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Biosolids Application to No-Till Dryland Agroecosytems
Get PDFDryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial nitrogen fertilizer in dryland no-till wheat (Triticum aestivum, L.)-fallow (WF) and wheat-corn (Zea mays, L.)-fallow (WCF) rotations at a site approximately 50 miles east of Denver, CO. We tested if biosolids would produce the same yields and grain phosphorus, zinc, and barium concentrations as an equivalent rate of nitrogen fertilizer, that biosolids-borne phosphorus, zinc, and barium would not migrate below the 4 inch soil depth, and that biosolids application would result in the same quantity of residual nitrate-nitrogen as the equivalent nitrogen fertilizer rate. Biosolids and nitrogen fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain barium due to the soil formation of barium sulfate. Biosolids application produced greater soil nitrate-nitrogen concentrations than nitrogen fertilizer in the 1 to 2 foot and 2 to 3 foot depths for the WF rotation and all but the 2 to 4 inch and the 4 to 5 foot depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source
Characterization of a Basidiomycete Fungus from Stored Sugar Beet Roots
Get PDFEighteen isolates sampled from sugar beet roots associated with an unknown etiology were characterized based on observations of morphological characters, hyphal growth at temperatures ranging from 4 to 28 C, production of phenol oxidases, and sequence analysis of internal transcribed spacer (ITS) and large subunit (LSU) regions of the ribosomal DNA (rDNA). The isolates did not produce asexual or sexual spores, had binucleate hyphal cells with clamp connections, grew from 4 to 22 C with and estimated optimal growth at 14.5 C, and formed a dark brown pigment on potato dextrose or malt extract agar amended with 0.5% tannic acid. Color changes observed when solutions of gum guiac, guiacol, and syringaldzine were applied directly to mycelium grown on these media indicated that all isolates produced phenol oxidases. Sequences of ITS and LSU regions on the rDNA gene from 15 isolates were 99.2 to 100% identical and analysis of sequence data with Maximum Likelihood and Maximum Parsimony suggest that the isolates from sugar beet roots are phylogenetically related to Athelia bombacina, Granulobasidium vellereum, and Cyphella digitalis. High statistical support for both loci under different criteria confirmed that Athelia bombacina was consistently the closest known relative to the sugar beet isolates. Additional taxonomic investigations are needed before species can be clarified and designated for these isolates
Use of a culture-independent approach to characterize aerosolized bacteria near an open-freestall dairy operation
Get PDFAnimal manures are known to harbor a variety of zoonotic pathogens, which are suspected of being transported off-site as aerosols from confined feeding operations. In this study, aerosols were collected using a high-volume sampler downwind from a 10,000 cow open-freestall dairy and nearby fields being sprinkler irrigated with wastewater. DNA extracts were prepared from the aerosol samples, then a region of the16S ribosomal RNA gene was sequenced for bacterial identification and phylogenetic classification. At the dairy and irrigation sites, Proteobacteria was the most abundant phylum, representing 78% and 69% of all sequences, respectively, while Actinobacteria, Bacteroidetes and Firmicutes represented only 10% or less of the sequences. Of the 191 clones sequenced from the dairy aerosol samples, 6 sequences were found to be homologous with uncultured bacteria from cow milk, rumen, and fecal samples. However, none of the sequence matches were affiliated with bacteria known to be pathogenic to otherwise healthy humans. Although our results do suggest a high diversity among the aerosolized bacteria, the sampling strategy employed in this study may not account for the variable nature of bioaerosol emissions
Management of Severe Curly Top in Sugar Beet with Insecticides
Get PDFCurly top caused by Curtovirus species is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. The insecticide seed treatment Poncho Beta has proven to be effective in controlling curly top in sugar beet, but was only evaluated under light to moderate disease pressure. Thus, the insecticide seed treatments Poncho Beta, NipsIt INSIDE, and Cruiser Force were evaluated under severe curly top pressure (6 viruliferous beet leafhoppers per plant) in field studies during the 2010 and 2011 growing seasons on two commercial sugar beet cultivars. In addition, the foliar insecticides Movento, Provado, and Scorpion were also evaluated. The seed treatments and Scorpion reduced curly top symptoms by 33 to 41% (P <0.0001) and increased root yield by 55 to 95% (P <0.0001), sucrose content by 6.5 to 7.2% (P = 0.0013 to <0.0001), and estimated recoverable sucrose by 58 to 96% (P <0.0001) when compared to the untreated check. Movento and Provado did not improve control beyond that provided by Poncho Beta. Even under severe disease pressure 50 to 55 days after planting, neonicotinoid seed treatments can effectively reduce curly top, increase yield, and help protect against early season insect pest pressure
Water balance for a west and midwest watershed.
