Effectiveness of flue gas desulfurization gypsum in reducing phosphorus solubility in poultry litter when applied as an in-house amendment.

Phosphorus (P) runoff from agricultural lands receiving poultry litter (PL) poses a major environmental challenge. Application of flue-gas-desulfurization (FGD)-gypsum produced from coal power plants in agricultural lands has shown promise to reduce P losses. However, no information is available about the effectiveness of FGD-gypsum addition in reducing P solubility when applied as an in-house amendment. Hence, the objectives of this study were to understand a) effectiveness of FGD-gypsum as a litter amendment in reducing P loss risk; and b) how FGD-gypsum amendment in PL alters the distribution of P forms. Broiler chickens were raised for five flocks in seven individual litter treatments replicated four times in a randomized complete block design. Based on the FGD-gypsum addition, the PL treatments were broadly classified as FGD-gypsum treated and untreated. Toxic metal concentrations were analyzed in FGD-gypsum as well as the treatments. Sequential water extractions were performed to understand P solubility. Litter P fractionation was performed to identify bioavailable P (Water-P), labile P (NaHCO3-P), aluminum/iron chemisorbed P (NaOH-P), and mineral occluded P (HCl-P). Results indicated significantly higher soluble P in all untreated than in all FGD-gypsum treated litters in the initial water extraction. The FGD-gypsum treated litters reduced soluble P by 58 to 67% in the 1st water extraction compared to untreated litters. Fractionation study revealed lower proportion of Water-P and higher proportion of NaHCO3-P and HCl-P in all FGD-gypsum treated than in untreated litters. This study suggests reuse of FGD-gypsum in broiler houses can help reduce P mobility without any toxic metals concerns.

Gold Dental Implant-Induced Oral Lichen Planus.

Lichen planus is a chronic inflammatory cutaneous and mucosal disease mostly affecting middle-aged individuals. The etiology of lichen planus is unknown, but current literature suggests that it is an altered immune response characterized by dysregulated T-cell activation and subsequent inflammation which can be associated with conditions like allergic contact dermatitis and hepatitis C. Additionally, heavy metals like lead, tin, arsenic, and bismuth can create inflammatory and allergic reactions that can predispose to the formation of lichen planus. This report examines the case of a 64-year-old female with longstanding oral lichenoid lesions with superimposed Wickham's striae, allergic skin reactions to several medications, and a history of receiving gold-containing dental implants. As a result of her history and subsequent allergy testing, she was found to have a gold allergy. The constant mucosal irritation from her dental implants likely was associated with the development of her oral lesions, which were confirmed to be oral lichen planus. She was recommended to apply triamcinolone 0.1% ointment to her oral lesions and to follow up with her dentist for evaluation of her filings. Further, it was recommended she replaces the dental crowns with compounds lacking gold to decrease the persistent irritation. This case represents the first such instance of gold dental fillings directly having an appreciable role in the development of oral lichen planus.

Moisture content and aeration control mineral nutrient solubility in poultry litter.

Poultry litter waste is typically land-applied as a soil amendment but repeated application in the vicinity of poultry houses has led to phosphorus accumulation in soil. Such application can also lead to runoff that causes eutrophication. Most farmers store litter under dry conditions or compost the litter prior to land application, but it is not clear if these approaches are best from a nutrient management-perspective. The objective of this study was to investigate the effects of moisture content and active aeration on soluble mineral forms of nitrogen and phosphorus in poultry litter incubated for roughly one month. Mineral forms of nutrients are immediately plant-available upon field application and also most conducive to low-cost stripping and recovery methods. Litters were incubated at 50% and 70% moisture content with and without active aeration. Litter aeration led to significant ammonia losses and a consequent decline in litter pH but it had no effect on phosphate solubility. Moisture content during litter incubation governed the levels of plant-available phosphate and nitrification. High (70%) moisture led to 41%-78% higher plant-available phosphate (4.2-4.8 mg/g litter) compared to litters with 50% moisture content (2.7-3.0 mg/g litter). In contrast, the 50% moisture litters experienced 5-6 fold higher levels of nitrification (0.11-0.12 mg NO3-N/g litter) than litters with 70% moisture content (0.02 mg NO3-N/g litter), regardless of aeration. The implication is that lower-moisture litter storage is likely best for field application because phosphate is less soluble under neutral-alkaline conditions and therefore less likely to end up in runoff. In contrast, higher-moisture litter storage may be amenable to low-cost processes to leach and recover phosphate from litter.

