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The study of interrelationships among soil health indicators is important for (i) achieving better understanding of nutrient cycling, (ii) making soil health assessment cost-effective by eliminating redundant indicators, and (iii) improving nitrogen (N) fertilizer recommendation models. The objectives of this study were to (i) decipher complex interrelationships of selected chemical, physical, and biological soil health indicators in pastures with history of inorganic or broiler litter fertilization, and (ii) establish associations among inorganic N, potentially mineralizable N (PMN), and soil microbial biomass (SMBC), and other soil health indicators. In situ soil respiration was measured and soil samples were collected from six beef farms in 2017 and 2018 to measure selected soil health indicators. We were able to establish associations between easy-to-measure active carbon (POXC) vs. PMN (R2 = 0.52), and N (R2 = 0.43). POXC had a noteworthy quadratic relationship with N and nitrate, where we found dramatic increase of N and nitrate beyond an inflection point of 500 mg kg−1 POXC. This point may serve as threshold for soil health assessment. The relationships of loss-on-ignition (LOI) carbon with other soil health indicators were discernable between inorganic- and broiler litter-fertilized pastures. We were able to establish association of SMBC with other soil variables (R2 = 0.76) and there was detectable difference in SMBC between inorganic-fertilized and broiler litter-fertilized pastures. These results could be useful for cost-effective soil health assessment and optimization of N fertilizer recommendation models to improve N use efficiency and grazing system sustainability.
Subash Dahal; Dorcas Franklin; Anish Subedi; Miguel Cabrera; Laura Ney; Brendan Fatzinger; Kishan Mahmud. Interrelationships of Chemical, Physical and Biological Soil Health Indicators in Beef-Pastures of Southern Piedmont, Georgia. Sustainability 2021, 13, 4844 .
AMA StyleSubash Dahal, Dorcas Franklin, Anish Subedi, Miguel Cabrera, Laura Ney, Brendan Fatzinger, Kishan Mahmud. Interrelationships of Chemical, Physical and Biological Soil Health Indicators in Beef-Pastures of Southern Piedmont, Georgia. Sustainability. 2021; 13 (9):4844.
Chicago/Turabian StyleSubash Dahal; Dorcas Franklin; Anish Subedi; Miguel Cabrera; Laura Ney; Brendan Fatzinger; Kishan Mahmud. 2021. "Interrelationships of Chemical, Physical and Biological Soil Health Indicators in Beef-Pastures of Southern Piedmont, Georgia." Sustainability 13, no. 9: 4844.
Beans are often grown in regions with climates that are susceptible to drought during the cultivation period. Consequently, it is important to identify bean accessions tolerant to drought conditions and assess the effect of drought on seeds’ nutraceutical properties. This study evaluated the effect of drought during different development stages (NES = never stressed; ALS = always stressed; SBF = stressed before flowering; SAF = stressed after flowering) on the yield and nutraceutical properties of six local bean varieties: Fasolo del Diavolo, Gialet, Posenati, Secle, D’oro, and Maron. Analysis of variance indicated that Gialet was not significantly affected by drought treatments, and Posenati under SBF and NES treatments had greater yields than under ALS and SAF treatments, whereas Secle under SBF produced 80% more seeds than under NES. Total phenols, antioxidant capacity, and calcium content were significantly different among the local varieties. Yield was significantly and positively correlated with seed calcium content and significantly and negatively correlated with protein, total phenols, and antioxidant capacity. The interaction between local varieties and treatment significantly affected seeds’ Zn content. Gialet and Maron seeds’ Zn contents were about 60 mg kg−1, almost double the average of commercial varieties. In summary, this study paves the way to the identification of potential bean varieties resistant to drought. Further molecular studies will help support these findings.
Pietro Sica; Aline Galvao; Francesco Scariolo; Carmelo Maucieri; Carlo Nicoletto; Cristiane Pilon; Paolo Sambo; Gianni Barcaccia; Maurizio Borin; Miguel Cabrera; Dorcas Franklin. Effects of Drought on Yield and Nutraceutical Properties of Beans (Phaseolus spp.) Traditionally Cultivated in Veneto, Italy. Horticulturae 2021, 7, 17 .
AMA StylePietro Sica, Aline Galvao, Francesco Scariolo, Carmelo Maucieri, Carlo Nicoletto, Cristiane Pilon, Paolo Sambo, Gianni Barcaccia, Maurizio Borin, Miguel Cabrera, Dorcas Franklin. Effects of Drought on Yield and Nutraceutical Properties of Beans (Phaseolus spp.) Traditionally Cultivated in Veneto, Italy. Horticulturae. 2021; 7 (2):17.
Chicago/Turabian StylePietro Sica; Aline Galvao; Francesco Scariolo; Carmelo Maucieri; Carlo Nicoletto; Cristiane Pilon; Paolo Sambo; Gianni Barcaccia; Maurizio Borin; Miguel Cabrera; Dorcas Franklin. 2021. "Effects of Drought on Yield and Nutraceutical Properties of Beans (Phaseolus spp.) Traditionally Cultivated in Veneto, Italy." Horticulturae 7, no. 2: 17.
