1816 research outputs found
Sort by
Evaluation of sugar beet germplasm and plant introductions response to rhizomania and storability in Idaho, 2008
Get PDFSugar beet germplasm, wild beta, and commercial check cultivars were evaluated in a commercial
field (near Declo, ID ). This field was sprinkler-irrigated and winter wheat was grown in the previous year.
The field trial relied on natural inoculum for rhizomania development. The seed was treated with
clothianidin (2.1 oz a.i. per 100,000 seed) to limit the influence of pests and curly top. The plots were
planted on 15 Apr 08 to a density of 142,560 seeds/A, and thinned to 47,520 plants/A on 12 Jun. Plots
were single rows (22-in. row spacing) and 10 ft long. The experimental design was a randomized complete
block design with eight replications per entry. The field was cultivated on 13 Jun 08. The crop was
managed by the grower according to standard cultural practices. The roots were mechanically topped and
lifted on 29 Sep 08. The first ten roots in each plot were scored for disease severity index (DSI) using a
scale of 0-9 (0 = healthy and 9 = dead). To evaluate germplasm for storability, eight roots from each plot
from 4 replications were placed in a mesh onion bag and held in an indoor commercial sugar beet storage
facility set to hold 35°F for 90 days (until 1 Feb 09). The roots were evaluated for the percentage of
surface area covered by fungal growth (an undescribed Basidiomycete that correlates with sugar loss in
storage). Data were analyzed using the general linear models procedure (Proc GLM-SAS), and Fisher’s
protected least significant difference was used for mean comparisons
Qualitative and quantitative methodologies for determination of airborne microorganisms at concentrated animal-feeding operations
Get PDFThe generation of airborne microorganisms
from concentrated animal-feeding operations (CAFOs) is a
concern from a human and animal health perspective. To
better understand the airborne microorganisms found in
these environments, a number of collection and analytical
techniques have been utilized and will be discussed in this
review. The most commonly used bioaerosol collection
method is the liquid impingement format, which is suitable
with a number of culture-based and non-culture molecularbased
approaches, such as polymerase chain reaction.
However, the vast majority of airborne microorganism
studies conducted at CAFOs utilize culture-based analyses.
Because of the limitations often associated with culturebased
analyses, we focused our discussion on the application
of molecular-based techniques to identify and/or
quantify microorganisms, as they have promising application
in bioaerosol research. The ability to rapidly characterize
airborne microorganisms will help to ensure
protection of public and environmental health
Sulfate Foot Baths on Dairies and Crop Toxicities
Get PDFA rising concern with the application of dairy wastes to agricultural fields is the accumulation of
copper (Cu) in the soil. Copper sulfate (CuSO4) from cattle footbaths is washed out of dairy
barns and into wastewater lagoons. The addition of CuSO4 baths can increase Cu concentration
significantly in manure slurry, from approximately 5.0 grams per 1,000 liters to 90.0 grams per
1,000 liters. The Cu-enriched dairy waste is then applied to agricultural crops, thus raising
concerns about how soils and plants are impacted by these Cu additions
Interaction of calcium and phytate in broiler diets: 2. Effects on total and soluble phosphorus excretion
Get PDFDietary Ca has been reported to influence the amount of phytate excreted from broilers and affect the solubility of P in excreta. To address the effects of dietary Ca and phytate on P excretion, 12 dietary treatments were fed to broilers from 16 to 21 d of age. Treatments consisted of 3 levels of phytate P (0.10, 0.24, and 0.28%) and 4 levels of Ca (0.47, 0.70, 0.93, and 1.16%) in a randomized complete block design. Feed phytate concentrations were varied by formulating diets with 3 different soybean meals (SBM): a low-phytate SBM, a commercial SBM, and a high phytate Prolina SBM having phytate P concentrations of 0.15 to 0.51%. Fresh excreta was collected from cages during 2 separate 24-h periods; collection I commenced after the start of dietary treatments (16 to 17 d) and collection II followed a 3-d adaptation period (19 to 20 d). Ileal samples were also collected at 21 d. Excreta samples were analyzed for total P, water soluble P (WSP), and phytate P, whereas ileal samples were analyzed for total P and phytate P. Results indicated that excreta total P could be reduced by up to 63% and WSP by up to 66% with dietary inclusion of low-phytate SBM. There was a significant effect of dietary Ca on both the excreta WSP and the ratio of WSP:total P. As dietary Ca increased, the excreta WSP and WSP:total P decreased, with the effects being more pronounced following a dietary adaptation period. There was a linear relationship between the slope of the response in WSP to dietary Ca and feed phytate content for excreta from collection II (r(2) = 0.99). There was also a negative correlation between excreta phytate concentration and excreta WSP during both excreta collections. The response in WSP to dietary manipulation was important from an environmental perspective because WSP in excreta has been related to potential for off-site P losses following land application
