STUDY PROPOSAL
Idaho ranks first nationally and accounts for 50% of the USA Kentucky bluegrass
seed production. In 1999, Idaho produced 16.3 million kg of bluegrass seed valued at
$45 million from 24,300 ha. Established bluegrass stands prevent erosion and nutrient
loss to surface water, protecting soil and water quality. Sustained bluegrass seed
productivity historically has relied on open-field burning of post-harvest residues that has
been associated with significant air quality issues and public health impacts. Mandatory
regulations that restrict burning of bluegrass fields in Idaho are anticipated. Alternative
management systems must be developed that eliminate or substantially reduce the need to
burn bluegrass residues yet sustain productivity and economical seed yield before
restrictions are imposed, otherwise the viability of this economically and environmentally
sound industry will be threatened severely. Residue management systems must be
developed and tested in long-term, large-scale, on-farm trials that represent typical
grower field conditions to properly assess treatment effectiveness on residue levels and
impacts on grass seed production. This includes appropriate agronomic, ecological,
environmental, economic, and sociological studies and analyses. Most alternatives to
field burning require increased dependence on farm implements, fossil fuels, and
herbicides, which are often associated with reduced grass seed yield. Integration of
ruminant livestock enterprises (beef cattle or sheep) with grass seed production
enterprises and/or use of emerging biotechnology alternatives for enhanced microbial in
situ residue decomposition offers potential alternatives to field burning of grass seed
residue that may sustain economic returns to the agricultural community.
Mechanical forces applied through ruminant animal utilization of grass seed
residue include disruption of the sod via hoof action and physical particle size reduction
via mastication during ingestion and rumination (feed particulate is commonly reduced to
less than eight mm for transit through the digestive tract). Grass seed residue is further
reduced via microbial fermentation in the rumen and other fermentative organs of the
hind gut. These mechanical and fermentative forces imposed by the ruminant animal
may be managed to have the same net effect as open- field burning of the crop residue.
Successful integration of the livestock and grass seed enterprises therefore, could serve to
eliminate air quality problems associated with grass seed burning while securing an
economic value from the grass seed residue
Numerous plant and animal interactions need to be qualified before feasible,
integrated systems can be adapted. Timing or season of grazing and grazing intensity or
utilization are factors that likely impact sod integrity and consequently sustainable grass
seed production. Critical to the understanding of a viable integrated production system
would be the evaluation of the nutrient content of the grazed or baled crop residue. Fall
and winter feed costs are commonly recognized as the largest operational expense for
cow-calf enterprises and usually distinguish a high profit from a low profit enterprise.
Grass seed residues would become available at the beginning of this critical grazing and
feeding period. The suitability of grass seed residues as a nutrient resource for either
mature, mid-gestation beef cows or fall-weaned calves (assuming protein and energy
supplementation are provided) have the potential of having a positive impact of the profit
potential of a cattle enterprise integrated with grass seed production.
When considering soil-plant systems, the presence of a litter layer is generally
desirable. In addition to the conservation of moisture and protection against raindrop
impaction and erosion (Stott et al., 1999), decomposition of the litter layer also serves as
a major pathway of nutrient addition to the soil system (Schlesinger, 1991). Kentucky
bluegrass requires a high N application rate. Currently N is often applied based on
potential yields and precipitation (Mahler and Ensign, 1989). Over-application of N
fertilizer may result in nitrate contamination of groundwater and represents an economic
loss to the grower. Leaving residues to decompose in the field ensures that some of the
nutrients taken from the soil by plants are recycled. The release of nutrients from the
residue should be considered when making fertilizer recommendations and may increase
sustainability by reducing the dependence on inorganic fertilizers.
Project objectives:
1. Develop livestock grazing systems and/or use of emerging biotechnology alternatives
that optimize biomass turnover and maintain or increase bluegrass seed yield without
burning.
2. Compare nutrient cycling efficiency in burned, mechanically managed and grazed
bluegrass systems.
3. Investigate above ground insect pest and predator relationships in each bluegrass
production system andmonitor diseases and weeds associated with the different
treatments.
4. Examine the economic efficiency of each bluegrass production system including the
associated production, price, and financial risk.
5. Identify potential key socio-cultural and economic costs and benefits of livestock
grazing management practices or biotechnology alternatives versus current open-burning
practices.
6. Distribute information to growers, field consultants, extension educators, and
scientific audiences.