A study of phosphorus accumulation and mobility was conducted in eight pastures in the Georgia piedmont, USA. We compared two potential grazing treatments: strategic-grazing (STR) and continuous-grazing-with-hay-distribution (CHD) from 2015 (Baseline) to 2018 (Post-Treatment) for (1) distribution of Mehlich-1 Phosphorus (M1P) in soil and (2) dissolved reactive phosphorus (DRP) and total Kjeldahl phosphorus (TKP) in runoff water. STR included rotational grazing, excluding erosion vulnerable areas, and cattle-lure management using movable equipment (hay-rings, shades, and waterers). After three years of treatment, M1P had significantly accrued 6- and 5-fold in the 0–5 cm soil layer and by 2- and 1.6-fold in the 5–10 cm layer for CHD and STR, respectively, compared to Baseline M1P. In STR exclusions, M1P also increased to 10 cm depth post-treatment compared to Baseline. During Post-Treatment, TKP runoff concentrations were 21% and 29% lower, for CHD and STR, respectively, in 2018 compared to 2015. Hot Spot Analysis, a spatial clustering tool that utilizes Getis-Ord Gi* statistic, revealed no change in Post-Treatment CHD pastures, while hotspots in STR pastures had moved from low-lying to high-lying areas. Exclusion vegetation retained P and reduced bulk density facilitating vertical transportation of P deeper into the soil, ergo, soil P was less vulnerable to export in runoff, retained in the soil for forage utilization and reduced export of P to aquatic systems
Anish Subedi; Dorcas Franklin; Miguel Cabrera; Amanda McPherson; Subash Dahal. Grazing Systems to Retain and Redistribute Soil Phosphorus and to Reduce Phosphorus Losses in Runoff. Soil Systems 2020, 4, 66 .
AMA StyleAnish Subedi, Dorcas Franklin, Miguel Cabrera, Amanda McPherson, Subash Dahal. Grazing Systems to Retain and Redistribute Soil Phosphorus and to Reduce Phosphorus Losses in Runoff. Soil Systems. 2020; 4 (4):66.
Chicago/Turabian StyleAnish Subedi; Dorcas Franklin; Miguel Cabrera; Amanda McPherson; Subash Dahal. 2020. "Grazing Systems to Retain and Redistribute Soil Phosphorus and to Reduce Phosphorus Losses in Runoff." Soil Systems 4, no. 4: 66.
Generally, improvement in the soil health of pasturelands can result in amplified ecosystem services which can help improve the overall sustainability of the system. The extent to which specific best management practices have this effect has yet to be established. A farm-scale study was conducted in eight beef-pastures in the Southern Piedmont of Georgia, from 2015 to 2018, to assess the effect of strategic-grazing (STR) and continuous-grazing hay distribution (CHD) on soil health indicators and runoff nitrate losses. In 2016, four pastures were converted to the STR system and four were grazed using the CHD system. Post-treatment, in 2018, the STR system had significantly greater POXC (by 87.1, 63.4, and 55.6 mg ha−1 at 0–5, 5–10, and 10–20 cm, respectively) as compared to CHD system. Soil respiration was also greater in the STR system (by 235 mg CO2 m-2 24 h−1) and less nitrate was lost in the runoff (by 0.21 kg ha−1) as compared to the CHD system. Cattle exclusion and overseeding vulnerable areas of pastures in STR pastures facilitated nitrogen mineralization and uptake. Our results showed that the STR grazing system could improve the sustainability of grazing systems by storing more labile carbon, efficiently mineralizing soil nitrogen, and lowering runoff nitrate losses.
Subash Dahal; Dorcas Franklin; Anish Subedi; Miguel Cabrera; Dennis Hancock; Kishan Mahmud; Laura Ney; Cheolwoo Park; Deepak Mishra. Strategic Grazing in Beef-Pastures for Improved Soil Health and Reduced Runoff-Nitrate-A Step towards Sustainability. Sustainability 2020, 12, 558 .
AMA StyleSubash Dahal, Dorcas Franklin, Anish Subedi, Miguel Cabrera, Dennis Hancock, Kishan Mahmud, Laura Ney, Cheolwoo Park, Deepak Mishra. Strategic Grazing in Beef-Pastures for Improved Soil Health and Reduced Runoff-Nitrate-A Step towards Sustainability. Sustainability. 2020; 12 (2):558.
Chicago/Turabian StyleSubash Dahal; Dorcas Franklin; Anish Subedi; Miguel Cabrera; Dennis Hancock; Kishan Mahmud; Laura Ney; Cheolwoo Park; Deepak Mishra. 2020. "Strategic Grazing in Beef-Pastures for Improved Soil Health and Reduced Runoff-Nitrate-A Step towards Sustainability." Sustainability 12, no. 2: 558.
In order to ensure a soil system’s sustained ability to carry out ecosystem services, indicators that assess soil health are needed. We examined the capacity of nematode maturity index (MI), structure index (SI), enrichment index (EI), and trophic groups as measures of soil health, by determining soil nematodes’ sensitivity to cropping systems: rotation, perturbation, fertilization, and inoculation with local effective microorganisms (LEM). Plots were managed for two years under different rotations, annual ryegrass/fallow (ARF) and cereal rye/edamame soybean (CRS). In the third year of the study, all of the plots were managed exactly the same as a wheat/edamame rotation. Data were collected in both winter and summer of this year. In all three years, three inoculant treatments (LEM, False-LEM and No inoculate) were applied. In CRS plots, which received the most tillage and fertilization, there were greater SI values in soils that received LEM application. Nematode community structure described by each MI, SI, and EI were sensitive enough to reflect changes due to differences in soil management practices from previous years. Principal components analysis confirmed that nitrogen mineralization is an important measure to include when using nematode community analysis in the development of a soil health index.