Understanding the environmental impact of phosphorus in acidic soils receiving repeated poultry litter applications.

With rising global demand of poultry products, a surge in poultry production would warrant safe disposal of waste byproducts such as poultry litter (PL). A dilemma exists over environmental phosphorus (P) loss risk and agronomic utilization of PL in highly weathered soils with high P fixation capacity. The objective of this study was to determine P forms and their distribution in highly weathered Piedmont soils located in high density poultry operation (HDPO) areas and evaluate environmental P loss risk using soil P storage capacity (SPSC) approach. Soil samples from agricultural fields with 10 ± 2 years PL application history were collected from surface (0-15 cm) and subsurface (15-30 cm) depths. Approximately 64 ± 11% of total P was in non-reactive P (NRP) form, 35 ± 19% in moderately reactive P (MRP) forms, and < 1% in highly reactive P (HRP) form. Phosphorus sorption index (PSI) was higher in subsurface (316 L kg-1) compared to surface soils (150 L kg-1). The SPSC calculated based on a distinct soil threshold P saturation ratio (PSR; ratio of P/[Al + Fe], all elements expressed in moles) was higher in subsurface (17 mg kg-1) than surface (-150 mg kg-1) soils. Repeated application of PL resulted in P saturation of surface soils (SPSC<0) and represents a source of P to the environment. The NRP form decreased, and MRP forms increased when a) soil test P (STP) rating transitioned from low to extremely high, and b) SPSC changed from positive to negative. Results indicate that P release in soil solution is predominantly controlled by buffering action of MRP forms since HRP was minimal and NRP is mostly unavailable in highly weathered soils. A holistic approach that includes STP for maintaining agronomic productivity along with SPSC to minimize environmental P loss risk will be desirable for sustainable management of PL in HDPO.

Aerobic bacterial pretreatment to overcome algal growth inhibition on high-strength anaerobic digestates.

Coupling anaerobic digestion and algae cultivation has attracted attention as a sustainable means of treating high-strength wastewaters. In such a scenario, nutrients from the liquid anaerobic digestate are used by algae to produce biomass. However, use of full-strength digestate results in poor algal growth and nutrient removal. Most researchers have overcome this challenge by diluting digestate 10-30 fold prior to algae growth but such dilution rates demand large amounts of fresh water, posing challenges for scale-up. The objectives of this study were to 1) assess whether ammonium, turbidity, and heavy metals in digestate were the primary sources of inhibition for a highly-nutrient tolerant strain of Chlorella sorokiniana, and, 2) develop a biological pretreatment strategy to overcome algal growth inhibition on full strength digestate. Ammonia toxicity, turbidity, and heavy metals have been commonly hypothesized as the source of algal growth inhibition, but our results showed that these factors were not critical inhibitors of C. sorokiniana. Dose response studies showed that C. sorokiniana could grow robustly on 3,500 mg/L ammonium. Regardless, full strength digestates of wastewater sludge and food waste were very inhibitory to C. sorokiniana. We utilized a pretreatment approach using activated sludge which led to robust algal growth on full-strength digestate. High growth rates of 250-500 mg/L/d were achievable on pretreated digestates despite very high ammonium levels of ∼2,000 mg/L. Pretreating digestate also led to significantly faster algal nutrient uptake compared to untreated digestate (p < 0.001).

