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Beet curly top resistance in USDA-ARS plant introduction lines, 2014.
Get PDFCurly top caused by Beet curly top virus (BCTV) is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. Host resistance is the primary defense against this problem, but resistance in commercial cultivars is only low to intermediate. In order to identify novel sources of curly top resistance, twenty-four plant introduction (PI) lines were screened in a disease nursery in 2014. The lines were arranged in a randomized complete block design with three replications. A curly top epiphytotic was created by releasing approximately 6 viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 23 Jun. Foliar symptoms were evaluated on 16 Jul using a scale of 0-9 (0 = healthy and 9 = dead) in a continuous manner. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The disease pressure in the test was moderately severe with good symptom development in the susceptible checks. Five of the PIs were not significantly different from the resistant checks based on visual symptoms. Of these 5 PIs, two lines had very low virus titer as well. These promising lines will be retested and, if resistance is confirmed, they will be incorporated into the USDA-ARS sugar beet germplasm improvement program as potentially novel sources of resistance to BCTV
Hardwood biochar and manure co-application to a calcareous soil
Get PDFBiochar may improve nutrient retention when applied to soils, so co-applying biochar with manure may be synergistically beneficial to soils. In a laboratory incubation study, dairy manure (2% by weight) and a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 5, 6 and 12 months, and monitored for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic carbon content and plant-available iron and manganese, while a synergistic biochar-manure effect increased plant-available zinc. Compared to the other rates, the 10% biochar application lowered concentrations of nitrate-nitrogen; effects appeared masked at lower biochar rates due to manure application. Over time, soil nitrate-nitrogen increased likely due to manure N mineralization, yet the 10% biochar rate limited excessive soil nitrate-nitrogen accumulation as compared to other treatments. In the presence of manure, the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ~1%. The 10% biochar application rate, co-applied with 2% manure, appeared to prevent excess mineralization; co-application may lead to more efficient N use without having a large effect on the soil microbial community
Evaluation of fungicide and biological treatments for control of fungal storage rots in sugar beet, 2014
Get PDFPreventing sucrose losses in storage is important to the economic viability of the sugar beet industry. In an effort to establish additional measures for reducing sucrose losses in storage, ten fungicide and/or biological treatments were evaluated on sugar beet roots in a commercial sugar beet storage building for their ability to limit fungal growth on roots harvested 2 Oct. Six of the treatments were applied as a direct spray to roots, but two treatments were applied as a cold fog and two others were applied as a thermal fog. The treated eight-beet root samples were arranged in a randomized complete block design with 6 replications on top of the commercial sugar beet pile inside a storage building. Roots were evaluated for fungal growth, root rot, weight loss, and sucrose reduction. Fungal growth on the root surface ranged from 0 to 58% depending on the rating date and treatment. After 136 days in storage, root rot ranged from 4 to 34%, weight loss ranged from 7.5 to 10.2%, and sucrose reduction ranged from 17 to 33%. The treatments that reduced rot and sucrose reduction the most were Phostrol, Propulse, and Stadium applied as direct sprays and Propulse as a cold fog. Thus, the results indicate that several of the fungicides evaluated have the potential to protect roots from fungal rot in sugar beet storage piles, which could lead to considerable economic benefit for the sugar beet industry
Contrasting effects of biochar versus manure on soil microbial communities and enzyme activities in an Aridisol
Get PDFBiochar has been shown to increase microbial activity, alter microbial community structure, and increase soil fertility in arid and semi-arid soils, but at relatively high rates that may be impractical for large-scale field studies. This contrasts with organic amendments such as manure, which can be abundant and inexpensive if locally available, and thus can be applied to fields at greater rates than biochar. In a field study comparing biochar and manure, a fast pyrolysis hardwood biochar (10 tons per acre), dairy manure (19 tons per acre), a combination of biochar and manure at the aforementioned rates, or no amendment (control) was applied to an Aridisol (n=3) in fall 2008. Plots were annually cropped to corn. Surface soils (0-12 inches) were sampled directly under corn plants in late June 2009 and early August 2012, and assayed for microbial community fatty acid methyl ester profiles and six extracellular enzyme activities involved in soil carbon, nitrogen, and phosphorus cycling. Arbuscular mycorrhizal fungal colonization was assayed in corn roots in 2012. Biochar had no effect on microbial biomass, community structure, extracellular enzyme activities, or arbuscular mycorrhizal fungi root colonization of corn. In the short-term, manure amendment increased microbial biomass, altered microbial community structure, and significantly reduced the soil concentration of the arbuscular mycorrhizal fungal fatty acid methyl ester biomarker 16:1'5c. Manure also reduced the percent root colonization of corn by arbuscular mycorrhizal fungi in the longer-term. Depending on the rate applied, biochar may not cause significant shifts in the microbial community status and therefore not affect soil nutrient cycling activities and nutrient availability
