 MPN/100 ml and the limit for the 1:10 diluted sample is 24,200 MPN/100 ml. In a just a few cases when we suspected that E. coli contamination level would be exceptionally high, in addition to the undiluted and 1:10 dilution we also performed a 1:100 dilution. That extended our limit to 242,000. But there was only one case that I mentioned in my presentation for which we had performed a 1:100 dilution analysis.]

Fritz:  Is the increase in the E.coli levels statistically significant?  Midden:  As only duplicate samples exist, there is not enough data to conduct statistical analysis.  Although there appears to be an impact, more research is needed before an accurate conclusion can be made.

Elder:  Was the field where manure was applied on June 19 systematically tile drained?  If so, was the manure incorporated.  Midden:  It was tile drained and the manure was injected into the soil.  Elder:  That information is critical and may explain why E. coli levels were elevated but nutrients were not.  Studies have shown that E. coli exposed to sunlight are killed, whereas when injected into the ground they are not exposed and can survive.  On the other hand, nutrients injected into the soil are less likely to be mobile, especially phosphorus which has low solubility.  Midden: Upstream nutrient levels may have masked nutrient runoff from the field.  Conclusions cannot be drawn without additional research.

Notes by Mary Wicks


Evaluating the Effectiveness of Compost Bedded Dairy Pack Systems for Ohio
Dr. Lingying Zhao, Ohio State University

The compost bedded dairy pack (BDP) system features loose housing with 3-4 feet of sawdust bedding that is stirred twice daily.  Although studies from Minnesota farms indicate the system provides good cow health and comfort and is easy to manage, the design and management parameters had not been evaluated for Ohio, where weather and geographic conditions are significantly different from Minnesota.  A scientific study was designed to meet the following objectives: 1) Analyze UMN’s recommendations to determine if they meet animal needs and can be applied in Ohio’s climate; 2) Evaluate BDP systems in Ohio to document practices and assess effectiveness; and 3) Develop recommended design and management guideline for BDP systems in Ohio.  Four study farms were selected for the study to represent various management practices.  The farms were visited in each of the four seasons to collect on-site indoor environment and air quality data (temperature, relative humidity, CO2, H2S, NH3),  pack samples for temperature, oxygen measurement and laboratory nutrient analysis (Total-N, NH3-N, ash, moisture, carbon, pH), and information or documents  for  management practices. 

The air quality in the dairy barns were well below the indoor air quality standards of OSHA (the Occupational Safety and Health Administration) for human health and the bedded pack data indicated composting was occurring but at a slower rate than at a commercial site.  The study concluded that UMN recommendations are effective for BDP barns in Ohio, including 65-90 sq ft/cow; 3-4 ft fine, dry sawdust with 1- to 2-inch additions every 10-12 days; stir the top 10-12 inches of the pack twice daily; 14- to 16-ft side curtains with fans for summer months;  scrape manure from feed ally twice daily and storing it separately; and total clean out every 6-12 months.  As sawdust can be difficult to obtain and expensive, especially during the winter, it was recommended that sawdust be stockpiled.  Straw may be used as an alternative but it should be chopped, alternated with sawdust additions, and turned twice daily.  For farms with cows on pasture during warmer months, the frequency of bedding additions, stirring, and scraping should be reduced.

To view presentations slides, click here.

Fred Michel (OSU):  How much manure is deposited in the feed alley?  Mary Wicks (OSU):  No volumes were measured or calculated.  The manure is scraped to a storage area twice daily, so measurement is difficult.  Calculation would require estimating how long the cows are in the alley and the volume of manure/cow deposited in the alley, thus would have high degree of uncertainty. 

Michel:  What is the cost of the sawdust?  Zhao:  The costs were not documented.  For a DBP farms to be viable, the availability and cost of sawdust should be evaluated.  Michel:  The conversion of one or more Ohio coal burning power plants to include biomass, has significantly increased demand for sawdust and other wood processing residues.  Alternative bedding sources are needed for long term viability.  (Note:  University of Minnesota has evaluated some alternative bedding, click here.)   

Michel estimated the sawdust cost at approximately $150/cow/year (360 cu ft/cow/yr at $10/cu yd).  Zhao noted initial construction costs for the compost bedded pack systems were less than traditional tie- or free-stall as no stalls are required.  Also, costs associated with daily management of the pack are minimal as the stirring is done using existing farm equipment, such as a cultivator, and requires only 15 minutes, twice daily.

