The September NEPC newsletter (PDF) has information on the 2015 annual meeting, grazing management, the bluegrass billbug and more.
Our annual conference and meeting in 2015 will be at the Waterfront Place Hotel and the Greater Morgantown Conference & Convention Center on March 11-12 in Morgantown, WV. It precedes the Appalachian Grazing Conference held on March 13-14 at the very same location. The Waterfront Place Hotel and Conference Center is located at Two Waterfront Place 3 miles from the West Virginia University Ag. Sciences Building. It is hoped that the later date will avoid the bad weather that we have endured the past two years.
Your Executive Committee has selected these topics for the 2015 conference: Riparian Pasture Literature Review Results & Discussion; Orchardgrass Die-off, Possible Causes and Preliminary Findings; Progress of the “Assisting Organic Dairy Producers to Meet the Demands of New and Emerging Milk Markets” Research Project; Results of Energy Audits on Grazing Farms in the Northeast; and Dung Beetle Usefulness and Protection in Pastures. The registration form and detailed agenda will be available soon.
Carbon Sequestration Potential of Agricultural Systems
R. Howard Skinner USDA-ARS, University Park, PA
Through proper management, agricultural systems (cropland, pasture, and forest) have the ability to remove carbon dioxide from the atmosphere and sequester it in soils and wood products. The carbon thus sequestered can help slow the increase in atmospheric carbon dioxide currently occurring as a result of burning fossil fuels, and could help reduce the potential impacts of future global warming. Several entities, both national and international, are now, or in the future will offer payments for sequestered carbon. This poster presents results from an extensive literature review comparing the carbon sequestration potential of various agricultural systems including conventional and reduced tillage row crops, pastures and native grasslands, and forested lands. Globally, terrestrial ecosystems sequester 100 to 300 kg C/ha/yr (90 to 270 lbs C/acre/yr). Sequestration rates on individual farms can be much higher, but they can also be negative under some management practices and climatic conditions. Agricultural carbon sequestration could offset about 15% of current fossil fuel emission but perhaps only 5% or less of future emissions.
An extensive review of the literature examined 68 published articles ranging from studies of individual sites to global estimates of ecosystem carbon sequestration potential. Three primary types of analyses were included:
- use of soil cores to directly meaure changes in soil carbon over time;
- micrometeorological and survey methods that track individual C inputs and outputs;
- model simulations.
Studies are mostly from the United States and Europe. Results are presented in lbs C/acre/year. To convert from C to CO2 multiply by 3.7.
Croplands under conventional tillage are generally considered to be net sources of C to the atmosphere. No-till practices have been thought to increase C sequestration but recent studies cast doubt on that conclusion due to issues with soil sampling depth. Carbon losses under conventional tillage are small, about 400 lbs C/acre/yr. No-till practice might reduce C loss by half. Variability among and within studies is huge, with the difference between no-till and conventional ranging from –6000 to 4400 lbs C/acre/yr. In corn/soybean rotations, C tends to accumulate during corn years but is lost under soybean. Limited information is available comparing organic vs. conventional agriculture, but organic systems appear to sequester about 1000 lbs C/acre/yr more than conventional systems.
On average, grasslands sequester about 250 lbs C/acre/yr. Conversion from row crops to pasture can result in net C gain of about 650 lbs C/acre/yr. Mature pastures sequester less C than young pastures and can sometimes become C sources to the atmosphere. Results from various grassland studies range from a loss of 2250 lbs C/acre/yr to a gain of 3800 lbs C/acre/yr. Limited information suggests that rotational grazing can increase sequestration compared with continuous grazing, and that moderate N fertilizer rates can increase sequestration compared to either very low or very high fertility sites.
Forests differ from crop and grasslands in that most C is sequestered aboveground. Carbon is sequestered at higher rates than in agricultural soils but is also susceptible to rapid loss from fire and other disturbances. On average forests sequester about 1200 lbs C/acre/year with a range from –1500 to 6000 lbs/acre/yr. Forests tend to lose C for the first few years following clear cutting, but, in some cases, can sequester C for hundreds of years thereafter.
North American wetlands, including peatlands, freshwater mineral soils, estuaries, and tidal marshes sequester 1500 lbs C/acre/yr, with individual ecosystems ranging from 150 to 3000 lbs C/acre/yr. These are some of the most productive systems for C sequestration on the continent.
