Brucellosis Research
The UAF reindeer research program was able to more intensively
sample Seward Peninsula reindeer herds in 1996, with more than
600 samples taken from reindeer which had not been previously
vaccinated. Infection rates of brucellosis ranged from 020%. The
Stebbins herd, which had never been tested, yielded no positive
tests out of 120 reindeer sampled. We were not able to attend
the reindeer handling at St. Lawrence Island due to poor weather
conditions, but will continue with sampling of this herd in 1997
for the purposes of brucellosis free certification. Reindeer herders
have given their support to further research on a vaccine which
will allow serologic discrimination between vaccinated and infected
reindeer. This will help tremendously in monitoring brucellosis
and shipping live reindeer.
Julia Bevins
Barley Breeding and Research
Bulk progenies of several breeding families were advanced
in 1996 as part of the barley breeding program. Progenies consisted
of crosses between Alaska developed varieties including Otal,
Datal, and Thual, with promising lines developed in Scandinavia.
Crosses were made with the objective of developing 1) a covered
barley variety with higher grain yield and maturity at least as
early as Otal, and 2 ) a naked barley variety with earlier maturity
and better straw strength than Thual. Line selection will begin
in several of these crosses in 1998.
Studies comparing maturity date as determined by color observation
and percent grain moisture at harvest showed that either could
be used to identify early maturing varieties. Apparently, the
varieties studied had similar rates of grain moisture loss during
maturation.
Because the production of late developing tillers that fail to
mature influences the productivity of barley in Alaska, the potential
of limited tillering is being studied. Plants have been developed
that contain a mutant gene that produces a single head per plant,
which results in extremely early maturity, but unacceptably low
grain yield. Selection is underway to increase the head size of
these plants. Additionally, lines that contain another mutant
gene that produces two to four tillers per plant are under development
and may offer a compromise between high yield potential and early
maturity.
The inheritance of grain fill rate was studied in a group of
barley lines adapted to Alaska. Grain fill rate was under genetic
control, but because top performing lines had rapid grain fill
rates, it would probably be difficult to improve the grain fill
rate of these lines. Top lines tended to have relatively long
planting-to-heading periods, apparently necessary to produce sufficient
photosynthetic area for high grain yield.
Stephen M. Dofing
Spinach Seed Production Potential
Environmental conditions in Southcentral Alaska were evaluated
for producing spinach seed. Spinach, a daylength sensitive plant,
requires long days to stimulate flowering and relatively cool
temperatures to maximize seed production. Several parent lines
of spinach were grown in the field and spinach seed was produced.
It was determined that Southcentral Alaska has conditions suitable
for producing spinach seed.
Stephen Dofing, James Walworth and Donald Carling
Determining Blood Serum Trace-Mineral Levels in Reindeer
Little is known about the trace element requirements for reindeer.
Current research is establishing baseline data on trace element
blood serum levels of western Alaska reindeer in conjunction with
trace element levels in available forages. Baselines can identify
requirements for minerals such as zinc, phosphorous, iron, magnesium,
copper, calcium, and selenium. These nutritional requirements
are essential for formulating diets of intensively managed reindeer.
Low grade deficiencies or toxic levels of minerals may depress
growth rate and decrease productivity. Proper supplementation
or changes in grazing practices may alleviate problems.
Greg Finstad
Soil and Plant Relationships Affecting Reindeer Productivity
Velvet antlers and meat are commercial products of Alaska's
reindeer industry. Variations in antler and body growth have been
observed between animals of adjoining ranges. Range characteristics
are believed to be responsible for these variations. Reindeer
in Alaska forage year round over large ranges with minimal influence
by herders. Spring and early summer forage provides the essential
protein and minerals needed for body and antler growth. Diet and
habitat selection and its effect of productivity was investigated
in reindeer herds located at White Mountain and Brevig Mission,
Alaska. Microhistological analysis of reindeer feces was used
to identify primary spring, summer, and autumn forage species
primarily sedges, willows and forbs. Forage plants were sampled
throughout the growing season and analyzed for nitrogen, fiber,
trace and macro minerals. Levels of stable isotopes of nitrogen
and carbon were used to determine nitrogen flow and carbon levels
in reindeer forage plants.
Greg Finstad
Radiotelemetry Determines Habitat Usage of Seward Peninsula
Reindeer
Range utilization by Seward Peninsula reindeer was investigated
through the use of radiotelemetry. Radio-collared reindeer are
located throughout the year with the use of fixed wing aircraft.
Seasonal patterns of movement and habitat selection were monitored
to identify and evaluate critical foraging areas. Ground crews
traveled to foraging locations to survey plant community compositions
and monitor usage by reindeer. This data will be used to identify
critical foraging habitats and long term usage patterns. Reindeer
herders and land managers can use this information to implement
optimal grazing plans.
Greg Finstad
Developing a Reindeer Growth Model
Summer and winter body weights of adult male, female, and
castrated reindeer have been collected on the Seward Peninsula
since 1984. A regression model, including categorical variables
of season, sex, and all interaction terms, was developed to assist
the herd manager in making culling decisions. Yearling females
averaged 125 pounds increasing to a 210 pound winter weight and
a 180 pound summer weight at age 10. Yearling males averaged 142
pounds increasing to a 230 pound winter weight and a 285 summer
weight at age seven. Yearling steers averaged 150 pounds increasing
to a 270 pound winter weight and a 265 pound summer weight at
age seven. Age-related rates of gain can be used to determine
optimal slaughter age to maximize meat yield.