Methods:
Objective 1 – A large-scale, long-term, on-farm experiment will be established in
a grower-cooperator (Tom Mosman) field in Lewis County, ID. All production
operations will be performed using field scale, grower provided equipment. The research
area will be about 15.7 ha. The experiment will consist of seven main post-harvest
residue removal treatments replicated four times [open field burn (current practice), bale
and burn, mechanical removal – bale + mow, and two levels of cattle grazing intensity
(high and moderate) at two grazing times (immediately after grass seed harvest and one
month after harvest)]. At least half of each plot will contain only main treatments, while
the other part will be used for smaller plot experiments (pest control and monitoring,
nutrient cycling, emerging microbial biotechnology alternatives, etc.). At least three
cycles of a system are necessary to determine the long-term effects of treatments. A
weather station will record air and soil temperatures, precipitation, relative humidity, and
total solar radiation. Panicle number, grass seed yield, 1,000 seed weight, and percent
seed germination are determined each year for each main and subplot treatment.
The plot area will have a secure perimeter fence and will be cross-fenced to
provide four uniformly sized blocks. Each block will be further cross-fenced and contain
four 0.8 ha grazing treatments and three 0.2 ha burn and mechanical residue removal
treatments. The fence will be arranged so that beef cattle assigned to each replicate will
have access to an available water source. Immediately after grass seed harvest, cattle
owned by the grower-cooperator will be assigned to specific grazing treatments. Cattle
will be excluded from the non-grazed treatments. Daily management of the cattle
(routine inspection, providing mineral supplement, checking available water, etc.) will be
the responsibility of the grower-cooperator. Periodic field inspections will be conducted
to visually evaluate degree of residue removal by the cattle and level of damage to the
bluegrass plants by grazing and hoof trodding. Based on these visual inspections, cattle
will be removed from moderately grazed plots when 50% of the biomass has been
removed.
Cattle will be allowed to graze the high intensity grazed plot until 90% of the
biomass is removed. These arbitrary levels of residue utilization and plant damage
(moderate and high) can be adjusted at the discretion of the grower-cooperator and the
county Extension educator. At the termination of each grazing treatment the amount of
residue biomass remaining will be determined. At the beginning and at the end of each
grazing period, weights of the cattle will be obtained on two consecutive days. Total
mega calories of metabolizable energy harvested will be determined based on body
weight and on weight gain or loss of the animals during the grazing period. An economic
value of the grazed residue will be estimated based on the fair-market value of mega
calories from locally produced conventional forages and grains. As an additional
appraisal of energy harvested by the cattle, an estimate of digestibility of the grazed
forage will be determined. Available forage (tillers plus residue) will be sampled along
with fecal samples from random droppings. Forage and fecal samples will be assayed for
an internal digestibility marker (such as indigestible acid detergent fiber) to determine
organic matter digestibility.
Objective 2 – The distribution of C, N, S, and P will be determined in plots where
aftermath is grazed immediately after seed harvest at the highest grazing intensity, field
burned, baled and burned, or mechanically removed. Soils will be sampled prior to the
applications of treatments to determine the initial soil properties. For each year of the
study, soil samples will be taken from each plot in the spring and again in the fall to
determine changes in nutrient levels. Total N, C, and S will be measured using a dry
combustion C/N/S analyzer. Inorganic (plant available) N will be determined by
extraction with KCl (Mulvaney 1996). Organic N will be determined by subtracting the
inorganic forms from the total N measured by the C/N/S analyzer. Available P will be
measured using the Bray-1 test (Kuo 1996), due to the acid nature of these soils.
Aboveground biomass will be measured periodically while the sites are snow-free
(approximately April through November) and decomposition rates will be calculated
(Stott et al. 1990). Straw biomass will be collected in each of the four treatments, dried,
weighed, and the total elemental composition determined. Straw will be burned in a
muffle furnace at 500°C for 24 hours to determine the ash-free weight. The C, N, and S
content will be determined by dry combustion.
The emerging microbial biotechnology subplot treatments will include bale plus
microbiologically enhanced field residue decomposition, and microbiologically enhanced
field residue decomposition following cattle grazing (for the moderate and high grazing
intensity treatments that are grazed immediately after harvest). The results for each of
the microbiological treatments will be compared to those of all other treatments (open
field burn, bale and burn, mechanical removal, and at each level of cattle grazing
intensity). A mixture of two compatible strains of naturally occurring, saprophytic,
nonpathogenic lignocellulose-degrading bacteria will be used. These actinomycetes,
Streptomyces hygroscopicus WYE53 and Streptomyces hygroscopicus YCED9 were
originally isolated as antifungal biological control and biological dethatch agents for use
in turf. They decompose highly resistant thatch and grassy residues while also inhibiting
the growth of plant pathogenic fungi (Chamberlain and Crawford 2000). A related strain,
Streptomyces lydicus WYEC108, is currently used commercially as an antifungal
biocontrol agent in turf and agricultural crops (Doumbou et al. 2002). All were isolated,
identified and characterized in Dr. Crawford’s laboratory. The strains are not pathogenic
to any plants or animals. They are classified as plant residue decomposers and plant
growth promoting rhizobacteria (PGPR) (Doumbou et al. 2002). Since they will be
applied as dry granular powders or dissolved in water, workers applying the product will
wear masks to prevent inhalation of powders or aerosols, simply to minimize chances of
inhaling dust/aerosols. Some people can become allergic to actinomycete spores/dust.