Laura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Subash Dahal; Anish Subedi. Sensitivity of Nematode Community Analysis to Agricultural Management Practices and Inoculation with Local Effective Microorganisms in the Southeastern United States. Soil Systems 2019, 3, 41 .
AMA StyleLaura Ney, Dorcas Franklin, Kishan Mahmud, Miguel Cabrera, Dennis Hancock, Mussie Habteselassie, Quint Newcomer, Subash Dahal, Anish Subedi. Sensitivity of Nematode Community Analysis to Agricultural Management Practices and Inoculation with Local Effective Microorganisms in the Southeastern United States. Soil Systems. 2019; 3 (2):41.
Chicago/Turabian StyleLaura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Subash Dahal; Anish Subedi. 2019. "Sensitivity of Nematode Community Analysis to Agricultural Management Practices and Inoculation with Local Effective Microorganisms in the Southeastern United States." Soil Systems 3, no. 2: 41.
Cover crops can provide substantial quantities of N for subsequent crops, but estimating the amount of N that will be mineralized from residues is challenging. Complex interactions of residue chemistry with soil temperature and soil water content affect N mineralization during residue decomposition. A simulation model can describe these interactions and provide estimates of N mineralized if specific soil water and temperature data are available. Our objectives are (i) to describe a web-based N mineralization model and its operation, (ii) to calibrate the model with results from published N mineralization studies, and (iii) to validate it using field studies investigating decomposition of surface-applied or incorporated crimson clover (Trifolium incarnatum L.) or rye (Secale cereale L.) residues over 3 yr. Inputs required by the model include residue N, nonstructural carbohydrates, cellulose + hemi-cellulose, and lignin contents, as well as 5-yr average values of daily soil temperature and soil water content from a user-selected weather station. The model was successfully calibrated with published data from eight laboratory and field studies and was validated with data from field studies that used soil cores with cover crop residues. Simulated values of N mineralized were acceptable for incorporated residues but tended to overpredict N mineralized from surface residues because soil temperature and water content are not good drivers to simulate N mineralization from residues on the soil surface. Additional research is needed to develop algorithms to estimate temperature and water content/water potential of surface residues so they can be used as driver variables for the model. Copyright © 2018. . Copyright © by the Soil Science Society of America, Inc.
L.K. Woodruff; D.E. Kissel; M.L. Cabrera; M.Y. Habteselassie; R. Hitchcock; J. Gaskin; M. Vigil; L. Sonon; U. Saha; N. Romano; J. Rema. A Web-Based Model of N Mineralization from Cover Crop Residue Decomposition. Soil Science Society of America Journal 2018, 82, 983 -993.
AMA StyleL.K. Woodruff, D.E. Kissel, M.L. Cabrera, M.Y. Habteselassie, R. Hitchcock, J. Gaskin, M. Vigil, L. Sonon, U. Saha, N. Romano, J. Rema. A Web-Based Model of N Mineralization from Cover Crop Residue Decomposition. Soil Science Society of America Journal. 2018; 82 (4):983-993.
Chicago/Turabian StyleL.K. Woodruff; D.E. Kissel; M.L. Cabrera; M.Y. Habteselassie; R. Hitchcock; J. Gaskin; M. Vigil; L. Sonon; U. Saha; N. Romano; J. Rema. 2018. "A Web-Based Model of N Mineralization from Cover Crop Residue Decomposition." Soil Science Society of America Journal 82, no. 4: 983-993.
Broiler litter contains 17β-estradiol, estrone, and testosterone, which can contaminate surface waters when surface applied to grasslands and no-till fields. The objective of this study was to evaluate the effects of litter type (full or cake cleanout), litter treatment (none or sodium bisulfate), and number of flocks raised on the litter (1–5) on sex hormone concentrations. Our results showed that in untreated broiler litter, cake cleanout had greater concentrations of 17β-estradiol, estrone, and testosterone than full cleanout, whereas in litter treated with sodium bisulfate, only the concentration of 17β-estradiol was greater in cake than in full cleanout. The concentrations of 17β-estradiol and estrone in untreated broiler litter increased as the number of flocks increased from one to three, with the largest increase observed for estrone in cake cleanout. We also sampled three broiler houses in brooding and nonbrooding sections during the growout period. We found no differences in hormone concentrations between sections of each house, but changes in hormone concentrations during growout varied depending on broiler litter water content. Water contents corresponding to ∼60% water-filled porosity favored a decrease in hormone concentrations with time, whereas a water-filled porosity of 44% was associated with increases in hormone concentration, probably due to slow decomposition rates. Our results suggest that cake cleanout of untreated litter, as well as all cleanouts from houses that have raised several flocks on the same bedding, may be good targets for treatments that can reduce hormone concentrations before the litter is surface applied to fields. Copyright © 2018. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
M. L. Cabrera; D. E. Kissel; S. Hassan; J. A. Rema; K. Cassity-Duffey. Litter Type and Number of Flocks Affect Sex Hormones in Broiler Litter. Journal of Environmental Quality 2018, 47, 156 -161.
AMA StyleM. L. Cabrera, D. E. Kissel, S. Hassan, J. A. Rema, K. Cassity-Duffey. Litter Type and Number of Flocks Affect Sex Hormones in Broiler Litter. Journal of Environmental Quality. 2018; 47 (1):156-161.