Notes by Mary Wicks


Ohio Lake Erie Phosphorus Task Force
Kevin Elder, ODA-Livestock Environmental Permitting Program

After approximately 23 years of decreasing levels of dissolved reactive phosphorus (DRP) in Lake Erie, data collected by Heidelberg College began to show a significant increase beginning in the mid-90’s with a peak concentration in 2007.  In response, the Ohio EPA initiated the Phosphorus (P) Task Force, which includes representatives from industry, academia and public agencies, to assess possible point and non-point sources of P, changes in nutrient management practices, impacts from invasive species and other factors that could be contributing to increased DRP levels and impacting water quality.  Changes in nutrient inputs, including point sources, such as waste water treatment, home septic and industrial, and non-point sources, such as agricultural, urban and residential, as well as in-lake sources were evaluated.  Current problems are different than in the 1960’s, reflecting changes in nutrient cycling which have been impacted by changes in aquatic species, algal species, pH, temperature and oxygen levels.  Contributions of Total P (TP) are estimated at 796 metric tons/yr from point sources and an average of 6,000 metric tons/yr from non-point sources, although the latter are heavily dependent on the timing, frequency and intensity of storms.  P sources are also affected by land use.  In the western part of the basin, 50-80% of the land is used for row crops whereas land use in the central portion is primarily urban and forests.  Fertilizer sources of phosphorus are comprised of chemical fertilizers (66%), manure (27%) and biosolids (7%).   Runoff concentrations from a rain event within 24 hours of applying 100 lbs P2O5 indicating higher levels from fertilizer compared to manure, ~23 mg TP/l and ~7 mg TP/l for chemical fertilizers and dairy manure, respectively. 

Recommendations from the Task Force include educating producers on the need for soil tests, including frequency, sampling procedures, record keeping, utilization of test results, and calibration of application equipment.   In addition, practices such as filter areas along streams and ditches, incorporation of nutrients, precision technologies need to be encouraged.  Additional research is needed to evaluate the best method to measure dissolved P movement potential, identify critical environmental soil test levels, understand practices to minimize movement of dissolved nutrients, and determine best management practices to mitigate the potential for nutrient removal off the field.

To view presentation, click here.
To view presentation slides only, click here.

? from Columbus:  Where did the target goal of 11,000 metric tons/yr of P come from?  Elder:  Lake Erie Management Plan, which was a consortium of representatives from the U.S. and Canada.  The target was based on the best knowledge at that time and was focused on Total P;  however, while TP has decreased, DRP has increased.

? from Columbus:  Has the nitrogen to phosphorus ratio changed?  Elder:  That is considered part of the trigger for algae growth and needs to be studied further.  The same issue is being addressed in response to hypoxia in the Gulf of Mexico at the mouth of the Mississippi River.  There is data on the N:P ratios in tributaries but not for the lake itself.

Amanda Meddles (OSU):  What is the difference between TP and DRP?  Elder:  TP includes particulate, sediment bound P.  In the 70’s and 80’s most of the P load was in particulate form.  Dr. Terry Logan, OSU, surmised in the 80’s that with no-till practices increasing, TP would decrease but dissolved P would increase, in part due to decomposition of plant residues.  However, the level of change is greater than expected.

Harold Keener (OSU):  Do you see a change in P application rates on farms?  Elder: One of the research questions that came out of the study is to determine the effect of timing and method of application, e.g., incorporation or injection.  Also, the study supports recommendations such as not applying nutrients to snow-covered ground, applying amount needed, and using strip tillage.  Additional recommendations are in the report.

Robert Midden (BGSU):  Does the report indicate that the primary cause of increased DRP is increased adoption of no-till practices?  Elder:  Not necessarily.  Larger application equipment and changes in application timing, which is affected by larger fields, also play a role.  Additional research is needed.

Midden:  How much of the DRP is estimated to come from ag sources?  Elder:  It’s not easy to determine because of the complexity associated with storms and runoff curves.  There is an increased volume of river discharge to the lake since 1995 which affects runoff of nutrients.  Additional research is needed.

David Munn (OSU):  Could dissolution of P in sediments accumulated at the bottom of the lake 50-75 years ago be contributing to DRP levels?  Elder:  A few years ago we would have thought it possible, but the lake recovered in the 80’s even though sediments high in nutrients had accumulated on the lake bed.   The current increase in algae is also increasing affecting nutrient cycling as it causes a decrease oxygen levels and other changes.  We need to understand what reduction in P is needed to stop the algae bloom cycle.  In the last 40 years, species of algae and other aquatic species have changed, so more research is needed.  In the meantime, P from all sources needs to be reduced.  One outcome of the study is that all P will be removed from lawn fertilizers in Ohio as it is not needed.

? from Bowling Green:  With an increase in the number of CAFO’s in Northwest Ohio, greater volumes of liquid manure are being applied to cropland.  Why does the ODA use an application rate of 50 ppm P?  Elder:   ODA is following current NRCS standards and research coming from OSU, ISU and MSU. The 50 ppm is an agronomic level based on crop needs but is not an environmental level.  The environmental recommendation is based on soil test levels with a cut off of 150 ppm P or on site assessment level that evaluates the distance to water resources and type/method of application.   The task force has recommended reviewing agronomic levels.

Notes by Mary Wicks