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Rejection criteria for open-path Fourier transform infrared spectrometry during continuous atmospheric monitoring
Get PDFOver 32,000 interferograms measured during open-path Fourier transform infrared (OP/FT-IR) measurements at dairy and hog farms were
evaluated for anomalies. Five types of anomalies could be distinguished: a reduction in the interferogram intensity because of weather-related
optical misalignment; an increase in the amplitude of interferograms measured with too short a path-length that leads to a non-linear detector
response; a periodic interference caused by wind-induced vibrations; the presence of spikes in the interferogram; and an increase in the noise level
of the interferogram (and hence of the spectrum) because of the effect of electrical interference. Prior to testing for the presence of anomalous data,
each interferogram is subjected to a high-pass filter. A noise level index is then calculated from the wings of the interferogram and interferograms
are rejected if the value of this parameter is too high. When the criteria developed in this project are applied, OP/FT-1R spectra may be measured at
1-min intervals over a period of several days
Sediment and polyacrylamide effects on seepage from channeled flows
Get PDFSeepage from water streams into unlined channels determines the
proportion of water distributed to adjacent soil for plant use or soil or
groundwater recharge or conveyed to downstream reaches. We conducted
a laboratory study to determine how sediment type (none, clay,
and silt), sediment concentration (0, 0.5, and 2 g Lj1
), and water-soluble
anionic polyacrylamide (PAM) concentration (0, 0.4, and 2 mg Lj1
)
inf luences seepage loss of irrigation water (electrical conductivity =
0.04 S mj1
; sodium adsorption ratio = 2.2) from unlined channels in silt
loam soil. In a minif lume, a preformed channel with 7% slope was
supplied with 40 mL minj1 simulated irrigation water inf lows containing
the different treatment combinations. Runoff and seepage rates and
runoff sediment were monitored for 24 h. Average 23-h cumulative
seepage loss was 11.8 L for silt-loaded inf lows, 2.8 L for clay-loaded
inf lows, and 6.4 L for f lows without sediment. Increasing inf low clay
concentrations, 0, 0.5, and 2 g Lj1 clay, decreased cumulative seepage
volume (23 h) for the no-PAM treatment from 12.4 L to 6.7 and 0.2 L,
respectively. Increasing inf low silt concentrations in no-PAM treatments
resulted in a curvilinear response with a seepage volume maximum
occurring for the 0.5-g Lj1 treatment (12.4, 47.1, and 9.8 L, respectively).
Increasing inf low PAM concentrations increased seepage volumes
for 2-g Lj1 silt and 2-g Lj1 clay treatments but decreased seepage
for the 0.5-g Lj1 silt treatment. Seepage losses from these unlined
channels can be significantly altered relative to untreated controls by
manipulating the sediment particle size and concentration and PAM
concentration of irrigation water inf lows. Their effects on induced
seepage changes are complex, strongly controlled by factor interactions,
and appear to involve a number of mechanisms
Irrigation-induced erosion
Get PDFIrrigation-induced erosion is one of the most serious sustainability issues in
agriculture, impacting not only the future strategic and commercial viability of irrigation
agriculture, but also the survival and comfort of earth's human population.
Preventing irrigation-induced erosion to maintain the high crop yield and quality
advantages of irrigated agriculture is also a key to the preservation of natural
ecosystems. This is because replacement of irrigated production requires two to
three times the equivalent rainfed production area to match any lost irrigated production
(Sojka, 1998)
Assessing microbial community diversity using amplicon length heterogeneity polymerase chain reaction
Get PDFIt is thought that a microbial community is an assemblage of organisms, genes, and gene
functions. Transient, acute signals such as excessive nutrient loads or disturbance and chronic
signals such as seasonal temperature or rainfall impact the total environmental system. The
goal of many microbial ecologists is to determine if a finely resolved study of microbial
dynamics can be used as a large-scale biosensor to follow diversity patterns in the environment.
With the development of new genomic tools, community-level studies have been
designed that can interrogate the finer details of the biological components of a given habitat.
Amplicon length heterogeneity polymerase chain reaction (LH-PCR) interrogates the
hypervariable domains of the ribosomal small-subunit genes and separates these domains
based on the naturally occurring sequence lengths of DNA. The amplicons are phylogenetically
relevant in that the various amplicons generated can be directly associated with specific
taxonomic sequences archived in the databases. The application of the LH-PCR technique as
a monitoring tool for microbial ecology has been shown to enhance and extend the current
understanding of the dynamics of microbial communities in their specific environments
Seventy-five years of breeding dry bean of the western USA
Get PDFA periodic comparison of cultivars is essential
to assess selection gains, determine deficiencies,
define objectives, and set breeding priorities.