Chicago/Turabian StyleM. L. Cabrera; D. E. Kissel; S. Hassan; J. A. Rema; K. Cassity-Duffey. 2018. "Litter Type and Number of Flocks Affect Sex Hormones in Broiler Litter." Journal of Environmental Quality 47, no. 1: 156-161.
The use of ionophores as antiparasitic drugs plays an important role in US poultry production, especially in the broiler () industry. However, administered ionophores can pass through the bird's digestive system and appear in broiler litter, which, when applied to agricultural fields, can present an environmental hazard. Stacking (storing or stockpiling) broiler litter for some time might decrease the litter ionophore concentrations before land application. Because ionophores undergo abiotic hydrolysis at low pH, decreasing litter pH with acidic aluminum sulfate (alum) might also decrease ionophore concentrations. We assessed the change in ionophore concentrations in broiler litter in response to the length of time broiler litter was stored (stacking time) and alum addition. We spiked broiler litter with monensin and salinomycin, placed alum-amended litter (∼pH 4-5) and unamended litter (∼pH 8-9) into 1.8-m bins, and repeatedly sampled each bin for 112 d. Our findings showed that stacking broiler litter alone did not have an impact on monensin concentration, but it did slowly reduce salinomycin concentration by 55%. Adding alum to broiler litter reduced monensin concentration by approximately 20% relative to unamended litter, but it did not change salinomycin concentration. These results call for continued search for alternative strategies that could potentially reduce the concentration of ionophores in broiler litter before their application to agricultural soils.
Sarah A. Doydora; Peizhe Sun; Miguel Cabrera; Aaron Thompson; Kimberly Love-Myers; John Rema; Vaughn Calvert; Spyros G. Pavlostathis; Ching-Hua Huang. Stacking Time and Aluminum Sulfate Effects on Polyether Ionophores in Broiler Litter. Journal of Environmental Quality 2015, 44, 1923 -1929.
AMA StyleSarah A. Doydora, Peizhe Sun, Miguel Cabrera, Aaron Thompson, Kimberly Love-Myers, John Rema, Vaughn Calvert, Spyros G. Pavlostathis, Ching-Hua Huang. Stacking Time and Aluminum Sulfate Effects on Polyether Ionophores in Broiler Litter. Journal of Environmental Quality. 2015; 44 (6):1923-1929.
Chicago/Turabian StyleSarah A. Doydora; Peizhe Sun; Miguel Cabrera; Aaron Thompson; Kimberly Love-Myers; John Rema; Vaughn Calvert; Spyros G. Pavlostathis; Ching-Hua Huang. 2015. "Stacking Time and Aluminum Sulfate Effects on Polyether Ionophores in Broiler Litter." Journal of Environmental Quality 44, no. 6: 1923-1929.
M.L. Cabrera; D.E. Kissel; M.F. Vigil. Potential Nitrogen Mineralization: Laboratory and Field Evaluation. SSSA Special Publications 2015, 15 -30.
AMA StyleM.L. Cabrera, D.E. Kissel, M.F. Vigil. Potential Nitrogen Mineralization: Laboratory and Field Evaluation. SSSA Special Publications. 2015; ():15-30.
Chicago/Turabian StyleM.L. Cabrera; D.E. Kissel; M.F. Vigil. 2015. "Potential Nitrogen Mineralization: Laboratory and Field Evaluation." SSSA Special Publications , no. : 15-30.
In most terrestrial ecosystems, nitrogen (N) is the most limiting nutrient for plant growth. Honey bees may help alleviate this limitation because their feces (frass) have high concentration of organic nitrogen that may decompose in soil and provide inorganic N to plants. However, information on soil N processes associated with bee frass is not available. The objectives of this work were to 1) estimate the amount of bee frass produced by a honey bee colony and 2) evaluate nitrogen mineralization and ammonia volatilization from bee frass when surface applied or incorporated into soil. Two cage studies were conducted to estimate the amount of frass produced by a 5000-bee colony, and three laboratory studies were carried out in which bee frass, surface-applied or incorporated into soil, was incubated at 25oC for 15 to 45 days. The average rate of bee frass production by a 5,000-bee colony was estimated at 2.27 to 2.69 g N month−1. Nitrogen mineralization from bee frass during 30 days released 20% of the organic N when bee frass was surface applied and 34% when frass was incorporated into the soil. Volatilized NH3 corresponded to 1% or less of total N. The potential amount of inorganic N released to the soil by a typical colony of 20,000 bees foraging in an area similar to that of the experimental cages (3.24 m2) was estimated at 0.62 to 0.74 g N m−2 month−1 which may be significant at a community scale in terms of soil microbial activity and plant growth. Thus, the deposition of available N by foraging bees could have adaptive benefits for the plants they visit, a collateral benefit deriving from the primary activity of pollination.
Archana Mishra; Ohad Afik; Miguel L. Cabrera; Keith S. Delaplane; Jason E. Mowrer. Inorganic Nitrogen Derived from Foraging Honey Bees Could Have Adaptive Benefits for the Plants They Visit. PLOS ONE 2013, 8, e70591 .
AMA StyleArchana Mishra, Ohad Afik, Miguel L. Cabrera, Keith S. Delaplane, Jason E. Mowrer. Inorganic Nitrogen Derived from Foraging Honey Bees Could Have Adaptive Benefits for the Plants They Visit. PLOS ONE. 2013; 8 (7):e70591.