From researchers at the University of New Hampshire (for information; this is not a NEPC-sponsored project):
We are looking for participants for an upcoming study at the University of New Hampshire related to the conversion of forest to pasture.
We have found that there are quite a few farmers locally who are interested in converting woodland to pasture in the form of silvopasture. There isn’t a lot of information available about the effects of different conversion strategies (i.e. total clearing to pasture, or thinning to silvopasture), and we are interested in looking at the impacts of those different strategies in terms of ecosystem services.
We are looking for participants located in central/southern New Hampshire, central/southern Maine, or central/southern Vermont. If you are thinking about converting forest on your property to pasture and are interested in participating, please e-mail Alix Contosta at alix (dot) contosta (at) unh (dot) edu for more details. In your e-mail, please:
1) Tell us where you are located
2) Provide a brief description of the acreage and intended management plan (for example, converting to open pasture or converting to silvopasture)
3) Put ‘Pasture study’ in the subject line.
Case Study: Dairies Using Ultra-high Stocking Density Grazing in New York and Pennsylvania
Dr. Kathy Soder, USDA-ARS Pasture Systems and Watershed Management Research Unit, University Park, PA
Ultra-high stocking density (UHSD) grazing, sometimes referred to as “mob grazing”, is characterized by:
- high stocking density (units bodyweight/units area 500,000 + lb/ac)
- small paddock size
- mature forage
- short grazing durations
- long forage recovery times (90 to 180 days)
Some perceived benefits include:
- increased profitability (via increased carrying capacity)
- improved animal performance
- improved forage species diversity
- increased soil quality (improved organic matter, improved microbial action, and greater water holding capacity)
Ultra-high stocking density grazing was developed using beef cattle, often in arid rangeland environments. Little science-based evidence exists about the application of this grazing management practice on dairy farms in the northeastern U.S.
The Case Study
Four farms (3 in PA and 1 in NY) participated in this study. All dairy farmers were self-described UHSD graziers, with 15+ years of grazing experience. Farmers were initially surveyed to capture experience and management practices.
In June 2012, one representative pasture on each farm was identified to be study pasture. Farm visits to collect data occurred each time the study pastures were grazed from June to November of 2012 and from April to June of 2013. During each farm visit, researchers collected information about the number of cows grazing, pre- and post-grazed forage height, pre-grazed canopy stratification, and forage samples for forage quality analysis. In May of 2013 soil samples were collected from each study pasture.
- Stocking densities were lower (44,091 to 337,161 lb/ac; Table 1) than UHSD grazing with beef cattle (500,000+ lbs/ac).
- Pastures were rested longer (30 to 49 days) than usually seen with rotational grazing (21 day cycle).
- Pastures were grazed taller (8 to 17 inches) than usually seen with rotational grazing (6 to 8 inches).
- Forage utilization = 45% of total available dry matter.
- Most forage consumption was from the upper canopy.
- Forage quality was high throughout the season
- Soil organic matter values (3.2 to 4.1 %) were as expected, but did not exceed values typical for this region.
The dairies in this study have taken a modified approach to current UHSD definitions by grazing slightly more mature (taller) forages and implementing slightly longer periods of forage rest, compared to rotational grazing.
UHSD grazing with beef cattle allows for more mature forage within a production system that is more forgiving on a daily basis (ADG) compared to a dairy system. Grazing forages that are too mature could result in an overestimation of nutrient availability and intake for lactating dairy cows, resulting in reduced animal production immediately reflected in the bulk tank.
Grazing dairy farmers who are interested in adopting UHSD grazing should proceed by taking small steps and allowing the system (animals, forages, soils) to respond before making further grazing management modifications.
This was a collaborative project between USDA-ARS and Penn State Extension. Funding was provided by Northeast SARE grant #PG12-021.
Dear Orchardgrass Task Force, Extension agents, Professors, Industry members, and others,
I am a PhD student in Crop and Soil Environmental Sciences at Virginia Tech. I am working with Dr. Ben Tracy on understanding the causes of reduced persistence in orchardgrass hay stands around the region.