Projected heat stress challenges and abatement opportunities for U.S. milk production.

Cost-effective heat mitigation strategies are imperative for maintaining milk production and dairy farm profitability in the U.S. with projected climate change. This study investigated the cost-effectiveness of four heat abatement strategies, including Minimal (open barn or shading), Moderate (forced ventilation), High (fans and misting), and Intense (air conditioning). Heat stress and subsequent impacts on milk production per cow were predicted across nine climatic regions in the U.S. for early (2015 to 2034), mid (2045 to 2064) and late (2081 to 2100) 21st century, using downscaled climate projections. Heat abatements were used to adjust predicted milk production losses and illustrate the potential to reduce milk production losses due to heat stress. Economic analysis included a cost-benefit ratio calculation associated with the implementation of each heat abatement. Results showed that milk production losses were expected to accelerate across the U.S. at a mean rate of 174±7 kg/cow/decade, with the fastest rate in the Southeast region. Relative to Minimal heat abatement, Moderate, High, and Intense heat abatements increased annual milk production per cow by 3%, 4%, and 6% during early-21st century, 3%, 6%, and 11% during mid-21st century, and 3%, 8%, and 21% during late-21st century, respectively. The cost effectiveness of different heat abatement strategies generally increased with subsequently stronger heat abatements. In mid- and late-21st century, mean annual net values of High and Intense heat stress abatement implementation approached -$30 to $190 /cow and -$20 to $590 /cow, respectively, with the largest net annual benefit in late-21st century under Intense abatement. Findings from the study demonstrate the value of using downscaled climate projections to shed light on local and regional strategies to abate heat stress on cattle and mitigate potential milk production losses due to climate change.

Leaching and anaerobic digestion of poultry litter for biogas production and nutrient transformation.

Anaerobic digestion of poultry litter is a potentially sustainable means of stabilizing this waste while generating biogas. However, technical challenges remain including seasonality of litter production, low C/N ratios, limited digestibility of bedding, and questions about transformation of nutrients during digestion. This study investigated biogas production and nutrient transformations during anaerobic digestion of poultry litter leachate and whole litter. Use of fresh litter collected from within the house was also compared to waste litter cake that was stored outdoors on the farm. The results showed that litter leachates had higher biomethane potential (0.24-0.30 L/gVS) than whole litter (0.15-0.16 L/gVS) and the insoluble bedding material left after leaching (0.08-0.13 L/gVS). Leachates prepared from waste litter cake had lower uric acid and higher acetic acid concentrations than fresh litter indicating that decomposition had occurred during storage. Consequently, waste litter cake had faster initial biogas production but lower final biogas yields compared to fresh litter. In all reactors, uric and acetic acids were completely consumed during digestion, phosphate levels decreased but ammonium levels increased. The results demonstrate that poultry litter leachate is amenable to digestion despite a low C/N ratio and that the remaining insoluble bedding material has been partially stripped of its nutrients. Moreover, litter can be stored prior to digestion but some losses in biomethane potential should be expected due to decomposition of organics during storage.

Projected climate and agronomic implications for corn production in the Northeastern United States.

Corn has been a pillar of American agriculture for decades and continues to receive much attention from the scientific community for its potential to meet the food, feed and fuel needs of a growing human population in a changing climate. By midcentury, global temperature increase is expected to exceed 2°C where local effects on heat, cold and precipitation extremes will vary. The Northeast United States is a major dairy producer, corn consumer, and is cited as the fastest warming region in the contiguous U.S. It is important to understand how key agronomic climate variables affect corn growth and development so that adaptation strategies can be tailored to local climate changes. We analyzed potential local effects of climate change on corn growth and development at three major dairy locations in the Northeast (Syracuse, New York; State College, Pennsylvania and Landisville, Pennsylvania) using downscaled projected climate data (2000-2100) from nine Global Climate Models under two emission pathways (Representative Concentration Pathways (RCP) 4.5 and 8.5). Our analysis indicates that corn near the end of the 21st century will experience fewer spring and fall freezes, faster rate of growing degree day accumulation with a reduction in time required to reach maturity, greater frequencies of daily high temperature ≥35°C during key growth stages such as silking-anthesis and greater water deficit during reproductive (R1-R6) stages. These agronomic anomalies differ between the three locations, illustrating varying impacts of climate change in the more northern regions vs. the southern regions of the Northeast. Management strategies such as shifting the planting dates based on last spring freeze and irrigation during the greatest water deficit stages (R1-R6) will partially offset the projected increase in heat and drought stress. Future research should focus on understanding the effects of global warming at local levels and determining adaptation strategies that meet local needs.