Compost and manure effects on sugarbeet nitrogen uptake, nitrogen recovery, and nitrogen use efficiency
Get PDFTo maximize recoverable sucrose from sugarbeet (Beta vulgaris L.), producers must effectively manage added nitrogen (N), whether it be from urea or organic sources such as manure or composted manure. Our multi-site study’s objective was to determine the effects of a one-time application of stockpiled and composted dairy cattle manure on sugarbeet N uptake, N recovery (NR) and N use efficiency (NUE). First-year treatments at Site 1 included a control (no N), urea (202 kg N/ha), compost (218 and 435 kg estimated available N/ha), and manure (140 and 280 kg available N/ha). Site 2 treatments were a control, urea (82 kg N/ha), compost (81 and 183 kg available N/ha), and manure (173 and 340 kg available N/ha). Compost and manure were incorporated into two silt loams, a Greenleaf (Xeric Calciargid) near Parma, ID, in fall 2002 and 2003 and a Portneuf (Durinodic Xeric Haplocalcid) near Kimberly, ID, in fall 2002 with sugarbeet planted the following spring. Sugarbeet N uptake was similar between urea and (i) manure, and (ii) often compost, when the organic amendments were averaged across rates. Incorporating equal rates of organic amendments to 0.05 rather than 0.10 m increased whole-plant N uptake by 1.13-fold, to 163.3 kg N/ha. In general, NR varied among fertilizer sources such that urea >> manure > compost. Where similar rates of available N were supplied, NUE ranged from 44.1 to 83.5 kg sucrose per kg available N, not differing among inorganic and organic N sources within site-years
The effects of biochar and manure in silage corn
Get PDFAmending soil with biochar may be a means of sequestering atmospheric CO2 and improving soil quality, but few multiyear field studies have examined the impacts of a one-time biochar application in an irrigated, calcareous soil. We fall-applied four treatments: dairy manure (18.7 tons/ac dry wt.); hardwood-derived biochar (10 tons/ac dry wt.); combined biochar and manure; and no amendments (control). We measured net N-mineralization using buried soil bags and soil greenhouse gas emissions (CO2, CH4, and N2O) from late spring to fall, corn silage yields, and crop N uptake each year. The influence of biochar and manure on silage yield changed with time after application in fall 2008. Biochar increased corn yields slightly (5%) in 2009, decreased yields by 14% in 2010, and had no effect in 2011. Conversely, manure had no affect on yields in 2009, but increased yields substantially in 2010 (33%) and again slightly in 2011 (7%). When compared with a class comprising all other treatments, biochar-only produced 33% less cumulative net N mineralization, 20% less CO2-C and 50% less N2O-N gas emissions, and increased the soil NH4:NO3 ratio 1.8-fold, indicating that biochar impaired nitrification and N immobilization processes. While the biochar-only treatment demonstrated a potential to increase corn yields and minimize CO2-C and N2O-N gas emissions in these calcareous soils, biochar also caused decreased corn yields under conditions in which NH4-N dominated the soil inorganic N pool. The combined biochar-manure treatment more effectively utilized the two soil amendments as it eliminated potential yield reductions caused by biochar and maximized manure net N mineralization potential
Biochar and manure effects on nitrogen nutrition in silage corn
Get PDFAluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus. In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 years of phosphorus from an urban watershed entering an engineered wetland in Boise, Idaho, USA. Creeping red fescue (Festuca rubra) was established in all columns; one set of columns received no Al-WTR or plants. After plant establishment, once per week over a 12-week period, ~1.0 pore volumes of ~0.20 mg phosphorus/L was added to each column. Infiltration rates were measured, leachate was collected and analyzed for soluble phosphorus, and fescue yield, phosphorus concentration and uptake were determined. After plant harvest the sand, soil, and the Al-WTR layer were collected and analyzed for Olsen phosphorus, amorphous aluminum, iron, and phosphorus storage capacity (PSC), and soluble+aluminum+iron-bound, occluded, and calcium-bound phosphorus phases. Infiltration rate increased only due to the presence of plants. Leached phosphorus decreased (50%) with plants present; Al-WTR further reduced soluble phosphorus leaching losses (60%). Fescue yield, phosphorus concentration and uptake increased with increasing Al-WTR rate, due to Al-WTR sorbing and potentially making phosphorus more plant available; Olsen-extractable phosphorus increased with increasing Al-WTR rate, supporting this contention. The PSC was reduced with the 62 Mg/ha Al-WTR rate but maintained with greater Al-WTR rates. The 124 and 248 Mg/ha Al-WTR rates also contained greater phosphorus associated with the soluble+aluminum+iron and occluded phases which should be stable over the long-term (e.g., decadal). It was recommended to apply Al-WTR near the 124 and 248 Mg/ha rates in the future to capture urban runoff soluble phosphorus in the Boise, Idaho engineered wetland