Greg Finstad
Usibelli Revegetation Studies
A study was initiated in 1991 to evaluate grass growth on
different growth media on windy, south-facing slopes for cover,
nutrient absorption, and decomposition. An additional study was
implemented in 1995 to assess the effects of fertilization for
varying numbers of years. The sixth and second year of plant cover
and soil nutrient data were obtained for those two studies in
1996.
Norcoast Bering hairgrass (Deschampsia beringensis), a
cultivar developed at the Agricultural and Forestry Experiment
Station, has maintained better cover than most other species on
the once fertilized plots. Cover of many other species has declined
substantially on these plots. Native colonization was greatest
on plots seeded with legumes and consisted mostly of herbaceous
species that follow disturbances, such as fireweed (Epilobium
angustifolium) and bluejoint reedgrass (Calamagrostis canadensis),
although Bebb willow (Salix bebbiana) and paper birch (Betula
papyrifera) also colonized these plots. Aspen (Populus
tremuloides) sprouted from root fragments where an organic
mat was used. Twice-fertilized plots had almost complete cover
while the once fertilized plots had only 60 to 80% cover, which
might be beneficial where native colonization is more important
than erosion control. Arctared and Norcoast provided more than
their share of the cover after two years when testing new seed
mixes.
Dot Helm
Silverado Revegetation Studies
Work continued on revegetation trials begun in 1995 to assess
plant species and fertilizers that would be appropriate for placer
mines in the Upper Koyukuk region. Species tested included Norcoast
Bering hairgrass (Deschampsia beringensis), Nortran tufted
hairgrass (Deschampsia caespitosa), Alyeska polargrass
(Arctagrostis latifolia), Gruening alpine bluegrass (Poa
alpina), Arctared red fescue (Festuca rubra), Tundra
bluegrass (Poa glauca), and Alsike clover (Trifolium
hybridum). All species except the Alsike clover were selected
because of suitability to the environment as well as neighboring
land uses in the Gates of the Arctic National Park and Preserve.
The clover was used because in previous studies it facilitated
natural colonization and then died.
Four seed mixes were also tested in plots as well as in the
actual revegetation of the site. All species and mixes, except
the alpine bluegrass and clover grew well in the fall seedings
(greater than 80% cover). In contrast, the spring seedings had
less than 40% cover, partly because of the shorter growing season.
The fall seedings had already started growing when the spring
seedings were just being planted. Grass cover increased substantially
when phosphorus fertilizer (any amount) was applied, but responded
very little to nitrogen. Natural colonization is also being documented
on reclaimed exploration trails as well as in the main mine area.
Dot Helm
Establishing Woody Plants on Disturbed Lands
The objectives of this study include evaluating longer-term
(5-10 years) effects of growth media or mycorrhizal inoculum on
woody plant growth and natural colonization on three mined sites.
The southernmost site, a proposed coal mine near Palmer, contains
woody cuttings and seedlings planted in 1989 on four growth media:
three soil materials and glacial till (overburden) material. Plant
growth has been substantially better on the three soil-material
sites compared with the glacial till site for the first eight
years. Height growth for many species is beginning to slow on
one growth medium.
Soil was transferred from native vegetation to the root zone
of greenhouse-grown Sitka alder (Alnus sinuata) in 1990
to introduce mycorrhizal inocula from an active coal mine reclamation
project near Healy. Inocula were obtained from a paper birch (Betula
papyrifera) white spruce (Picea glauca) forest with
Sitka alder understory (expected to have appropriate microorganisms)
and from a black spruce (Picea mariana) forest with ericaceous
shrub understory (would not have appropriate microorganisms).
These plants have been monitored for height since 1990.
Seedling colonization is being monitored on an abandoned placer
mine located 100 miles northeast of Fairbanks and reclaimed in
1993. Rooted and unrooted feltleaf willow (Salix alaxensis)
cuttings were planted at three heights above the water and three
times during the growing season to assess their survival and growth.
Rooted cuttings survived much better than unrooted cuttings in
most cases (53% versus less than 5%) with the exception of a low
elevation site protected by a small levee. Best survival occurred
for cuttings transplanted early in the year (60% in June versus
44% in August). This could be partly a factor of the unusual June
rains and somewhat drier July and August. Survival was better
at lower elevations and from earlier plantings. However, plant
heights were greater at higher elevations and least at the lowest
elevations. This resulted from the later icing in the floodplain,
and longer growing season on top of the tailings piles.
It was determined during grass variety trials that the best
grass species were Norcoast Bering hairgrass (Deschampsia beringensis)
and Arctared red fescue (Festuca rubra). June seedings
were best in the first year because of their longer growing season,
but the July seedings have increased their cover and are stable
through the third year. The June seedings started to decline in
cover during the third year, probably due to fertilizer being
depleted.
Dot Helm
Germinating Seeds of Alaska Burnet
Three species of burnet (Sanguisorba spp.) native
to Alaska have potential as ornamentals in wildflower gardens,
perennial flower plantings and roadside revegetation projects.
Seed germination tests were conducted to identify optimum germination
in relation to temperature and light. The greatest percentage
germination in shortest number of days occurred at 77 degrees
F for all three species within a 40 degrees to 86 degrees F test
range. Sanguisorba stipulata did not germinate at 40 degrees
F, and both S. stipulata and S. menziesii showed
less than 50% germination at 86 degrees F. Seeds of all species
germinated as well in darkness as in light.