Chicago/Turabian StyleArchana Mishra; Ohad Afik; Miguel L. Cabrera; Keith S. Delaplane; Jason E. Mowrer. 2013. "Inorganic Nitrogen Derived from Foraging Honey Bees Could Have Adaptive Benefits for the Plants They Visit." PLOS ONE 8, no. 7: e70591.
Biochar can potentially increase soil fertility and sequester carbon by incorporating nutrients and stable black carbon into the soil; however its effect on soil nitrogen (N) and carbon (C) processes is not well understood. A defined methodology to characterize biochar is necessary to predict how specific biochars will affect C and N mineralization. We amended a Tifton soil (Fine-loamy, siliceous, thermic Plinthic Kandiudults) with peanut hull (Arachis hypogaea; PH; 2.1% N) and pine chip (Pinus taeda; PC: 0.4% N) biochar at application rates of 1% and 2% (w/w) and performed a 136-day mineralization study. A companion 24-day mineralization study amended Tifton soil with PH and PC biochar at 2% and their respective feedstocks at equal C rates. Soil C mineralization rates were monitored periodically throughout each study and total N mineralization rates were also measured. In addition, we characterized each biochar using thermogravimetric analysis with mass spectrometer (TGA-MS), proximate analysis, Fourier transform infrared spectroscopy (FTIR), and total mineral analysis to identify biochar characteristics that might correlate with mineralization properties. Limited C (<2%) mineralized from both biochars, but mineralization rates of soil amended with PH biochar were higher than PC biochar. Carbon mineralization correlated well with estimated aliphatic content determined by TGA-MS but not with volatile content indicated by proximate analysis. Nitrogen was not mineralized from either biochar, indicating that plant-based biochar should not be considered a source of N for plant growth. The N in biochar may be contained in the stable aromatic structure of the biochar, as indicated by TGA-MS, and not available to soil microbes.
Keith Harris; Julia Gaskin; Miguel Cabrera; William Miller; K.C. Das. Characterization and Mineralization Rates of Low Temperature Peanut Hull and Pine Chip Biochars. Agronomy 2013, 3, 294 -312.
AMA StyleKeith Harris, Julia Gaskin, Miguel Cabrera, William Miller, K.C. Das. Characterization and Mineralization Rates of Low Temperature Peanut Hull and Pine Chip Biochars. Agronomy. 2013; 3 (2):294-312.
Chicago/Turabian StyleKeith Harris; Julia Gaskin; Miguel Cabrera; William Miller; K.C. Das. 2013. "Characterization and Mineralization Rates of Low Temperature Peanut Hull and Pine Chip Biochars." Agronomy 3, no. 2: 294-312.
17β-estradiol and testosterone are naturally occurring steroids that co-occur in poultry litter. The effects of litter on sorption of these hormones to soil are not known. Sorption isotherms were developed for 14C-labeled testosterone and 3H-labeled estradiol in a Cecil sandy clay loam with and without poultry litter addition. The effect of applying the hormones alone (single-sorbate) or together (multisorbate) was also investigated. 14C-testosterone sorption in soil increased from 2 to 48 h and remained relatively constant thereafter. 3H-estradiol sorption in soil was relatively constant from 2 to 24 h and then decreased to 72 h. These differences may reflect transformation of the parent hormones to products with different solid-phase affinity. The maximum sorption coefficient (Kd) in soil for 14C-testosterone (20.2 mL g−1) was similar to that for 3H-estradiol (19.6 mL g−1) in single-sorbate experiments. When hormones were applied together, sorption of both hormones in soil decreased, but the 14C-testosterone Kd (12.5 mL g−1) was nearly twice as large as the 3H-estradiol Kd (7.4 mL g−1). We propose this resulted from competition between the hormones and their transformation products for sorption sites, with 14C-testosterone and its expected transformation product (androstenedione) being better competitors than 3H-estradiol and its expected transformation product (estrone). When poultry litter was mixed with soil, sorption increased for 3H-estradiol but decreased for 14C-testosterone. This may have been because poultry litter slowed the transformation of parent hormones. Our results show that poultry litter could have important effects on the mobility of estradiol and testosterone. Copyright © 2011. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
M. Bera; D. E. Radcliffe; M. L. Cabrera; W. K. Vencill; A. Thompson; Sayed Hassan. 17β-Estradiol and Testosterone Sorption in Soil with and without Poultry Litter. Journal of Environmental Quality 2011, 40, 1983 -1990.
AMA StyleM. Bera, D. E. Radcliffe, M. L. Cabrera, W. K. Vencill, A. Thompson, Sayed Hassan. 17β-Estradiol and Testosterone Sorption in Soil with and without Poultry Litter. Journal of Environmental Quality. 2011; 40 (6):1983-1990.
Chicago/Turabian StyleM. Bera; D. E. Radcliffe; M. L. Cabrera; W. K. Vencill; A. Thompson; Sayed Hassan. 2011. "17β-Estradiol and Testosterone Sorption in Soil with and without Poultry Litter." Journal of Environmental Quality 40, no. 6: 1983-1990.
A. Mishra; M. L. Cabrera; J. A. Rema. Phosphorus fractions in poultry litter as affected by flue-gas desulphurization gypsum and litter stacking. Soil Use and Management 2011, 28, 27 -34.