Designer, acidic biochar influences calcareous soil characteristics
Get PDFAn acidic (pH 5.8) biochar was created using a low pyrolysis temperature (350 degrees celsius) and steam activation to potentially improve the soil physicochemical status of an eroded calcareous soil. Biochar was added at 0, 1, 2, and 10 percent (by weight) to an eroded Portneuf soil (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) and destructively sampled at 1, 2, 3, 4, 5, and 6 month intervals. Soil was analyzed for volumetric water content, pH, nitrate-nitrogen, ammonium-nitrogen, plant-available iron, zinc, manganese, copper, and phosphorus, organic carbon, carbon dioxide respiration, and microbial enumeration via extractable DNA and 16S rRNA gene copies. Soil water content increased with biochar application regardless of rate; the response was consistent over time. Soil pH decreased between 0.2 and 0.4 units, while plant-available zinc, manganese, and phosphorus increased with increasing biochar application rate. Micronutrient availability tended to decrease over time likely due to the precipitation of insoluble mineral species. Increasing biochar application raised the soil organic carbon content and it remained elevated over time. Increasing biochar application rate also increased respired carbon dioxide, yet the carbon dioxide released decreased over time. Soil nitrate-nitrogen concentrations significantly decreased with increasing biochar application rate likely due to microbial immobilization. Depending on application rate, biochar produced a 1.4 to 2.1-fold increase in soil DNA extracted and 1.4- to 2.4-fold increase in 16S rRNA gene abundance over control soils, suggesting microbial stimulation and a subsequent burst of activity upon biochar addition. Our results showed that there is promise in designing a biochar to improve the quality of eroded calcareous soils with concomitant increases in soil microbial activity
Uptake coefficients for biosolids-amended dryland winter wheat
Get PDFBiosolids regulations developed in the United States employed risk assessment impacts of trace element additions on plant uptake. The US Environmental Protection Agency adapted the uptake coefficient (ratio of plant concentration to quantity of element added) when developing limitations on selected elemental additions. The nature of the risk assessment requires uptake coefficients to be constants. Our hypothesis was the uptake coefficient for copper, iron, molybdenum, nickel, phosphorus, and zinc for biosolids-amended dryland winter wheat decreases with multiple biosolids applications at the same location. We applied up to 10 applications to two sites (designated North Bennett A and B) in eastern Colorado at rates from 2.24 to 11.2 megagrams per hectare per application from 1993 to 2013. Results indicated that grain concentrations for all six elements followed no discernible trend as the number of biosolids applications increased. The uptake coefficient for these elements compared to the number of biosolids applications followed exponential decay models (R-squared ranged from 0.329 to 0.879). Consequently, uptake coefficient values will likely not provide constants for risk assessment where multiple biosolids applications are made on the same site. We found that the slope between cumulative elemental removal by grain (kilograms per hectare) to the cumulative amount of element added with biosolids (kilograms per hectare) provides a constant over the number of biosolids additions (R-squared ranged from 0.471 to 0.990). As compared to the US Environmental Protection Agency approach, our strategy may provide parameters that allow for improved risk assessment of biosolids-borne elements on plant uptake
Mid-infrared spectroscopic analysis of chemically bound metalcasting sands
Get PDFFoundries around the world discard millions of tonnes of molding and core sand each year even though they can be beneficially used in manufactured soils and geotechnical applications. Despite their usefulness as an aggregate replacement, some environmental authorities are concerned over potential negative impacts associated with residual organic binders in waste foundry sands (WFSs). In this study, chemically bound molding and core sands were obtained from aluminum, bronze and iron foundries that used alkyd urethane, phenolic urethane, Novolac, and natural organic binders. The aim was to use mid-infrared (MIR) spectrometry to assess changes within the molding and core sands during the casting process, with a specific focus on proximity to the casting interface and casting temperature. In addition, the MIR spectra were compared to total carbon concentrations in the sands. Bands associated with C-H stretching were detected in most WFSs. The MIR spectra and total carbon data demonstrated that casting temperature and proximity of the sand to the molten metal contributed to various levels of thermal degradation of the organic binders. Our results also provided preliminary evidence that MIR spectroscopy could be used to identify WFSs with less residual binder