Patricia S. Holloway and Grant E.M. Matheke
Low Snowfall Causes Winterkill in
Perennial Ornamentals
Total accumulation of snowfall through late January 1996 was
six inches. From October 1995 through January 1996, winter air
temperatures reached 48 · F. The
lack of insulating snow cover combined with low air temperatures
caused a loss of 30% of the perennials at the Georgeson Botanical
Garden. Plant losses ranged from "reliably hardy" species
such as Lonicera tatarica that have been grown in the Interior
for more than 50 years to native plants. Genera that were particularly
vulnerable to winterkill included Aquilegia, Crocus, Dianthus,
Iris, Lilium, Lychnis, Muscari, Polemonium and Tulipa.
More information.
Patricia S. Holloway and Patricia J. Wagner
Effects of Trichoderma atroviride on Phytophthora
cactorum
Isolates of P. cactorum, causal agent of root rot diseases
in ginseng, were obtained from the laboratory of Dr. Parke (University
of Wisconsin). Results of dual culture and other laboratory tests
indicated that T. atroviride is an effective mycoparasite
of P. cactorum. At the macroscopic level, the expansion
of the P. cactorum colony was arrested upon contact with
the mycelia of T. cactorum, and as the mycoparasitism progressed,
the entire P. cactorum colony was destroyed by the T.
atroviride. Microscopically, the hyphae of T. atroviride
were observed to penetrate the hyphae of P. cactorum and
cause lysis of the vegetative hyphae of the pathogen.
Yong Huang and Jenifer. H. McBeath
Inhibiting Effects of Tabtoxin on Expression of Plant Disease
Genes
Transgenic tobacco plants carrying either the Arabidopsis
phenylalanine ammonia lyase (PAL) -glucuronidase (GUS) or bean
chalcone synthase (CHS) -GUS gene fusions were inoculated with
Pseudomonas syringae pv. tabaci strains 11528R (Tox+)
and 11528R (del[tbl]2) (Tox-) to study the effect of tabtoxin
on expression of PAL and CHS genes. The results showed that both
genes were differentially activated in response to inoculation
with 11528R and 11528R (del[tbl]2) by measuring GUS activity in
transgenic tobacco. The temporal induction pattern established
by 11528R (del[tbl]2) showed a higher magnitude and peak expression
of GUS activity than that elicited by 11528R. Results from spatial
pattern analysis indicated that induction of PAL and CHS genes
by both 11528R (del[tbl]2) and 11528R is localized to areas surrounding
bacterial infiltration. However, strong enhancement of PAL and
CHS gene expression was observed at the edge of these areas in
transgenic tobacco leaves infiltrated with 11528R (del[tbl]2)
but not with 11528R. Expression of CHS and PAL genes in transgenic
tobacco leaves treated with heat-killed cells of 11528R (del[tbl]2)
or 11528R showed an elevated but identical induction pattern.
Our results suggest that tabtoxin plays an important role in inhibiting
expression of CHS and PAL genes in tobacco plants.
Yong Huang and Jenifer H. McBeath
Evaluating and Improving Barley Feed
Two studies were conducted to determine the feeding value
and digestibility of whole full-fat canola seed in early weaned
pig diets. In the first study, 50 Landrace X Yorkshire pigs (14.5
pounds) were allotted at 21 days of age to compare growth and
feed performance with canola (Tobin) seed at 4 or 8% and two physical
forms (ground versus whole) in barley diets. There was a tendency
for reduced gains and poorer feed performance at 8% but no difference
was related to physical form. Results would indicate that whole
canola seed should not exceed 4% of the diet and performance would
not be improved by grinding. Six 21 day-old Yorkshire X Landrace
barrows were allotted to start diets {21% crude protein (C.P.),
1.1 % Lysine} that contained 0, 10, and 15% whole canola (Tobin)
seed in a 3x3 Latin Square to determine the digestibility of canola
seed. Dry matter, C.P., ether extract (E.E.) digestibilities were
46, 59, and 39%, respectively. The digestible energy was 1,553
calories per pound.
Fred Husby and Garret Perney
Seed Germination of Pasqueflower
Seeds from 10 populations of pasqueflower (Pulsatilla patens)
with origins from Colorado to Alaska were germinated at temperatures
ranging from 40 degrees F to 77 degrees F. Optimum germination
(greatest percentage) occurred at 77 degrees F regardless of seed
origin. Seeds from Alaska germinated at 40 degrees F, whereas
seeds from other locations did not. Although the optimum germination
occurred at high temperatures for all populations, the Alaska
seeds showed a broader range of germination temperatures, indicating
an adaptation to cold soils.
Sarah Johns and Patricia S. Holloway
Fertilizing Lettuce, Tomato and Petunia Transplants
Five different commercial fertilizers (Peters Peat-Lite Special
® 151617, Fison TechniGro ®
161717 Plus, 20920 Plus, 17524 Plus, and 15015 Plus) were
used to study the importance of phosphorous for lettuce, tomato
and petunia transplants. The growing substrate was Sunshine ® Mix. The amount and rate of growth were
similar for transplants grown with 151617, 161717, or 20920. Slow
growth, low flower number and plant weights were observed for
plants grown with 17524 or 15015. Using 17524 or 15015 to produce
transplants cannot be recommended. The lower level of phosphorus
in 20920 did not, however, cause adverse plant growth.
Meriam Karlsson
Control of Flowering in Windflower
Flowering in windflower (Anemone coronaria L.)
was studied at 54 degrees, 60 degrees, and 68 degrees F and 8,
12, and 16 hours day length. Flowering was first observed 19 weeks
from seeding at 16 hours day length and 60 degrees F. Five additional
days were required at 54 degrees F and 15 more days at 68 degrees
F compared to 60 degrees F for flowering. The number of leaves
at flowering increased from nine at 54 degrees F to 12 at 60 degrees
F and 15 at 68 degrees F.