Matrix based fertilizers reduce nitrogen and phosphorus leaching in three soils
Get PDFWe compared the efficacy of matrix based fertilizers (MBFs) formulated to reduce NO3-, NH4+, and total phosphorus (TP) leaching, with Osmocoate 14-14-14, a conventional commercial slow release fertilizer (SRF) and an unamended control in three different soil textures in a greenhouse column study. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF 1) to more moderately bound (MBF 2) and more tightly bound compounds (MBF 3) mixed with Al(SO4)3H2O and/or Fe2(SO4)3 and with high ionic exchange compounds starch, chitosan and lignin. When N and P are released, the chemicals containing these nutrients in the MBF bind N and P to a Al(SO4)3H2O and/or Fe2(SO4)3 starch-chitosan-lignin matrix. One milligram (8000 spores) of Glomus intradices was added to all formulations to enhance nutrient uptake. In all three soil textures the SRF leachate contained a higher amount of NH4+, NO3- and TP than leachate from all other fertilizers. In all three soils there were no consistent differences in the amount of NH4+, NO3- and TP in the MBF leachates compared to the control leachate. Plants growing in soils receiving SRF had greater shoot, root and total biomass than all MBFs regardless of Al(SO4)3H2O or Fe2(SO4)3 additions. Arbuscular mycorrhizal infection in plant roots did not consistently differ among plants growing in soil receiving SRF, MBFs and control treatments. Although the MBFs resulted in less plant growth in this experiment they may be applied to soils growing plants in areas that are at high risk for nutrient leaching to surface waters
Transgenic sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2007
Get PDFThirty-two transgenic (glyphosate resistant) and six conventional commercial sugar beet cultivars were evaluated in
a commercial sprinkler-irrigated sugar beet field near Rupert, ID where winter wheat was grown in 2006. The field trial
relied on natural infection for rhizomania development. The plots were planted on 3 Apr 07 to a density of 142,560 seeds/A,
and thinned to 47,520 plants/A on 23 May. Plots were four rows (22-in. row spacing) and 24 ft long. The experimental
design was a randomized complete block design with four replications per entry. The crop was managed according to
standard cultural practices. The roots were mechanically topped and the center two rows were collected with a mechanical
harvester on 26 Sep. At harvest the roots were evaluated for rhizomania (using a scale of 0-9, 0 = healthy and 9 = dead).
The percent sucrose at harvest was established based on two 8-root samples from each plot. The samples were submitted to
the Amalgamated Tare Lab (determined percent sucrose, conductivity, nitrates, and tare). At harvest, eight roots per plot
were also placed in a mesh onion bag, weighed, and placed in an indoor commercial sugar beet storage facility on 27 Sep 07
set to hold 35°F. On 1 Feb 08, the roots were evaluated for the percentage of surface area covered by fungal growth (an
undescribed basidiomycete that correlates with sucrose loss in storage). On 4 Mar 08 roots were retrieved after 160 days in
storage and evaluated for weight and percent sucrose (via gas chromatography). To establish percent reduction in sucrose at
harvest versus storage only samples from the same plots were compared. Data were analyzed using the general linear models
procedure (Proc GLM-SAS), and Fisher’s protected least significant difference was used for mean comparisons
Potential runoff and erosion comparison of center pivot sprinklers on three Idaho soils
Get PDFThe operational characteristics of center pivot sprinklers are well documented but few
studies have been conducted to evaluate the effects that operating characteristics of a particular
sprinkler have on infiltration, runoff, and erosion of specific soil types. The objective of this
study was to evaluate potential runoff and erosion from common commercial center pivot
sprinklers on three widely distributed, south central Idaho soils. A modified commercial
irrigation boom system was used to emulate center pivot irrigation on experimental runoff plots.
Sprinklers used in the study were: 1) Nelson R3000 with brown plate, 2) Nelson R3000 with red
plate, 3) Nelson S3000 with purple plate, and 4) Senninger I-Wob with standard 9-groove plate.