Get PDFWater use efficiency is a term often applied to irrigated conditions to determine the amount of applied water that is used by crops. Water use in irrigated watersheds can be managed by adjusting irrigation diversions to meet irrigation needs. Precipitation is often the only source of water input in many watersheds, and its rate and timing cannot be controlled. Excess water is often drained from the watershed through surface or subsurface drains to provide suitable conditions for crop growth. The objective of this paper is to compare water balances for the irrigated Upper Snake-Rock (USR) watershed in southern Idaho and the subsurface drained Upper Big Walnut Creek (UBWC) watershed in central Ohio. Irrigation water diverted from the Snake River supplied 80% of the water input into the USR watershed. Precipitation only supplied 10 to 20% of the water in the USR compared to 100% in the UBWC watershed. Potential crop ET was estimated to use 37 to 51% of the total annual water input in the USR watershed and 30 to 55% in the UBWC watershed. The relative volume of water potentially used by crops in these two watersheds was quite similar on an annual basis even though the hydrology throughout the year is quite different
Influence of Sugarbeet Tillage Systems on the Rhizoctonia-Bacterial Root Rot Complex
Get PDFThe Rhizoctonia-bacterial root rot complex in sugarbeet caused by Rhizoctonia solani and Leuconostoc mesenteroides can cause significant yield losses. To investigate the impact of different tillage systems on this complex, field studies were conducted from 2009 to 2011. Split blocks with conventional and strip tillage as main plot treatments were arranged in a randomized complete block design with four replications. Within main plots, there were seven treatments (non-inoculated check and six R. solani AG-2-2 IIIB strains). Regardless of tillage, the roots responded in a similar manner for fungal rot (conventional 8% versus strip 7%), bacterial rot (26% versus 34%), total rot (33% versus 41%), neighboring roots infected (1.7 roots versus 1.5 roots), distance spread (157 mm versus 150 mm), and the number of dead plants (12% versus 14%). Most R. solani strains also responded in a similar manner for disease variables. Strip tillage resulted in 6% more root yield in 2009 (P = 0.087), while conventional tillage resulted in 7% and 27% more root yield in 2010 (P = 0.063) and 2011 (P = 0.012), respectively. The tillage systems influenced disease variables in a similar manner, but more studies will be needed to determine their impact on yield
Rhizoctonia root rot resistance in experimental sugar beet cultivars in Twin Falls County, ID, 2012
Get PDFRhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 experimental sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface rot ranged from 0 to 93% depending on the strain-cultivar combination. Both the number of dead plants and root surface area rotted resulted in significant (P < 0.0004) cultivar differences. Based on Spearman’s rank correlation coefficient, there was always a significant relationship (P < 0.0279) when comparing cultivar performance across all three strains regardless of disease variable. The three most resistant cultivars performed well against all strains and variables, but still had half the root surface area rotted. Additional efforts need to be made to get more resistance to this disease problem in commercial sugar beet cultivars
Nitrogen Availability From Manure in Years Following a One-Time Application
Get PDFManure from the semiarid West’s dairy industries is a rich nutrient source, but its use for crops can be problematic because soil N availability from manure may vary substantially depending on the year of application. Experimental plots established in Idaho on a Portneuf silt loam (coarse silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) included six manure treatments and two non-manure treatments with four replicates. The six manure treatments included combinations of two manure rates, Man-1x (277 lbs total N/ac) and Man-3x (866 lbs total N/ac) applied in the fall either 1, 2, or 3 years previously. The two non-manure treatments were urea fertilizer applied per soil test (Fert) and a control with no amendment. We measured net N mineralization (0-12 in) in the plots using buried bags in 2006, 2007, and 2009 for a sprinkler-irrigated barley, sugarbeet, and dry bean crop, respectively. This resulted in i) two years of net N mineralization data for each manure rate applied 1, 2, or 3 years prior to measurement; and ii) one year of data for each manure rate applied 4 or 5 years previous to the