Meriam Karlsson
Control of Flowering in Cyclamen
Cyclamen (Florist's cyclamen, Alpine violet) was grown at
68 degrees F and 16 hours day length for 16 weeks. Plants were
then placed at conditions with 60 or 68 degrees F and 8, 12, or
16 hours day length. The development and appearance of the first
open flower was faster at 60 degrees F than 68 degrees F. The
length of the day did not alter the rate of flowering. On average,
79 days from starting the different temperatures and day lengths
were required for flowering at 60 degrees F and 87 days at 68
degrees F.
Meriam Karlsson
Canola Production
Eight varieties of Polish canola (Brassica rapa), `AC
Sunshine', `Colt', `Eldorado', `Goldrush', `Horizon', `Maverick',
`Reward', and `Tobin', and one variety of Argentine canola (Brassica
napus) `Sprite' were planted at three locations in Interior
Alaska. Crop emergence was late and early growth was slow due
to weather that was cooler and drier than normal during May and
June. All varieties of Polish canola ripened at Delta Junction
and North Pole. The Fairbanks location was extremely dry and none
of the varieties ripened. Argentine canola is later maturing than
Polish canola and the variety `Sprite' did not fully mature at
any location. Seed yields were not significantly different among
the Polish varieties and averaged 0.39 tons per acre at Delta
Junction and 1.4 tons per acre at North Pole.
A private party is in the process of erecting a used canola
crusher in Alaska and several farmers associated with the Deltana
Community Corporation planted field scale tests of canola in 1996.
Yields were low and results were mixed, but interest is still
high and further tests using irrigation are planned for 1997.
Charles Knight
Small Grain Variety Trials
Early maturing varieties of spring planted small grains from
Alaska, Canada, Norway and Finland were evaluated at three locations
in Interior Alaska. Seed yield and date of maturity were the primary
evaluation criteria. Among feed barley varieties, `Otal' had the
highest consistent yield at all locations, producing an average
of 1.63 tons per acre. Among spring oat varieties, yields of `Toral',
`Cascade' and `Calibre' were approximately equal with an average
of 2.1 tons per acre.
In response to microbrewery demands for an Alaska produced malting
barley, evaluations of early maturing malting barley varieties
were expanded in 1996. The varieties, `B 1215', `B 1602', `C&V
Expt.', `Duel', `Harrington', `Stander' and `Stetson' were evaluated.
Highest yields were obtained with `Duel', however, test weights
were low due to the short growing season. At the Fairbanks location,
`B 1215', C&V Expt.' and `Harrington' produced test weights
of 48 pounds per bushel or greater and had an average yield of
2.28 tons per acre. Evaluations of malting barley varieties will
continue in the future with the goal of finding an early maturing
variety which will consistently produce high quality seed.
Charles Knight
Vitamin B 1 and Transplant
Roots
Solutions of vitamin B 1 are sold in
garden centers as soil drenches to promote rapid growth of newly
transplanted seedlings. Vitamin B 1 supposedly
promotes root growth which, in turn, aids in rapid seedling establishment.
This hypothesis was tested using `Hero Yellow' marigolds grown
in cell packs in the greenhouse. Root growth was not greater in
vitamin B 1 treatments applied with and
without a liquid fertilizer as opposed to plants receiving a water
drench. No differences in growth of roots, shoots, and leaves
were detectable with the vitamin B 1 or
fertilizer treatments. The value of vitamin B 1
drenches is questionable.
Collin Lichtenberger and Patricia S. Holloway
Controlling Fungus on Potatoes
Trichoderma atroviride is a fungus found in Alaska
that is capable of parasitizing a wide range of plant pathogenic
fungi. In a three year field study conducted previously in Alaska,
T. atroviride was found to be equal to or better than chemical
fungicides in controlling black scurf disease of potatoes caused
by Rhizoctonia solani. The purpose of this study is to
evaluate the efficacy of four isolates of T. atroviride under
conditions different from Alaska. This is the third year of this
study. My collaborators in this project were Dr. M. Sun and Ms.
E. Carpenter, Potato Laboratory, Montana State University, Bozeman,
Mont.
Trials were conducted under large acreage commercial field settings in Ronan and Columbia Falls, Mont., testing the efficacies of T. atroviride for controlling R. solani of potatoes. To simplify the application for producers, an equal proportion of Trichoderma atroviride isolate CHS 861, CHS 901, Biotype 453, and Biotype 603, were blended to form one variable. The other variable included Topsin M chemical control and two binucleate Rhizoctonia isolates. All of the variables were applied as seed treatments. Materials were given to the collaborating potato growers to incorporate in their potato planting.
The record cold and wet weather in the spring seriously affected
the planting and performance of the potatoes in the trials. Because
of the large scale of the trials, considerable variations were
found in soil types, soil moisture level, etc. among treatments.
Furthermore, the blank control was inadvertently left out of the
trial by potato growers. Consequently, results were inconclusive.
Jenifer H. McBeath
Evaluating Lettuce Varieties
Tip burn, a physiological disease caused by a calcium deficiency,
is one of the most important diseases on lettuce in Alaska. The
rapid growth of lettuce due to the long day length during the
growing season makes lettuce particularly prone to this disease.
Basal rot, caused by Sclerotinia sclerotiorum, and gray
mold, caused by Botrytis cinerea, can also be severe under
certain environmental conditions. Damage to lettuce production
caused by these diseases has resulted in great economic losses
to lettuce farmers each year. Treatments such as applying calcium
to the soil or as a top dressing were all found to be ineffective.