One component of my work is to survey orchardgrass stands in the hay-growing regions of Virginia, West Virginia, Maryland and Pennsylvania (See attached map). I would like to ask your help in finding orchardgrass stands to include in the survey.
It is my hope to be able to sample 30 to 50 fields across this region during and around my spring break, March 7-16. I will collect plant and soil samples, assess stand cover, and scout for insects and diseases. I will revisit these stands in August 2014, March 2015, and August 2015 to assess persistence. With a little bit of information from producers about their management practices, this survey should help to identify agronomic and ecological factors related to reduced orchardgrass persistence.
Right now, I’d like to generate a list of potential stands to include in the survey and collect some information from their producers. There are a variety of logistical challenges in terms a large area to cover in a short window of time, so I may not be able to visited every field submitted.
To be a good candidate for the survey, an orchardgrass field should:
- Be approximately within the region marked on the attached map.
- Contain 50% or more orchardgrass.
- Be approximately 2 – 5 years old.
- If possible, be located on a farm where some OG stands are in good condition and others poor – farms where are I can sample paired fields like this are especially valuable.
If you know producers with stands that meet these criteria, please:
- Work with the producer to fill out the attached one-page Stand Description sheet and return it to me. Please use one sheet per orchardgrass stand; multiple sheets per producers are encouraged.
- Provide me the exact location of this field. Three ways of doing this are to: send me latitude and longitude of the field, email me a Google Earth placemark, or send a NRCS soil map with the field outline.
Attached is a sample field submission.
With a list of potential fields, I will determine the route I’ll take between them and contact producers with when I’d like to visit their stands. This will be in early March, and I will not need any assistance from the producers during the actual sampling.
Please send me stand information by February 28.
I very much appreciate your help with this. Please do not hesitate to contact me with any questions or issues. Feel free to share this email with whoever may be interested.
I’m quite interested to see what the survey turns up and hopefully be able to provide some recommendations to improve orchardgrass persistence.
Gordon B. Jones
Doctoral Degree Student
Crop & Soil Environmental Sciences
Central New York RC&D has prepared the 2014 version of its grazing monitoring charts. These and other resources are available at their website.
Grazing few hours during the afternoon and evening
Dr. Kathy Soder, USDA ARS Pasture Systems and Watershed Management Research Unit
- Cattle concentrate grazing during the afternoon and evening.
- Pasture presents the highest sugar, digestibility and less fiber concentrations in the afternoon and evening.
- Afternoon pasture allocations increases duration and intensity of afternoonevening meals and pasture intake at that time of day, improving animal performance.
- Pasture intake rate is increase with “hunger”, therefore pasture intake during the afternoon-evening may not yet be maximized.
These facts led an Argentinean research team A planned morning fasting generates (National University of La Plata) to assess the impact of morning fasting periods combined with afternoon pasture allocations on grazing behavior, pasture intake and performance of beef heifers.
When heifers were fasted:
- Grazing time during afternoon-evening hours increased.
- Idling increased and was concentrated during the morning.
- Performance and pasture intake were not affected.
A planned morning fasting generates longer, more intense afternoon-evening meals, increasing the intake of higher nutritive pasture, resulting in equal cattle performance with shorter grazing periods.
This management reduce residence time on pasture; therefore reducing injuries to plants and soil compaction. Consequently, this management would enable northeastern US graziers to improve future pasture production.
Pasture Seed Banks
Dr. Matt Sanderson, USDA ARS Pasture Systems and Watershed Management Research Unit
What is a Seed Bank?
It is a reserve of dormant seeds in the soil that enables some types of plants to re-establish themselves after a drastic disturbance of the established vegetation. In some ways it forms a “memory” for the pasture, a record of its vegetation history.
What Types of Plants Occur in Seed Banks of Northeastern Pastures?
In our surveys of northeastern pastures, we found the equivalent of more than 8 million seeds per acre in the surface soil (the top four inches) from the seed bank study. These seeds came from 58 species of plants. Seed bank composition of northeastern pastures
The annual forbs (all broadleaf plants with the exception of legumes and trees) dominated the seed bank with more than 4 million seeds per acre in the top four inches of soil. This class of plants included mainly weeds such as yellow rocket, lambsquarter, mustard, and shepherd’s purse. Dandelion and broadleaf plantain contributed most of the 1.2 million seeds per acre of perennial forbs in the seed bank.