Our objective was to assess the progress,
or lack thereof, achieved in improving yield,
plant type, maturity, and resistance to major
bacterial, fungal, and viral diseases of dry bean
of the western USA from 1918 to 1998. Twenty-five
great northern, pink, pinto, and red cultivars
were evaluated for seed yield at three locations
in Idaho and for anthracnose, Bean common
mosaic virus, Bean common mosaic necrosis
virus, common and halo bacterial blights, Fusarium
and Rhizoctonia root rots, Fusarium wilt, and
white mold in Colorado, Idaho, and Washington
between 1999 and 2006. Yield ranged between
2904 kg ha-1 for pinto 'UI 111' to 3921 kg ha- 1
for 'Bill Z', which represents a 35% gain in 54
yr. Yield gain in great northern was 587 kg ha-1 ,
pink 136 kg ha-1 , and red 687 kg ha- 1 . Stability
indices ranged from 0.57 for 'Kodiak' to 1.86 for
'UI 3'. Maturity ranged from 90 d for 'UI 320' to
97 d for 'Frontier'. Seed weight ranged from 28
g for 'Viva' to 41 g for UI 320. An acceptable
degree of resistance to Rhizoctonia root rot was
achieved in most cultivars. All cultivars were
susceptible to anthracnose, common bacterial
blight, and white mold, and all except 'Chase'
to halo blight. Only 'Matterhorn', 'Weihing', and
Kodiak combined an upright Type II growth
habit with resistance to BCMV and rust. An integrated
breeding strategy should be explored for
simultaneous improvement of multiple traits in
future cultivars
Catch-can performance under a line-source sprinkler
Get PDFA line-source sprinkler configuration provides a linearly decreasing irrigation application rate perpendicular to
the sprinkler line and has been utilized to study crop response to variable irrigation amounts. The effect on measured irrigation
application depths from using various types of catch-cans in those studies is not known. Derived relationships between crop
yield and applied water is dependent on the accuracy of measured catch-can water volumes. The purpose of this study was
to evaluate catch-can characteristic effects on measurement of sprinkler irrigation depths in a line source. This was
accomplished by evaluating six types of catch-cans: (1) 83 mm diameter polypropylene separatory funnel
(with evaporation-suppressing oil), (2) 82 mm diameter PVC reducer can (with evaporation-suppressing oil), (3) 151 mm
diameter metal can, (4)64 x 59 mm wedge rain gauge, (5) 146 mm white plastic bucket, and (6) 100 mm diameter clear plastic
funnel rain gauge. The cans were placed at five application rate conditions (2.8, 5.5, 8.7, 12.6, and 14.8 mm/h). Cumulative
catch depths differed among the catch-can types. However, only the metal can and white bucket cumulative application depths
at the lowest application rate were statistically different from those of the control (separatory funnel). Catch-cans with a
larger diameter opening exhibited less variation in catch depths. Measured evaporation of standing water from catch-cans
varied from 0.04 mm/h (funnel rain gauge) to 1.81 mm/h (separatory funnel without evaporation-suppressing oil). Water
applied to a bucket's sidewall evaporated at a higher rate than standing water. Inaccuracy of application depth measurement
may occur at low application rates even when catch-cans meet the ASAE Standard. The relatively good performance of the
funnel rain gauge and catch-cans with evaporation-suppressing oil (and subsequently less depth than the ASAE Standard
requires) suggests that it may be appropriate to re-evaluate the standard to consider such devices
Evaluating the surface irrigation soil loss (SISL) model
Get PDFAlthough the percentage of surface irrigated land in
the United States is declining, it is still used on
43% of the irrigated land, and 51% of the surface
irrigated land is irrigated down furrows or rows
(USDA, 2004). Water flowing in irrigation furrows often detaches
and transports soil, reducing crop productivity and impairing
off-site water quality. Crop yields were at least 25%
less on fields eroded from over 80 years of furrow irrigation
in south-central Idaho (Carter et al., 1985). Measured soil
loss from furrow irrigated fields in this area varied from 1 to
141 Mg ha-1 annually (Berg and Carter, 1980) while the annual
average soil loss from the entire irrigated tract was 0.46 Mg
ha-1 in 1971 (Brown et al, 1974). This soil, and associated nutrients,
is transported with irrigation water as it returns to the
Snake River.