A lettuce variety trial was initiated in 1991, in collaboration
with Ms. P. Giauque (lettuce farmer) and Mr. P. Sorreal (lettuce
breeder, Harris Moran Co.). In 1996, 32 lettuce varieties and
breeding lines were evaluated. Disease occurrences of tip burn
on lettuce was moderately severe; several head lettuce varieties
showed marked resistance to this disease. Infestation of Botrytis
cinerea and S. sclerotiorum were fairly mild on lettuce.
Several varieties and breeding lines were found to possess fairly
good resistance to these diseases.
Jenifer H. McBeath
Effects of Trichoderma atroviride on Phytophthora
infestans
Effects of Trichoderma atroviride on the growth and
development of Phytophthora infestans (A1 and A2 strains)
were studied. Two isolates of A1 and A2 strain and an isolate
of A2 strain of P. infestans were obtained from Dr. Fry
(Cornell University). An A2 isolate of P. infestans was
provided by Dr. Nelson (University of Arizona).
Results of dual culture and other laboratory tests indicated
that Trichoderma atroviride is an effective mycoparasite
of P. infestans. At the macroscopic level, the expansion
of the P. infestans colony was arrested upon contact with
the mycelia of T. atroviride, and as the mycoparasitism
progressed, the entire P. infestans colony was destroyed
by the T. atroviride. Microscopically, the hyphae of T.
atroviride were observed to penetrate the hyphae of P.
infestans and cause lysis of the vegetative hyphae of the
pathogen. Although T. atroviride hyphae penetrated into
the sporangia of the P. infestans and displaced the cell
contents, the cell walls of sporangiophore and sporangia appeared
to be intact.
Jenifer H. McBeath
Alaska Seed Potatoes for Export
Geographic isolation and harsh winters provide Alaska distinct
advantages in producing premium quality seed potatoes which are
free from major viruses, bacterial ring rot, late blight (A1 and
A2 strains) and golden nematodes. The objective of this project
is to develop premium quality seed potatoes for export to other
states and countries. It will benefit potato growers directly
as well as help diversify the state's economy (and reduce federal
deficits caused by trade imbalances). In the summer of 1996, 700,000
data points were collected from seed lots at nine farms. We found
no presence of late blight and bacterial ring rot disease in any
of the fields we tested. We also found six potato farms completely
free of virus disease, which supports the thesis that it is possible
to produce virus-free potatoes in Alaska. We found no evidence
of virus transmission by insect vectors. It seems that contaminated
seed potatoes are the primary source of virus diseases in Alaska.
In February 1996, a special permit was granted from the People's
Republic of China for a trial shipload of premium Alaska seed
potatoes to China. In September 1996 a three member Chinese Delegation
conducted a 10 day, pre-sale inspection in Alaska. In November
1996, 660 pounds of premium quality Alaska seed potatoes were
shipped to Taiwan for trial.
Jenifer H. McBeath and Yong Huang
Vegetating Gravel Structures
The experiment began in 1989 with restructuring an exploration
gravel pad to test effects of gravel thickness, a small topsoil
application, capturing snow, and seeding with native plant species
collected in the Prudhoe Bay vicinity. Three-inch deep topsoil
was the most beneficial treatment, increasing vascular plant canopy
cover from 32% without topsoil to 56% with topsoil after six growing
seasons. Moss cover increased from 3% without topsoil to 39% with
topsoil. Increasing gravel thickness reduced moss and grass cover
and had less influence on forb cover. Benefits from snow fencing
were confined to the first three to five growing seasons. Average
canopy cover increased from 0 to 66% in six years. Puccinellia
langeana (a native alkaligrass) was the most competitive grass
in early stand development. After six growing seasons, this species
appeared to be declining in vigor, indicating it was being replaced
by other species. Grasses began sexual reproduction (seed development)
after two growing seasons. Perennial forbs required four to six
growing seasons to begin seed production. Seed applications were
0, 40, 80, and 880 seeds per square foot. The higher applications
resulted in dense grass stands early in the experiment, and these
dense grass stands competed heavily with forb species, reducing
plant diversity.
Geese, ground squirrels, and small birds have been observed feeding
on foliage and seeds in the test plots, indicating a functional
plant community was forming. The moss development indicates soil
building processes are also beginning. The experiment demonstrates
the potential for revegetation of gravel fill in Alaska's arctic
oil fields. Other studies are underway to test effectiveness of
using various waste products from the oil field operations to
enhance gravel as a medium to support tundra plant growth.
Jay D. McKendrick
Long-term Tundra Revegetation
The project objective is to permanently mark and document
test plots and photopoints of experiments previously conducted
across Alaska's North Slope to provide Long-term documentation
of vegetation changes in tundra. Revegetation experiments which
began in 1972 were usually concluded after three years, but the
most useful information from these tests materialized after 10
or more years. Interpretations from some of these Long-term observations
caused us to reverse earlier conclusions and significantly changed
our recommendations for rehabilitating damaged tundra. Plant species
and seed and fertilizer applications recommended in the mid-1970s
have proven inappropriate for certain habitats over the Long-term
if natural tundra restoration is the primary objective. It is
believed that more valuable information, which will assist those
involved with tundra revegetation, can be obtained from these
experiments in the future. Photo records illustrate the reinvasion
of tundra plants on damaged sites where no revegetation efforts
were used, indicating the profound but poorly recognized natural
resilience for the biota in this environment. Documenting these
responses should prove valuable for future resource developments
in the region by indicating options to accelerate tundra rehabilitation
processes and that disturbances have a greater natural potential
for recovery than generally acknowledged.