AMA StyleA. Mishra, M. L. Cabrera, J. A. Rema. Phosphorus fractions in poultry litter as affected by flue-gas desulphurization gypsum and litter stacking. Soil Use and Management. 2011; 28 (1):27-34.
Chicago/Turabian StyleA. Mishra; M. L. Cabrera; J. A. Rema. 2011. "Phosphorus fractions in poultry litter as affected by flue-gas desulphurization gypsum and litter stacking." Soil Use and Management 28, no. 1: 27-34.
In regions of concentrated poultry production, poultry litter (PL) that contains significant quantities of trace elements is commonly surface-applied to pastures at high levels over multiple years. This study examined the effect of long-term applications of PL on soil concentrations of arsenic (As), copper (Cu), Zinc (Zn), and the uptake of these elements by bermuda grass grown on Cecil (well-drained) and Sedgefield (somewhat poorly-drained) soils. The results showed that concentrations of As, Cu, and Zn in soils that had received surface-applied PL over a 14-year period were significantly greater than untreated soil at 0–2.5 and 2.5–7.5 cm depths. However, the levels were well below the USEPA loading limits established for municipal biosolids. Arsenic fractionation showed that concentrations of all As fractions were significantly greater in PL-amended soils compared to untreated soils at 0–2.5 and 2.5–7.5 cm depths. The residual fraction was the predominant form of As in all soils. The water-soluble and NaHCO3-associated As were only 2% of the total As. Significant differences were found in concentrations of these trace elements and phosphorus (P) in forage from PL-amended soils compared to that in untreated plots. The concentrations of Cu, Zn, As, and P were significantly greater in forage from Sedgefield amended soil compared to Cecil soil, but were in all cases below levels of environmental concern.
Shadi Ashjaei; William P. Miller; Miguel L. Cabrera; Sayed M. Hassan. Arsenic in Soils and Forages from Poultry Litter-Amended Pastures. International Journal of Environmental Research and Public Health 2011, 8, 1534 -1546.
AMA StyleShadi Ashjaei, William P. Miller, Miguel L. Cabrera, Sayed M. Hassan. Arsenic in Soils and Forages from Poultry Litter-Amended Pastures. International Journal of Environmental Research and Public Health. 2011; 8 (5):1534-1546.
Chicago/Turabian StyleShadi Ashjaei; William P. Miller; Miguel L. Cabrera; Sayed M. Hassan. 2011. "Arsenic in Soils and Forages from Poultry Litter-Amended Pastures." International Journal of Environmental Research and Public Health 8, no. 5: 1534-1546.
Application of poultry litter (PL) to soil may lead to nitrogen (N) losses through ammonia (NH3) volatilization and to potential contamination of surface runoff with PL-derived phosphorus (P). Amending litter with acidified biochar may minimize these problems by decreasing litter pH and by retaining litter-derived P, respectively. This study evaluated the effect of acidified biochars from pine chips (PC) and peanut hulls (PH) on NH3 losses and inorganic N and P released from surface-applied or incorporated PL. Poultry litter with or without acidified biochars was surface-applied or incorporated into the soil and incubated for 21 d. Volatilized NH3 was determined by trapping it in acid. Inorganic N and P were determined by leaching the soil with 0.01 M of CaCl2 during the study and by extracting it with 1 M KCl after incubation. Acidified biochars reduced NH3 losses by 58 to 63% with surface-applied PL, and by 56 to 60% with incorporated PL. Except for PH biochar, which caused a small increase in leached NH4+-N with incorporated PL, acidified biochars had no effect on leached or KCl-extractable inorganic N and P from surface-applied or incorporated PL. These results suggest that acidified biochars may decrease NH3 losses from PL but may not reduce the potential for P loss in surface runoff from soils receiving PL.
Sarah A. Doydora; Miguel L. Cabrera; Keshav C. Das; Julia W. Gaskin; Leticia S. Sonon; William P. Miller. Release of Nitrogen and Phosphorus from Poultry Litter Amended with Acidified Biochar. International Journal of Environmental Research and Public Health 2011, 8, 1491 -1502.
AMA StyleSarah A. Doydora, Miguel L. Cabrera, Keshav C. Das, Julia W. Gaskin, Leticia S. Sonon, William P. Miller. Release of Nitrogen and Phosphorus from Poultry Litter Amended with Acidified Biochar. International Journal of Environmental Research and Public Health. 2011; 8 (5):1491-1502.
Chicago/Turabian StyleSarah A. Doydora; Miguel L. Cabrera; Keshav C. Das; Julia W. Gaskin; Leticia S. Sonon; William P. Miller. 2011. "Release of Nitrogen and Phosphorus from Poultry Litter Amended with Acidified Biochar." International Journal of Environmental Research and Public Health 8, no. 5: 1491-1502.