The Natural Resources Conservation Service (NRCS) and
other land planning agencies need a tool to predict furrow irrigation
erosion to assess the extent of the problem and to
compare conservation practices applied to irrigated land. An
evaluation of the Water Erosion Prediction Project (WEPP)
model indicated that it could not be used to predict furrow irrigation erosion without substantially adjusting erodibility
parameter values (Bjorneberg et al., 1999). The model also
over-predicted sediment transport capacity resulting in no
predicted sediment deposition on the lower end of fields, although
data and observations document much on-field deposition
(Bjorneberg et al., 1999).
The Idaho NRCS, in consultation with scientists and engineers
at the Northwest Irrigation and Soils Research Laboratory,
Kimberly, Idaho, developed a simple empirical model
for estimating annual irrigation-induced soil loss from furrow
irrigated fields. The SISL (surface irrigation soil loss)
model was developed in 1991 based on over 200 field-years
of data from southern Idaho. This model estimates soil loss
at the end of the furrow and does not account for deposition
or additional erosion that may occur in the drainage ditch at
the end of the field. The only published documentation of this
model is Idaho NRCS Agronomy Technical Note No. 32. Idaho
NRCS uses this model to assess benefits of conservation
practices, such as converting from furrow to sprinkler irrigation,
but this model has not been independently evaluated.
Therefore, the objective of this study was to compare the
SISL model with erosion data collected from furrow irrigated
fields near Kimberly, Idaho and Prosser, Washington
Use of synthetic polymers and biopolymers for soil stabilization in agricultural, construction, and military applications
Get PDFThree relatively new applications for controlling wind and water erosion using polyacrylamide copolymers arc described that
take advantage of their ability to stabilize and add structure to soil. In the first application, low concentrations of anionic, high purity
polyacrylamide (PAM) eliminates sediment in runoff water by more than 90% when added to irrigation water at 10 ppm, or at a rate of
1 to 2 kg ha-1 per irrigation. Lab-furrow tests were utilized to characterize the role of molecular weight. charge, and ion concentrations in
applying PAM during irrigation. In the second application, PAM is applied at construction sites and road cuts at rates of 22.5 kg ha -2
(tenfold higher rates than in irrigation control) resulting in reduction in sediment runoff by 60-85% during (simulated) heavy rains.
Finally, a formulation of PAM mixed with aluminum chlorohydrate and cross-linked poly(acrylic acid) superabsorbent at a ratio of (6:1:1)
has been applied to create helicopter landing pads that minimize dust clouds during helicopter operation. This formulation was specifically
developed to minimize dust clouds during landing of helicopters in fine, arid soils such as those potentially encountered in the Middle
East. A biodegradable alternative to PAM, acid-hydrolyzed cellulose microfibrils, was tested in lab-scale furrows and was less effective
than PAM at similar concentrations, but show promises. Microfibrils reduce sediment run-off in lab-furrow tests by 88% when applied at
eight- to tenfold the concentration of PAM
Nutrient losses from manure and fertilizer applications as impacted by time to first runoff event
Get PDFNutrient losses to surface waters following fertilization contribute to eutrophication. This study was conducted to compare the impacts of
fertilization with inorganic fertilizer, swine (Sus scrofa domesticus) manure or poultry (Gallus domesticus) litter on runoff water quality, and
how the duration between application and the first runoff event affects resulting water quality. Fertilizers were applied at 35 kg P ha-1-, and
the duration between application and the first runoff event varied between 1 and 29 days. Swine manure was the greatest risk to water quality
1 day after fertilization due to elevated phosphorus (8.4 mg P L -1) and ammonium (10.3 mg NH4-N L-1) concentrations; however, this risk
decreased rapidly. Phosphorus concentrations were 2.6 mg L -1 29 days after fertilization with inorganic fertilizer. This research demonstrates
that manures might be more environmentally sustainable than inorganic fertilizers, provided runoff events do not occur soon after application
Forage-induced animal disorders
Get PDFForages are a major source of nutrients for herbivores
around the world. In the United States and Canada about
110 million cattle, 7.4 million sheep, 1.4 million goats,
and 7.4 million horses depend on forages for all or part
of their nutritional needs (Table 45.1). Sometimes the
balance of nutrients or presence of some constituent in
the forage will have negative effects on animal health.
This chapter presents some of these forage-induced
health problems, including bloat, milk fever, grass tetany,
laminitis, nitrate poisoning, mineral imbalances, and effects
of toxic secondary compounds