Green and yellow foxtail along with annual bluegrass and barnyard grass dominated the 1 million seeds per acre we found of the annual grasses. Kentucky bluegrass was the most abundant perennial grass seed found in pasture soils, equivalent to about l lb of seed per acre.
White clover contributed to about 1 to 2 lbs of seed per acre in the legume component of the seed bank. Thus, in the northeastern U.S., bluegrass and white clover will supply most of the forages in the seed bank that may contribute to maintaining a pasture stand.
Even though most of the seeds in the soil seed bank were annual forbs, the plants growing above ground were nearly all bluegrass and white clover. There was only a 44% correspondence between the plant species found in seeds below ground and the plants found growing aboveground. Thus, you cannot exactly know what is in the soil seed bank by looking at what is growing in the pasture.
The plant species found in pasture seed banks fall into four main categories
The first type of seed bank is a short-term (usually lasting less than one year) seed bank formed from plants that shed seed in the summer, germinate in the fall, and grow mainly in the early spring of the following year. These plants fill in gaps, holes, or bad spots in pastures that predictably occur in fall, winter, and early spring.
The second type of seed bank is also short-term but the plants that contribute to this seed bank shed their seed in the fall, germinate the following spring, and make most of their growth in late spring and summer. These are the summer-annual plants such as common ragweed, the foxtails, and crabgrass. These plants fill in pasture gaps that predictably occur in late spring and autumn.
The third and fourth types of seed banks are both longterm seed banks that differ in how much of each seed germinates right away and how much remains dormant. For example, the bluegrasses and bentgrasses produce a lot of seeds, most of which germinate quickly and the small remainder stay dormant and persist in the soil On the other hand, hard-seeded legumes such as white clover do not germinate right away. Instead their hard seed coat and seed dormancy ensure that the bulk of seeds persist for a long time in the soil.
How can a Farmer Draw Upon the Seed Bank for Pasture Management?
There are three main items to focus on. First, a supply of seeds must be present from desirable plant species. Remember, in our survey, the most abundant supply of forage seeds came from Kentucky bluegrass and white clover (about 1 to 2 lb per acre of each). Thus, forage in pastures developing mainly from the soil seed bank will be mostly bluegrass and white clover. Second, seeds from undesirable species (weeds) must be absent or few. Unfortunately, these types of plants dominated that pasture seed bank in our surveys. This means that producers must emphasize the third item, maintain suitable conditions for the germination, establishment, and maintenance of the desired forage species. In other words, producers need to do the right things to foster the desirable species including maintaining optimal soil pH (6.0 to 7.0) and fertility levels (especially phosphorus for legumes) along with appropriate grazing and clipping management to control weed growth and encourage forage growth.
The large number of weedy seeds in the pasture seed bank means that any gaps or bare spots in the sod will likely be filled by a weed from the seed bank. If not controlled, these weeds can contribute more seeds to the seed bank in a vicious cycle of weed invasion. Thus, maintaining a dense, vigorous pasture is critical.
Using a total mixed ration on a pasture-based dairy
Dr. Kathy Soder, USDA ARS Pasture Systems and Watershed Management Research Unit
Feeding dairy cows on pasture challenges nutritionists and producers due to changing pasture quality and availability which make dry matter intake (DMI) difficult to monitor and control. Milk yield per cow and milk fat percentages in pasture-based systems are frequently lower than in confinement. Some producers are using a ‘hybrid’ approach- many dairy producers have the knowledge and equipment for total mixed ration (TMR) feeding systems and have incorporated a “partial” TMR (pTMR- partial since the pasture is not physically part of the mixed ration) into their summer grazing management.
Why Feed a pTMR with Pasture?
Increasing numbers of dairy producers in the northeastern and midwestern US are using or have expressed interest in using a pTMR with their grazing dairy cows to maintain or improve milk production and composition, particularly as herd size increases with the land base remaining constant. Few recommendations exist regarding the use of a pTMR. Therefore, we rely on basic ration balancing methods and practical experience for developing feeding recommendations.