Some micrometeorological methods for measuring NH3 loss use passive flux samplers with oxalic acid coated glass tubes. In previous work, we observed that tubes that had been exposed in plots with broiler litter, cleaned with 0.32 mol L−1 HCl and recoated, had uneven oxalic acid coating, which may lead to NH3 bypass. One of the objectives of this study was to measure the NH3–trapping capacity of previously exposed tubes that were cleaned by either washing and scrubbing with 0.32 mol L−1 HCl or heating at 560°C for 1 h before being recoated with oxalic acid. There were no detectable differences between cleaning methods in adsorbed NH3, but tubes cleaned with 0.32 mol L−1 HCl had uneven oxalic acid coating that led to a 7.3% NH3 bypass. Tubes cleaned by heating at 560°C for 1 h had even coating and no NH3 bypass. Presumably, heating the tubes at 560°C oxidized volatile organic compounds bound to the glass, which were acting as nucleating points for oxalic acid. A second objective of this study was to compare a passive flux method with masts on the periphery of a circular plot (PM method) to a method with a central, rotating mast at the center of the plot (CM method). Results from three field studies on tall fescue (Festuca arundinacea Shreb.) pastures showed that the PM method underestimated NH3 losses by 31 to 37% compared with the CM method. These underestimations were probably caused by NH3 bypass from tubes exposed to background NH3. Our results suggest that the CM method may be preferable to the PM method when environmental conditions favor NH3 bypass. Copyright © 2011. . Copyright © by the Soil Science Society of America, Inc.
M. L. Cabrera; N. Vaio; J. Rema; L. Braun; D. E. Kissel. Comparison of Two Passive Flux Methods to Measure Ammonia Volatilization. Soil Science Society of America Journal 2011, 75, 949 -956.
AMA StyleM. L. Cabrera, N. Vaio, J. Rema, L. Braun, D. E. Kissel. Comparison of Two Passive Flux Methods to Measure Ammonia Volatilization. Soil Science Society of America Journal. 2011; 75 (3):949-956.
Chicago/Turabian StyleM. L. Cabrera; N. Vaio; J. Rema; L. Braun; D. E. Kissel. 2011. "Comparison of Two Passive Flux Methods to Measure Ammonia Volatilization." Soil Science Society of America Journal 75, no. 3: 949-956.
In the United States, approximately 600,000 ha of pine trees are fertilized with urea each year, with NH3 volatilization losses ranging from 50% depending on environmental conditions. Previous work showed that the timing of rainfall after urea application plays a significant role in controlling NH3 loss, but the effect of other environmental variables is not well understood. We conducted 10 29-d studies under different environmental conditions during 2 yr to identify important variables controlling NH3 loss from urea applied to loblolly pine (Pinus taeda L.) at 200 kg N ha−1 Ammonia loss was measured with dynamic chambers that adjusted the rate of air flow through the system based on wind speed at 1 cm above the soil surface. Regression analysis indicated that a variable related to the initial water content of the forest floor and a variable related to the relative humidity (RH) during the study explained 85 to 94% of the observed variability in NH3 loss. Relatively high initial water content followed by consistently high RH led to large NH3 losses. In contrast, low initial water contents resulted in slow rates of NH3 loss, which increased when elevated RH led to an increase in the water content of the forest floor. These results indicate that RH can play a significant role in NH3 loss by accelerating urea dissolution and by increasing or decreasing the water content of the forest floor, which in turn can affect the rate of urea hydrolysis. Copyright © 2010. Soil Science Society. Soil Science Society of America
M. L. Cabrera; D. E. Kissel; J. R. Craig; Nikolla P. Qafoku; N. Vaio; J. A. Rema; L. A. Morris. Relative Humidity Controls Ammonia Loss from Urea Applied to Loblolly Pine. Soil Science Society of America Journal 2010, 74, 543 -549.
AMA StyleM. L. Cabrera, D. E. Kissel, J. R. Craig, Nikolla P. Qafoku, N. Vaio, J. A. Rema, L. A. Morris. Relative Humidity Controls Ammonia Loss from Urea Applied to Loblolly Pine. Soil Science Society of America Journal. 2010; 74 (2):543-549.
Chicago/Turabian StyleM. L. Cabrera; D. E. Kissel; J. R. Craig; Nikolla P. Qafoku; N. Vaio; J. A. Rema; L. A. Morris. 2010. "Relative Humidity Controls Ammonia Loss from Urea Applied to Loblolly Pine." Soil Science Society of America Journal 74, no. 2: 543-549.
The use of urea fertilizers in grasslands is likely to increase in areas with concentrated animal feeding operations as restrictions on manure applications are implemented. Concerns have been raised about the economic and environmental impacts of NH3 loss from these urea fertilizers. This study evaluated NH3 losses from Nitamin (a urea polymer), urea–NH4NO3 (UAN), and granular urea applied to tall fescue (Festuca arundinacea Schreb.) plots at 50 kg N ha−1 in fall and spring for 2 yr. Fertilizers were applied to circular plots (30-m diameter) and NH3 loss was measured by the modified passive flux method for 69 to 120 d after application. In a separate laboratory study, Nitamin, UAN, and urea were surfaced applied to fescue thatch at 100 kg N ha−1 and treatments were incubated at 24°C and 90% relative humidity for 31 d. In fall applications, urea lost more NH3 (19% in 2004, 46% in 2005) than UAN or Nitamin, which were not different from each other (6% in 2004, 34% in 2005). In contrast, there were no differences among fertilizers in spring applications, with average losses of 13% in 2005 and 17% in 2006. In the laboratory study, urea lost significantly more NH3 (24%) than UAN or Nitamin, which were not different from each other (average 9% loss). These results indicate that Nitamin and UAN undergo similar NH3 losses, and that both fertilizers may lose less NH3 than urea under conditions favorable to volatilization. Copyright © 2008. Soil Science Society. Soil Science Society of America
Nicolas Vaio; Miguel L. Cabrera; D.E. Kissel; John A. Rema; J. Frank Newsome; Vaughn H. Calvert. Ammonia Volatilization from Urea-Based Fertilizers Applied to Tall Fescue Pastures in Georgia, USA. Soil Science Society of America Journal 2008, 72, 1665 -1671.