Environmental Nitrogen Losses from Commercial Crop Production Systems in the Suwannee River Basin of Florida.

The springs and the Suwannee river of northern Florida in Middle Suwanee River Basin (MSRB) are among several examples in this planet that have shown a temporal trend of increasing nitrate concentration primarily due to the impacts of non-point sources such as agriculture. The rate of nitrate increase in the river as documented by Ham and Hatzell (1996) was 0.02 mg N L-1 y-1. Best management practices (BMPs) for nutrients were adopted by the commercial farms in the MSRB region to reduce the amounts of pollutants entering the water bodies, however the effectiveness of BMPs remains a topic of interest and discussion among the researchers, environmental administrators and policy makers about the loads of nitrogen entering into groundwater and river systems. Through this study, an initiative was taken to estimate nitrogen losses into the environment from commercial production systems of row and vegetable crops that had adopted BMPs and were under a presumption of compliance with state water quality standards. Nitrogen mass budget was constructed by quantifying the N sources and sinks for three crops (potato (Solanum tuberosum L.), sweet corn (Zea mays L.) and silage corn (Zea mays L.)) over a four year period (2010-2013) on a large representative commercial farm in northern Florida. Fertilizer N was found to be the primary N input and represented 98.0 ± 1.4, 91.0 ± 13.9, 78.0 ± 17.3% of the total N input for potato, sweet corn, and silage corn, respectively. Average crop N uptake represented 55.5%, 60.5%, and 65.2% of the mean total input N whereas average mineral N left in top 0.3 m soil layer at harvest represented 9.1%, 4.5%, and 2.6% of the mean total input N. Mean environmental N losses represented 35.3%, 34.3%, and 32.7% of the mean total input N for potato, sweet corn, and silage corn, respectively. Nitrogen losses showed a linear trend with increase in N inputs. Although, there is no quick fix for controlling N losses from crop production in MSRB, the strategies to reduce N losses must focus on managing the crop residues, using recommended fertilizer rates, and avoiding late-season application of nitrogen.

Unlinking an lncRNA from Its Associated cis Element.

Long non-coding (lnc) RNAs can regulate gene expression and protein functions. However, the proportion of lncRNAs with biological activities among the thousands expressed in mammalian cells is controversial. We studied Lockd (lncRNA downstream of Cdkn1b), a 434-nt polyadenylated lncRNA originating 4 kb 3' to the Cdkn1b gene. Deletion of the 25-kb Lockd locus reduced Cdkn1b transcription by approximately 70% in an erythroid cell line. In contrast, homozygous insertion of a polyadenylation cassette 80 bp downstream of the Lockd transcription start site reduced the entire lncRNA transcript level by >90% with no effect on Cdkn1b transcription. The Lockd promoter contains a DNase-hypersensitive site, binds numerous transcription factors, and physically associates with the Cdkn1b promoter in chromosomal conformation capture studies. Therefore, the Lockd gene positively regulates Cdkn1b transcription through an enhancer-like cis element, whereas the lncRNA itself is dispensable, which may be the case for other lncRNAs.

Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR.

Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB) is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L.) production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N) loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1) N) of the total input N (310 to 349 kg ha(-1) N). The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1) N) and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn). The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.