There were significant differences in runoff and erosion rates between sprinkler types for the
soils tested and experimental conditions. The I-Wob exhibited the highest overall runoff and
erosion rates and the R3000 sprinklers exhibited the lowest rates for the three soils tested. In
general, sprinkler types that visually appear to more uniformly distribute sprinkler droplets over
the wetted area with respect to time exhibited the highest runoff and erosion rates. The relative
differences in runoff between the sprinklers tested for the three soils were not directly
proportional to droplet kinetic energy. This outcome is in conflict with conventional theory on
soil surface sealing from droplet impact
Carbon and nitrogen stable isotope ratios can estimate anionic polyacrylamide degradation in soil
Get PDFWater-soluble anionic polyacrylamide (PAM) is applied to millions of hectares worldwide as a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1 to 2 kg ha− 1 (i.e., 1 to 10 g m− 3) in furrow water. PAM degradation has not directly been measured in soil. We tested the ability of stable isotopes of C and N at natural abundance to estimate PAM degradation rates. Values of δ13C were related to anionic PAM concentration in a positive curvilinear relationship in a low-C, low-N, Durinodic Xeric Haplocalcid (Portneuf series) soil. The other soils with higher organic C or N concentrations did not show significant relationships between PAM concentrations and δ13C values. The δ15N values were not related to anionic PAM concentration in any of the soils tested. When 2691 active ingredient (ai) kg PAM ha− 1 was applied to the Durinodic Xeric Haplocalcid soil, 49% and 74% of the PAM was degraded after 6 and 12 yr respectively. When 5382 kg ai PAM ha− 1 was applied to the Durinodic Xeric Haplocalcid soil, 13% was degraded after 6 yr, and 73% of the PAM was degraded after 12 yr. We calculated PAM degradation rate based on δ13Cfor the Durinodic Xeric Haplocalcid soil to be 9.8% yr− 1. Further testing using labeled PAM is necessary to estimate degradation rates in higher C soils, and to determine what portion of the C is released from decomposing PAM is emitted to the atmosphere, incorporated into soil organic matter and living microbial biomass
Biosolids application to no-till dryland and crop rotations: 2006 results
Get PDFBiosolids recycling on dryland winter wheat (Triticum aestivum, L.) can supply a reliable, slow‐release source of nitrogen (N) and organic material (Barbarick et al., 1992). Barbarick and Ippolito (2000, 2007) found that continuous application of biosolids from the Littleton/Englewood, CO wastewater treatment facility to dryland winter wheat‐fallow rotation provides 16 to 18 lbs N per dry ton. This research involved tilling the biosolids into the top 8 inches of soil. A new question related to soil management in a biosolids beneficial‐use program is: How much N would be available if the biosolids were surface‐applied in a no‐till dryland agroecosystem with winter wheat‐fallow (WF) and winter wheat‐corn (Zea mays, L.)‐fallow (WCF) crop rotations?
Our objective was to compare agronomic rates of commercial N fertilizer to an equivalent rate of biosolids in combination with WF and WCF crop rotations. Our hypotheses were that biosolids addition, compared to N fertilizer, will:
1. Produce similar crop yields;
2. Not differ in grain P, Zn, and Cu levels (Ippolito and Barbarick, 2000) or soil P, Zn, and Cu AB‐DTPA extractable concentrations, a measure of plant availability (Barbarick and Workman, 1987); and
3. Not affect soil salinity (electrical conductivity of saturated soil‐paste extract, EC) or soil accumulation of nitrate‐N (NO3‐N)
Conservation practice effectiveness in the irrigated Upper Snake/Rock Creek watershed
Get PDFThe Upper Snake River/Rock Creek Conservation Effects Assessment Project was initiated in 2005 to determine the effectiveness of conservation practices in an irrigated watershed. Our objectives were to determine water and salt balances and water quality effects of using sprinkler rather than furrow irrigation in the Twin Falls irrigation tract in southern Idaho. Data from the current study were compared with earlier studies conducted from 1968 to 1971. Irrigation water diverted from the Snake River supplied 73% and 83% of the hydrologic input to this 82,000 ha (202,000 ac) watershed in 2005 and 2006, respectively, with approximately 40% flowing back to the Snake River through furrow irrigation runoff, unused irrigation water, and subsurface drainage. Net suspended sediment loss decreased from 460 kg ha–1 (400 lb ac–1) during the 1971 irrigation season to 220 kg ha–1 (190 lb ac–1) in 2005 and 10 kg ha–1 (9 lb ac–1) in 2006 by switching from furrow to sprinkler irrigation, applying polyacylamide, and installing sediment ponds. The relative amount of sprinkler irrigation in a subwatershed did not correlate with the total loss of suspended sediment for July 2005 and 2006 (r = 0.12). The lack of correlation was primarily due to extremely high sediment concentrations in two of the five subwatersheds, possibly due to furrow irrigation management. Two potential concerns identified during this initial analysis were an accumulation of total salts in the watershed and increased nitrate concentrations in four return flow streams compared to earlier studies. Future analyses will determine the effects of specific practices with this watershed