Jay D. McKendrick
Grass Clipping Mulches Control Weeds
`Provider' bush beans and `Celebrity Red Morn' petunias were
grown in plots mulched with fresh grass clippings or in unmulched
plots. Mulch was applied beginning June 10 and continued weekly
to maintain a three-inch mulch layer. Weed control on mulched
plots was excellent. Total seasonal maintenance labor was reduced
by 17 minutes on the 48 square foot petunia plots. Maintenance
on the 200 square foot bean plots was reduced by 30 minutes with
the grass mulch. Yield of snap beans and flowering on petunias
did not differ between mulched and unmulched plots.
Grant Matheke, Thekla Johnson, Kathy Seim, and Cathy Egan
Rate of Moisture Loss from Cut Forage
Drying conditions during first cutting (mid to late June)
were highly favorable. Cut grass dried to 20% moisture in 2.5
to 5.5 days, due to low humidity, high temperatures and a lack
of clouds. Second cutting grass did not reach 20% moisture over
an eight day drying period. Rainfall was lower than normal during
the second cutting, but high humidity, lowering temperatures,
and cloudy weather prevailed. These studies will continue for
several years, so the economic consequences of management decisions
can be evaluated.
Michael T. Panciera
Establishing Minimum Tillage Forage
Preliminary studies suggested that minimum tillage would be
effective for small-seeded forage crops. A minimum tillage drill
was constructed and initial testing was completed during 1996.
The drill will be used to test the responses to minimum tillage
planting for bromegrass, timothy, clovers, and brassica crops
in 1997.
Michael T. Panciera
Kentucky Bluegrass Seed Production
`Nugget' Kentucky bluegrass is one of the best varieties of
turfgrass for Alaska. The characteristics that make it a good
sod crop create problems for seed production. Seed yields decline
rapidly as the stand thickens. An on-farm trial was established
in Delta Junction to determine whether nitrogen rates and clipping
management will affect the productive life of stands used for
seed production.
Michael T. Panciera and Stephen D. Sparrow
Cutting Date Effects on Alfalfa
Alfalfa planted in 1994 was subjected to different cutting
treatments for two years. The timing of second cutting was very
important in both yield and survival. Stands that were cut between
mid-August and mid-September had the lowest yields, plant numbers,
and root reserves. This study is being conducted at Point MacKenzie,
Fairbanks, and Delta Junction. Over the past two years winter
conditions have been severe enough to cause extensive winterkill.
More studies are needed to determine the best cutting management
for alfalfa in Alaska.
Michael T. Panciera and Stephen D. Sparrow
Permafrost Soils Characteristics
The Arctic is the region of greatest expected change due to
its large soil carbon stores and extensive wetlands. Therefore,
it could act as a large positive feedback to global warming. The
specific objectives of this study are to characterize the morphological,
chemical, and physical properties of the cryogenic soils, and
to estimate the carbon storage in soils of different ecosystems.
Soils were studied along a north-south transect in the Kuparuk
River Basin of Arctic Alaska. [Soil pits were selected to represent
major land cover classes. Each pit was excavated to 3 feet wide
and at least 3 feet deep unless the permafrost layer was deeper
than 3 feet or excavation was limited by bedrock. Soil profiles
were described and sampled according to the Soil Survey Manual.
Special attention was paid to the cryogenic structures, ice content,
and depth of permafrost tables. Soil samples were analyzed according
to the USDA National Soil Survey Laboratory procedures.]
Soils on the coastal plain with wet, nonacidic tundra vegetation are poorly to very poorly drained. Soil occurring on low-centered polygons or waterways have 6 to 10 inches of organic material and on flat or high-centered polygons have less than 15 inches organic layers over fluvial deposits. These soils have an alkaline reaction due to carbonates deposit on the soil surface. Ice wedges are common and their volume increases from younger (low-centered polygon) to older (flat polygon) sites. Ice lenses are also common but are weakly developed and coarser than in the tundra soils. Soil textures are peat and muck in the organic layers and sandy or coarse loamy in the mineral substratum.
There are two major soil groups on the glaciated foothills south of the coastal plain. Moist, nonacidic tundra soils formed in calcareous loess over glacial till along the northern fringe of the foothills. Moist, acidic tundra soils formed in loess over glacial till, extending from south of the nonacidic tundra zone to the footslopes of the Brooks Range. Both of these types of soils have strongly developed cryogenic profiles. Ice wedges and strongly developed fine ice lenses in subsoils are common. The surface organic layer consist of partially to well decomposed organic matter. The subsoils are loamy or silty and are generally gleyed or strongly mottled suggesting a fluctuating water table and reduction with the rise and fall of permafrost. The upper permafrost layers have mucky silty loam texture and well developed ataxic structures (icerich). The continuous buried organic horizon under the cryoturbated organic material in the lower active layer suggests a paleoorigin which has been modified by the cryogenisis.
Soils along the water tracts and drainages are very poorly drained, and inundated during most of the growing season. The submerged organic layer is dominantly muck overlying a strongly gleyed mineral subsoil. Soils formed in depressions and valley bottoms are dominantly organic with peat and muck layers exceeding 20 inches. Due to their landscape positions, these soils are stratified with thin layers of mineral soils.