A pTMR incorporated into a pasture-based diet provides
the advantages of:
- A more uniform ration throughout the grazing season
- Improved monitoring of DMI
- Less chance of rumen digestive problems due to slug feeding of grain
- Potentially higher milk yield and components
- Environmental benefits due to better utilization of nutrients.
- Higher energy intake and body condition.
Formulating a pTMR
Balancing a ration for cows on pasture is the same as formulating a ration for confined cows. Pasture is simply an ingredient that is not mixed in the mixer wagonrather, it is mixed in the rumen with the other pTMR ingredients. Since pasture quality can vary widely, Forage Testing of pasture as well as the pTMR is crucial in balancing the diet.
While this may seem an obvious statement, in a case study conducted at our location that monitored pTMR use on 13 farms in PA and NY, we found that some producers and nutritionists are not fully aware of the nutritional quality of pasture. In our study, the most common change in the pTMR was to replace pasture for grass silage on a 1:1 DM basis since grass silage most closely matches pasture in terms of nutrient content of any pTMR ingredient.
The second most common change was to reduce the protein level in the pTMR, usually through reducing or eliminating protein supplementation to compensate for the typically high rumen degradable protein levels in well-managed pastures. Other changes may include the addition of other fiber (forage or non-forage) sources to compensate for low pasture fiber, particularly during the spring season. Other farms, however, were found to be overfeeding protein, particularly rumen degradable protein. Not only does this waste money, it causes greater nitrogen losses in urine.
Is Feeding Pasture Plus TMR Economical?
Research at our location, using a whole-farm simulation model, showed that utilizing a pasture plus pTMR was comparable economically to feeding a TMR in confinement, and both TMR systems increased net return per cow by an average of $260 annually when compared to pasture plus concentrate. In addition, the pasture plus pTMR provided environmental advantages in terms of lower phosphorus and potassium accumulation when compared to the confinement system.
How Much pTMR Should I Feed?
The amount of pTMR fed will depend on the cows’ requirements, pasture quality and quantity, and land availability. While there are no set guidelines for minimum amount of forage to include in a pTMR, a minimum of 6-7 lb. of forage dry matter per cow is recommended to serve as:
- A source of effective fiber (to promote cud chewing)
- A rumen buffer
- A carrier for other components in the pTMR
As pasture quantity decreases, the amount of forage in the pTMR can be increased to meet this deficiency.
When to Feed a pTMR?
Timing of pTMR feeding in relation to milking and grazing may affect intake of both TMR and pasture. Feeding a pTMR before cows graze will encourage greater pTMR consumption but it may lower pasture intake. A pTMR may also provide better synchronization of nutrients in the rumen; energy and effective fiber in the pTMR and protein in the pasture. Alternatively, offering pTMR after an initial period of grazing may decrease pTMR intake and maximize pasture utilization.
Guidelines for Feeding a pTMR
While pTMR can be used to complement pasture and provide a balanced ration, pasture variables such as pasture DMI, quality and quantity, and selective grazing behavior still challenge nutritionists and producers. These management practices below can help to effectively incorporate a pTMR in a pasture-based system.
- Provide adequate feed bunk space Cows have a limited time to consume pTMR before returning to pasture. It is important to provide sufficient bunk space (25 to 30 inches/cow) so all cows have sufficient opportunity to consume the pTMR. This ensures that aggressive cows do not dominate the feed bunk by keeping more submissive cows from consuming their share of the pTMR.
- Including Corn Silage Corn silage in a pTMR can be an excellent supplemental forage as it adds rumen fermentable carbohydrates as a source of energy for the rumen microbes (to recapture the abundant pasture protein) and also ‘dilutes’ the high protein in pasture. Corn silage also adds effective fiber that can complement high-quality pastures. Corn silage is a highly palatable feed, an excellent carrier for supplemental grains, and may allow for a reduction of concentrate fed.
- Flexibility Many farms in the case study were flexible in pTMR formulation, reacting quickly to perceived changes in pasture quality or quantity. Flexibility is key in utilizing a pTMR on pasture-based operations- flexibility in ingredients used in a pTMR to keep costs low, to meet nutrient demands, to maintain satisfactory milk production and milk components, and flexibility on the part of producers and nutritionists in reacting to changes in environment, pasture quality and quantity, feed prices, and animals.