Microbial formulations will be applied within subplots immediately after baling
and mowing where residue is removed mechanically and to each of the cattle grazing
treatments immediately after cattle are removed. It is hypothesized that the soil
disruption caused by intensive cattle grazing will mix remaining residues into the surface
layers of the soil, which will significantly enhance their decomposition rate by the
actinomycetes. Formulations are dry powders containing dormant Streptomyces spores
(108-9 spores/gram) (Chamberlain and Crawford 2000). The carrier will be granular
zeolite (applied like a dry fertilizer) or whey (dissolved in water and applied as a liquid).
They are produced by growing cultures on agar media until they are well sporulated. The
spores are harvested and transferred aseptically to sterile carrier to the desired spore
count per gram. The application rate varies with residue levels (102-4 spores per cm2).
After application, the spores germinate and the microbes colonize and decompose the
grass residues present in and on the soil (Trejo-Estrada, et al. 1998). During growth, they
also kill or suppress the growth of fungal plant pathogens present within the residues
(Chamberlain and Crawford 2000; Trejo-Estrada et al. 1998).
The parameters monitored will include grass seed production, residue
decomposition rate/biomass turnover (includes measuring residue samples for relative
losses of cellulosic and lignin components from the residues over time), total microbial
and actinomycete counts, and the number of fungal propogules and pathogens. Plots will
be available to the other investigators for measurements (e.g., residue nutrient content,
suitability of residue as feed for cattle with differing nutrient requirements, nutrient
cycling measurements, pest/predator relationships, etc.).
Objective 3 – Treatments and controls will be monitored for pathogens via disease
surveys, and pathogens identified using standard morphological, physiological, and
genetic identification techniques. Weed infestations will be monitored and controlled as
needed.
Arthropods (including spiders), harvestman, carabid, and rove beetles, and
Collops spp., are sampled periodically during the season using pitfall traps and sweep-net
samples in each plot. Carabids are well known predators of slugs in cereal systems in
Europe (Ayre and Port 1996) and could be significant biological control agents for slugs
commonly found in grass seed fields (David Mosman, personal comm.). Slugs are
sampled periodically during the season using refuge traps (Bolton et al. 1996) to estimate
their relative abundance across treatments. This periodic survey of predators will help to
explain the relationships of the predators and slugs spatially and temporally.
Objective 4 – The economic analysis will assess the production, price, and
financial risk associated with each of the seven bluegrass production systems. Cost and
return (CAR) estimates will be developed for each system. Ownership costs will be
allocated over the productive life of the assets required for each system using established
capital recovery methods (AAEA 1998). A deterministic comparison of the profitability
of the seven production systems will be conducted using the CAR estimates, actual
bluegrass seed yield, straw and livestock production yields, and actual output prices. To
quantify production, price, and financial risk, a stochastic simulation model will be
developed using @RISK (Palisade 2000). The base model will be the seven bluegrass
enterprise budgets obtained from the CAR estimates. Empirical probability distributions
for seed and straw and livestock yields, will be incorporated into the model to account for
production risk. Historical bluegrass seed and livestock prices will be obtained, and
cyclical and long-term trends will be modeled using harmonic regression technique tools
(Van Tassell et al. 1989). Residuals from these trends will be modeled and simulated to
account for price risk from bluegrass seed and livestock prices. A planning horizon
covering estimated bluegrass stand life under each production system will be used in the
stochastic simulation. The model will be simulated for 1,000 iterations. Random draws
from each price and yield distribution will be obtained each year of the simulation while
maintaining historical correlations (Palisade 2000). The appropriate yields from each
system, along with input and output prices, will be used to determine yearly income and
cash flow. The net present value of each system will be determined by summing the
present values of the yearly income streams for each iteration. Net present values will be
compared using stochastic dominance techniques (Hardaker et al. 1997). Differences in
net present values and other key economic indicators will also be examined using
appropriate t-statistics and chi-square statistics.