Soils on the sparsely vegetated upland and alpine tundra do
not have permafrost within 3 feet of the surface. The seasonal
freeze-thaw cycle has resulted in strongly developed granular
and platy structures in the B horizons. The organic matter accumulation
rate is very low. These soils generally have a redder hue due
to well-drained conditions. Soils along the major river channels
also lack permafrost within 3 feet of the surface. These soils
are coarse textured and excessively drained. Under shrubby vegetation
cover, humus accumulation has produced an A horizon, generally
less than 8 inches thick.
C.L. Ping
Soil Environment Monitoring
The objectives of this study are to monitor the soil temperature,
water table, and soil reduction-oxidation potentials, and to relate
these measurements to the hydric soils criteria used for wetland
delineation. Four sites were selected along a landscape sequence
including bottom land, footslopes and toeslopes in a watershed
on Douglas Island in Southeast Alaska. The monitoring sites were
selected because an oxyhydric condition was suspected in the area.
Based on first year's results, the soils experienced both saturated
and reduced conditions during the growing season, thus they meet
the hydric soils criteria. There are two separate water tables
identified; an unconfined one in the upper 3 feet conditioned
by surface infiltration and a confined one in the underling glacial
till. There seems to be little exchange between the two aquifers.
C.L. Ping and D. D'Amore
Characteristics of Soil Organic Matter in Permafrost Soils
The objectives of this project are to estimate the quantity
and quality of soil organic matter in Arctic tundra soils and
to relate those parameters to trace gas flux in the Arctic tundra
ecosystems. Permafrost soils account for 13% of the total land
surface but they store nearly 30% of the total terrestrial carbon.
Carbon storage in the coastal marsh and depressions, in the upland
moist tundra, and in the foothills range from 200 to 270, 115
to 230, and 30 to 115 pounds carbon per cubic yard, respectively.
These data indicated that the previously reported amount of carbon
storage in the Arctic tundra was underestimated by a factor of
two. The upland tundra soils have buried organic horizons indicating
the presence of paleosol with carbon14 isotope ( 14
C) dating of 7 to 8000 years before present. The delta
13 C values range from 27 to 32 0
/ 00 indicating the dominance of
C3 plants in early Holocene. The bioactivity of soil organic matter
was first assessed by chemical extraction with dilute alkali solution.
In organic soils, less than 30% of the total carbon are extractable
(soluble) because it is less decomposed as compared with the mineral
horizon in which more than 50% are extractable. The carbon content
of soil organic matter ranges from 24 to 52% which is lower than
the 58% in soils of the temperate region. The dominant components
in the extractable fraction is humic acids, followed by neutrals,
fulvic acids, and low molecular weight acids. Most of the non-extractable
fraction are hemicelluloses and cellulose.
C.L. Ping and G.J. Michaelson
Annual Forage Crops
The objectives of this study were to determine the forage
yield and quality of forage peas and vetches grown in monoculture
and intercropped with oats at various nitrogen (N) fertilizer
levels, to estimate the N fixation potential of peas and vetches,
and to provide an economic comparison among these crops with forage
crops currently grown in Alaska. Treatments consisted of monoculture
oats fertilized at five N rates and `Lana' purple vetch, common
vetch, `Carneval' peas, and `Trapper' peas in monoculture and
intercropped with oats at two N rates. The study was done at four
locations: Delta Junction, Fairbanks, and Nenana in Interior Alaska
and Point MacKenzie in Southcentral Alaska. Vetches gave very
low yields at all locations. Yields at Point MacKenzie were low
(usually less than one ton per acre) with little difference among
treatments. This was likely due to water stress at that location.
Yields at all Interior locations were much higher than at Point
MacKenzie, often exceeding two tons per acre and occasionally
reaching four tons per acre. At Delta Junction, oat yields for
all but the zero N treatment exceeded pea or intercropped oat-pea
yields. This was, in part, due to moose grazing on the pea pods.
At Fairbanks and Nenana, total dry matter yields for oat-peas
without N fertilizer were usually slightly lower than for fertilized,
mono-cropped oats, but protein yields were higher for the oat-pea
mixtures. Forage quality analyses other than protein are underway.
Stephen D. Sparrow and Jeffrey B. Midguard
Soil and Crop Management Practices
The purpose of this experiment was to study the Long-term
effects of various soil and crop management practices on dry matter
yield, plant protein, nitrogen fixation, and soil biological,
chemical, and physical properties. Plots were established at Point
MacKenzie in Southcentral Alaska in 1991 and at Delta Junction
and Fairbanks in Interior Alaska in 1992 and were monitored for
five growing seasons. Crops included perennial forage legumes,
perennial grasses, annual grains, and a non-cropped fallow treatment.
Each plot was split with one part receiving an annual application
of nitrogen (N) fertilizer and the other part receiving no N fertilizer.
Above and below ground plant dry matter yields and plant N concentrations
were measured each year for each species. Soil properties measured
included organic carbon (C), total N, pH, microbial biomass C,
and wet aggregate stability. Survival of legumes was poor at Delta
Junction, with all but alfalfa dying off during the first winter.
Alfalfa persisted throughout the study, but stands and hence yields
were poor. At Point MacKenzie, Long-term survival of red clover
was quite good. At Fairbanks, survival of red clover and alfalfa
was good, and high yields were obtained throughout the study.
Nitrogen fertilization resulted in dramatic yield increases for
non-legume crops. Some legumes showed no response or negative
response to N fertilizer, indicating that they were able to fix
adequate amounts of atmospheric N. Total soil C and N did not
change substantially during the course of the experiment. By the
end of the study, wet aggregate stability was highest in the perennial
crops and lowest in fallow. Soil microbial biomass C was highly
variable with no consistent trends evident except that values
tended to be highest in soils cropped to perennial legumes.