measurement year. A 5-year decay series for each of the two manure rates was derived from functions fitted to the net N mineralization data, expressed as a fraction of total manure-N applied. The decay series (y1-y5) for the manure-1x treatment was 0.23, 0.12, 0.10, 0.09, and 0.08 while that for the manure-3x rate was 0.20, 0.08, 0.05, 0.04, and 0.03. Soil at the 12-to-24-in depth contributed up to 28% of the total N mineralized in the 0-to-60-cm soil layer of manure-amended soils in the 3rd year after application, with lesser amounts contributed in earlier years due to immobilization. The efficacy of N mineralization processes decreased as the manure application increased, thus using a single decay series to predict N availability across a range of manure application rates could lead to substantial estimation errors
Nitrogen Availability and Uptake by Sugarbeet in Years Following Manure Application
Get PDFThe use of solid dairy manure for sugarbeet production is problematic because beet yield and quality are sensitive to deficiencies or excesses in soil N, and soil N availability from manure varies substantially depending on the year of application. Experimental treatments included combinations of two manure rates (0.33 and 0.97 Mg total N ha-1) and three application times, and no manure treatments (control and urea fertilizer). We measured soil net N mineralization and biomass, N uptake, and yields for sprinkler-irrigated sugarbeet. On average, the 1-year-old, low-rate manure, and 1- and 2-year-old, high-rate manure treatments produced 1.2-fold greater yields, 1.1-fold greater estimated recoverable sugar, and 1.5-fold greater gross margins than that of
fertilizer alone. As a group the 1-year-old, low-rate manure, and 2- and 3-year-old, high-rate-manure treatments produced similar cumulative net N mineralization as urea fertilizer; whereas the 1-year-old, high-rate manure treatment provided nearly 1.5-fold more N than either group. With appropriate manure application rates and attention to residual N and timing of sugarbeet planting, growers can best exploit the N mineralized from manure, while simultaneously maximizing sugar yields and profits
sugar beet germplasm evaluated for resistance to rhizomania and fungal growth in storage in Idaho, 2011.
Get PDFResistance to rhizomania is a basic requirement for cultivars’ approval for commercialization. The objectives of this research were to identify germplasm accessions that carry resistance genes to rhizomania and storage root rots. Twenty-one sugar beet (Beta vulgaris L.) germplasm from the USDA-ARS Kimberly sugar beet program and four check cultivars were screened for resistance to Beet necrotic yellow vein virus (BNYVV) during the 2011 growing season and during the 2011/2012 storage period for fungal growth in an indoor storage. The rhizomania evaluation was conducted at the rhizomania nursery in the USDA-ARS North Farm in Kimberly, ID. The crop was managed according to standard cultural practices and pest control. The plots were rated twice (4 weeks apart) for foliar symptom for percentage of plants with yellow, stunted, and upright leaves. At maturity the plants were mechanically topped and hand harvested with the aid of a single-row lifter at maturity. Ten roots per plot were rated for symptom development using a scale of 0-9 (0 = healthy and 9 = dead). Rhizomania symptom development was uniform and other disease problems were not evident in the nursery. The susceptible check was rated at 98 to 99% foliar symptoms and a high root rating. The three resistant checks entries had limited to no foliar symptoms (0 to 5%) and a low root rating (DSI=14 to 20). To evaluate storability, eight roots per plot were placed in a mesh onion bag and placed in an indoor commercial storage facility. After 18 weeks of storage, the roots were evaluated for the percentage of root surface area covered by fungal growth. The resistant checks had a high percentage of fungal growth in storage (67 to 91%) indicating resistance to BNYVV does not preclude roots from storage rot. The BNYVV susceptible check also had considerable fungal growth in storage as expected. Based on previous research, roots show rots and surface fungal growth when are compromised by BNYVV or lack storability. A single entry (K944-62) had BNYVV resistance similar to the resistant checks and additionally had low rot in storage (18%). Other two entries (K944-191 and K39-16) also showed good level of resistance to both BNYVV and storage rots (16 and 17%). This germplasm will be used in the breeding program to identify additional sources of resistance to both BNYVV and storage fungal rot