Objective 5 – An assessment in changes to lifestyle, production, and technology on
the farm will be determined. Sociocultural factors impact resource use and decisionmaking and management practices (Butler and Carkner 2001). Multiple cycles also will
allow for longitudinal assessment of social change that may accompany technology
adoption patterns and production changes. Understanding these types of social dimensions
is critical for determining the overall success and implementation of change, adaptation,
and evolution to alternative systems.
Objective 6 – A web site will be constructed and maintained. Information will be
distributed to growers, field consultants, and the general public via extension field tours
and presentations by county extension educators and scientists. Activities include field
tours (annual Lewis County extension crop tours and special half-day field tours at
critical phases of the research (e.g., fall grazing and prior to grass seed harvest) and
presentations (winter extension meetings put on by field consultants and/or county
extension educators). Publications include popular news articles and extension bulletins.
Findings also will be presented to scientific audiences in refereed publications (Weed
Technology, Soil Science, Journal of Applied Seed Production, Journal of Animal
Science, etc.) and presentations (regional and national professional meetings).
Producer involvement:
A Kentucky bluegrass team currently is in place at the University of Idaho and
consists of grass seed growers and livestock producers; research scientists from different
discipline areas; extension specialist or county faculty; and representatives from local
Indian tribes, the Idaho Department of Environmental Quality, and the USA EPA.
Producers, some of whom are field research collaborators, provide significant input
regarding research priorities, objectives, treatments, and design. Experiments will be
located on a grass seed producer’s farm. The producers will perform all cultural practices
with their equipment and provide cattle for the study. They will be responsible for day to
day maintenance of the cattle. Producers from the region will participate in on-site field
tours and as panelists at local and regional meetings.
Outcomes
a. Increasing Producer Knowledge Base:
 New residue management systems will be provided to grass seed growers that will
greatly reduce post-harvest burning of residue and improve air quality, while
minimizing soil erosion.
 Integration of plant and animal factors will create bluegrass residue management
systems that are acceptable to the general public and are economically beneficial
to both grass seed and livestock producers in northern Idaho and eastern
Washington.
 Eliminating the loss of nutrients from burning and residue removal will improve
the on-farm nutrient balance and reduce dependence on inorganic fertilizers.
Understanding the importance of nutrient release in agronomic residues will help
us to develop more economically efficient fertilizer recommendations while
further protecting water quality.
 Maintaining or increasing the acreage of this perennial crop will protect against
erosion, improving soil and water quality.
b. Information Distribution:
 Growers and industry representatives will have access to information through
field tours scheduled at various times during the three year production cycle to
demonstrate residue management effects on livestock and grass seed production.
 Meetings will be conducted throughout the region and will include grass seed and
livestock producers, as well as research and extension personnel.
 A web site will be constructed and maintained to provide grass seed and livestock
producers access to previous and current information associated with grass seed
production.

Results will be published in the appropriate professional journals and
disseminated at professional meetings.
c. Number of Acres/Animals Impacted:
 Approximately 24,300 ha of grass seed are produced in northern Idaho annually.
It is estimated that producers will adopt the use of livestock to remove residue on
20% of the acres, or about 4,800 ha. With a stocking rate of five head per ha, this
would impact about 24,000 head of cattle annually. In addition, another 30% will
adopt mechanical residue removal plus enhanced microbial decomposition.
d. Actual Positive Economic Impact (Dollar Value) to Farm/Ranch Families and
Communities:
 Under current bluegrass production practices where field burning is not allowed,
return per ha are reduced by as much as $398. If successful, these proposed
bluegrass production practices (livestock grazing and/or microbially enhanced
decomposition) would increase direct revenue to grass seed producers in the
region by $4,981,800, if half the production areas adopt the technology. Using a
multiplier of 1.8, direct and indirect benefits to the region would be over $8.9
million.
 Beef cow-calf producers typically operate on an extremely narrow profit margin
and often operate at a net loss. Consequently, cow-calf producers would be
highly motivated to seek methods of reducing operating costs. Feed costs
incurred during the fall and winter is the largest single cost for the cow-calf
producer and often exceeds 50% of the total cost of production of a weaned calf
($180 to $250 per cow-calf unit). It is reasonable to assume that identification of
prudent grazing practices could reduce fall/winter feeding costs by $40 to $60 per
cow, thereby greatly widening the profit margin. We estimate that this benefit
could be achieved from approximately 0.4 ha of grass seed residue and fall
regrowth.
 There will be measurable social and cultural impacts associated with the potential
changes from moving to a non-thermal production system. Farmer, rancher, and
community acceptance will increase with proper assessment of shifts in norms,
customs, and practices related to a regional heritage and identity evolved in
conjunction with burning practices.