AMA StyleNicolas Vaio, Miguel L. Cabrera, D.E. Kissel, John A. Rema, J. Frank Newsome, Vaughn H. Calvert. Ammonia Volatilization from Urea-Based Fertilizers Applied to Tall Fescue Pastures in Georgia, USA. Soil Science Society of America Journal. 2008; 72 (6):1665-1671.
Chicago/Turabian StyleNicolas Vaio; Miguel L. Cabrera; D.E. Kissel; John A. Rema; J. Frank Newsome; Vaughn H. Calvert. 2008. "Ammonia Volatilization from Urea-Based Fertilizers Applied to Tall Fescue Pastures in Georgia, USA." Soil Science Society of America Journal 72, no. 6: 1665-1671.
Incubation of soil with CaCO3 is generally considered a reliable method to determine the lime requirement (LR) of acid soils. Because of their considered reliability, these incubations are often used to calibrate buffer methods; however, one study reported that the use of room temperature incubation with CaCO3 overestimated the actual LR determined by field testing. The objective of this study was to compare the pH change following CaCO3 incubations for 60 d with those following 3-d incubations with Ca(OH)2 and to determine the possible role of soil N reactions causing any differences in pH change. Seventeen soils were incubated with either CaCO3 for 60 d at approximately 85% field capacity or for 3 d with an equivalent amount of Ca(OH)2 solution plus water to maintain a 1:1 soil/solution ratio. Both were incubated at room temperature (23 ± 2°C), followed by measurement of pH (1:1 in water). Ammonium-N and NO3−–N were analyzed at Days 0 and 60 of the incubation. Soil pH was lower following the 60-d CaCO3 incubation than after the 3-d incubation with Ca(OH)2 The analysis of N transformations indicated that positive values of H+ (more H+ was produced than consumed) were generated from nitrification after 60 d of incubation in 14 out of 17 soils. Furthermore, incubations with soils that have been air dried produced a flush of nitrification that increased the ionic strength and decreased pH even further. These effects from long-term incubation would erroneously increase the LR. Incubation with Ca(OH)2 for 2 to 4 d avoids these errors. Copyright © 2008. Soil Science Society. Soil Science Society of America
Min Liu; D. E. Kissel; L. S. Sonon; M. L. Cabrera; P. F. Vendrell. Effects of Biological Nitrogen Reactions on Soil Lime Requirement Determined by Incubation. Soil Science Society of America Journal 2008, 72, 720 -726.
AMA StyleMin Liu, D. E. Kissel, L. S. Sonon, M. L. Cabrera, P. F. Vendrell. Effects of Biological Nitrogen Reactions on Soil Lime Requirement Determined by Incubation. Soil Science Society of America Journal. 2008; 72 (3):720-726.
Chicago/Turabian StyleMin Liu; D. E. Kissel; L. S. Sonon; M. L. Cabrera; P. F. Vendrell. 2008. "Effects of Biological Nitrogen Reactions on Soil Lime Requirement Determined by Incubation." Soil Science Society of America Journal 72, no. 3: 720-726.
Aeration has been promoted as improving infiltration of rainfall and extending grass or forage productivity, but research on the impact of this practice on P losses from grasslands has had mixed results. We designed a study to determine at the field scale, using a paired watershed approach, the impact of slit aeration on runoff volume and P losses in runoff from fescue (Festuca arundinacea Schreb.)/bermudagrass (Cynodon dactylon L.) hay fields fertilized with broiler litter. Three pairs of 0.8-ha fields, each with similar soils (Typic Kanhapludults, Aquic Hapludults, and Aquultic Hapludalfs), were fertilized with broiler litter and monitored under similar management from 1995 through 1998, then one field in each pair received aeration treatment from 2001 through 2003. In the field with mostly well-drained soils, grassland aeration reduced surface runoff volume and mass losses of dissolved reactive P (DRP) in runoff by approximately 35%. In contrast, when poorly drained soils dominated, grassland aeration increased runoff volume (4.8 mm/runoff event) and mass losses of DRP and total P (0.25 kg TP ha−1 per runoff event). This implies that aeration of well-drained soils in the top poultry-producing counties of Georgia (0.2 million ha) could decrease dissolved phosphorus losses by more than 500 Mg P each year. This is not the case if soils are poorly drained. Copyright © 2007. American Society of Agronomy, Crop Science Society of America, Soil Science Society. ASA, CSSA, SSSA
D. H. Franklin; M. L. Cabrera; L. T. West; V. H. Calvert; J. A. Rema. Aerating Grasslands. Journal of Environmental Quality 2007, 36, 208 -215.
AMA StyleD. H. Franklin, M. L. Cabrera, L. T. West, V. H. Calvert, J. A. Rema. Aerating Grasslands. Journal of Environmental Quality. 2007; 36 (1):208-215.
Chicago/Turabian StyleD. H. Franklin; M. L. Cabrera; L. T. West; V. H. Calvert; J. A. Rema. 2007. "Aerating Grasslands." Journal of Environmental Quality 36, no. 1: 208-215.