Stephen D. Sparrow and Michael T. Panciera
Managing Bluejoint
Bluejoint grass (Calamagrostis canadensis), a native
Alaska grass, can be a serious weed on pasture land in Alaska
because it often out-competes introduced forage grasses. Bluejoint
produces fairly good quality forage early in the growing season,
but the quality decreases rapidly as the season progresses. Often,
using herbicides is not an option for controlling bluejoint. The
purpose of this study was to determine if various mowing treatments,
combined with various nitrogen (N) fertilizer treatments, would
improve the late season forage quality of bluejoint or control
its growth thus allowing more desirable species to grow. Fertilizer
treatments included no N fertilizer, N fertilizer applied once
at the beginning of the growing season, or split applications
where N fertilizer was applied once early in the season and again
when first mowed. Mowing treatments included none, single or triple
cuttings done at different times during the growing season. The
study was done near Delta Junction. In both 1995 and 1996, addition
of N fertilizer resulted in substantial yield increases but only
small increases in late season forage quality indices. Mowing
in June resulted in a fair amount of regrowth; mowing in mid-July
or later resulted in little regrowth of bluejoint.
Stephen D. Sparrow and Michael T. Panciera
Microbial Degradation of Hydrocarbons
Principles developed in laboratory studies have been applied
to a petroleum-contaminated North Slope gravel pad. The pad, which
is composed of coarse sand, holds very little water, and was expected
to be sensitive to over-fertilization. Fertilizer treatments applied
in the field revealed that whereas bioremediation could be stimulated
with a small (1.4 ounces per pound) application of nitrogen, slightly
larger applications (2.8 or 4.2 ounces per pound) inhibited bioremediation.
Soil receiving 4.2 ounces nitrogen per pound showed less microbial
activity than soil that was not fertilized.
James Walworth and Joan Braddock
Tuber-Setting Properties of Potatoes
Potato tuber formation and development is affected by genetics
and environment. One environmental factor affecting tuber formation
is nitrogen supply. We are evaluating the impact of nitrogen supply
on several varieties of potatoes by removing plants weekly throughout
the growing season and measuring and counting all tubers at each
monitoring interval. We have found that increasing nitrogen supply
to the plants increases vine size and tuber production, but does
not delay tuber initiation or development. In some varieties,
however, high levels of nitrogen fertilizer can increase production
of oversized tubers which are of lesser value than medium-sized
tubers.
James Walworth and Donald Carling
Head Lettuce Variety Trial
Fifteen head lettuce varieties were evaluated in replicated
trials and in two on-farm observation trials in 1996. Three field
planting dates were used, corresponding to early, intermediate,
and late planting dates of commercial growers. Traits measured
included head size and weight, tip-burn resistance, percentage
of heads with defects, and days to harvest. When combined with
data obtained in 1995, Tiber had the highest level of tip-burn
resistance, 20% above the mean of all varieties tested. Its head
size, however, was larger than desired, and will limit its production
in Alaska. Other varieties having desirable size, tip-burn resistance,
and low percentage of head defects were Premier and Pybas 142E.
James Walworth, Don Carling, and Steve Dofing
Bioremediation of Petroleum Contaminated Cold Region Soils
Through this research, optimum soil nitrogen levels for restoring
petroleum-contaminated soil have been related to both soluble
soil nitrogen and soil water content. In dry soils, where inorganic
nitrogen is dissolved in a relatively small quantity of soil water,
microbial populations can be adversely affected by modest levels
of nitrogen fertilizer, and bioremediation can be inhibited. We
have developed a simple method for calculating maximal fertilizer
application levels.
James Walworth, Mike Reynolds (USA-CRREL), and Craig Woolard
(UAA)
A Nutrient Source for Bioremediation
Nitrous oxide, a nitrogen-containing gas, is being tested
as a fertilizer for bioremediation systems. Effectiveness of this
form of nitrogen has not previously been established. We have
demonstrated that biological degradation of soil petroleum is
stimulated and nitrous oxide consumed when nitrous oxide is added
to contaminated soils. If further testing confirms these findings,
nitrous oxide could become an alternative to the use of solid
or liquid nitrogen fertilizers in bioremediation systems.
James Walworth and Craig Woolard
Evaluating Weed Control Options
Vapam (metam sodium) and basamid (dazomet) are being evaluated
for weed control in potato and vegetable production rotations.
Both materials are soil sterilants and kill weed seeds as well
as growing plants. These materials are being used as onetime treatments
to reduce weed populations to manageable levels. After their use,
annual weeds in vegetable fields can be controlled through traditional
manual techniques. Our studies indicate that use of vapam or basamid
can reduce overall weed control costs, improve weed control, and
reduce the annual use of herbicides. Vapam is currently labeled
for this use, whereas basamid is not yet labeled for use in food
crop production.
James Walworth and Donald Carling
The Use of Alaskan Fish Meal as a Nutrient Source for Bioremediation
Fish bonemeal, a processing by-product, has been tested as
a fertilizer for bioremediation of petroleum-contaminated soils.
Fish bonemeal is rich in nitrogen and phosphorus which it releases
as it decomposes. This provides nutrition for soil microbes that
degrade petroleum over a long time. This research was conducted
to measure rates of nutrient release under various soil conditions
and to evaluate behavior of bonemeal in petroleum-contaminated
soil. Laboratory tests indicate that fish bonemeal can be an effective
fertilizer for restoring contaminated soils.
Craig Woolard (UAA) and James Walworth
[ Agricultural and Forestry Experiment Station | Department of Plant, Animal and Soil Sciences ]