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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.
Soil microbial communities are key players in the development of sustainable food production systems. These soil microbes are responsible for macronutrient and micronutrient mineralization and solubilization in soil. Local effective microorganisms (LEM) are a locally sourced bio-inoculate, made from a fermented mixture of actively decomposing forest litter and a nutrient rich growing media containing carbohydrate, milk, and water. It can be made on farm and have a suite of bacterial communities that includes phototrophic bacteria, phosphorous-solubilizers, ammonia-oxidizers, nitrogen fixers, and actinomycetes. The goal of our research was to (a) investigate microbial diversity in LEM and F-LEM bio-inocula; (b) identify bacterial and archaeal communities in soil after bio-inoculation with LEM, F-LEM, or Control; (c) assess inorganic nitrogen in the soil; and (d) evaluate Ca, Mg, K, and Zn nutrient density in edamame bean (Glycine max) grown with composted broiler litter inoculated with LEM, F-LEM, or Water (Control). Treatments were arranged in a completely randomized block design with four replications on twelve, 18 m2 organically managed plots. Results of microbial characterization indicated greater biodiversity of functional groups in the LEM inoculum. Inorganic N was significantly greater in LEM plots compared to Control in second (2016) and third (2017) years of the study. Biofortification of calcium, magnesium, and zinc density of LEM grown edamame was significantly greater compared to both Control and False-LEM grown edamame (*P < 0.05).
Kishan Mahmud; Dorcas Franklin; Laura Ney; Miguel Cabrera; Mussie Habteselassie; Dennis Hancock; Quint Newcomer; Anish Subedi; Subash Dahal. Improving inorganic nitrogen in soil and nutrient density of edamame bean in three consecutive summers by utilizing a locally sourced bio-inocula. Organic Agriculture 2021, 11, 133 -143.
AMA StyleKishan Mahmud, Dorcas Franklin, Laura Ney, Miguel Cabrera, Mussie Habteselassie, Dennis Hancock, Quint Newcomer, Anish Subedi, Subash Dahal. Improving inorganic nitrogen in soil and nutrient density of edamame bean in three consecutive summers by utilizing a locally sourced bio-inocula. Organic Agriculture. 2021; 11 (1):133-143.
Chicago/Turabian StyleKishan Mahmud; Dorcas Franklin; Laura Ney; Miguel Cabrera; Mussie Habteselassie; Dennis Hancock; Quint Newcomer; Anish Subedi; Subash Dahal. 2021. "Improving inorganic nitrogen in soil and nutrient density of edamame bean in three consecutive summers by utilizing a locally sourced bio-inocula." Organic Agriculture 11, no. 1: 133-143.
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.
Local effective microorganism (LEM) is an inoculant produced using leaf litter collected from forest floors near the location where it is to be utilized. While this locally-sourced inoculant is used around the world, more research is needed to fully understand the potential benefits or drawbacks of its use in agricultural systems. The objectives of this study were to observe the effects of combining LEM with composted broiler litter to fertilize edamame (Glycine max L.) on plant-available nitrogen, nematode trophic group communities, and soybean productivity. The study was carried out in a randomized, complete block design on piedmont soils in the southeastern United States comparing broiler litter composted with LEM, False-LEM or water (Control) treatments which were applied at the beginning of each growing season (June 2015, 2016, 2017). In the first year of the study, soil (0–10 cm) that received the LEM treatment mineralized greater amounts of N and mineralized N faster than CONT soils (P = 0.0665 and P = 0.0717), respectively, during one week of incubation. In year 2 (2016) plots experienced drought stress, with soil moistures as low as 2%. In LEM plots soil samples taken during the drought contained significantly greater populations of all nematodes, excluding Mononchidae when compared to the other treatments. When calculated per unit of soil N, measured after application of treatments, no differences in edamame soybean yield were observed between treatments. Combining LEM with composted broiler litter jump-started N mineralization early in growing seasons and maintained abundance of multiple nematode trophic groups during drought. This signifies LEM's potential to strengthen a soil's food web resistance to drought stress – providing more security for a functional agroecosystem under uncertain climate conditions.
Laura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Subash Dahal. Impact of inoculation with local effective microorganisms on soil nitrogen cycling and legume productivity using composted broiler litter. Applied Soil Ecology 2020, 154, 103567 .
AMA StyleLaura Ney, Dorcas Franklin, Kishan Mahmud, Miguel Cabrera, Dennis Hancock, Mussie Habteselassie, Quint Newcomer, Subash Dahal. Impact of inoculation with local effective microorganisms on soil nitrogen cycling and legume productivity using composted broiler litter. Applied Soil Ecology. 2020; 154 ():103567.
Chicago/Turabian StyleLaura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Subash Dahal. 2020. "Impact of inoculation with local effective microorganisms on soil nitrogen cycling and legume productivity using composted broiler litter." Applied Soil Ecology 154, no. : 103567.
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.
Disinfecting soil can reduce or eliminate crop loss from soilborne pathogens, parasitic nematodes, and weed competition. Biosolarization combines biotoxic products from organic matter decomposition and heat from solarization. While biosolarization offers an organic option for soil pest control and avoids human and environmental health risks associated with chemical fumigants, it still has broad negative impacts on microbial communities. Quickly reestablishing these communities can be key in preventing resurgence in disease pressure and in maximizing nutrient use efficiency. The objective of this study was to determine the ability of fertilization source, N fertilization rate, and/or inoculate to rebuild an active soil ecosystem in biosolarized soils by measuring nematode community structure, microbial biomass, and C and N mineralization in soil as well as kale yield and quality. The study was conducted using potted kale grown in biosolarized soils. Treatments were bare soil, receiving no fertilization, and soils receiving two different rates of organic, composted broiler litter or mineral fertilizer. Half of the pots in each treatment received a locally sourced microbial inoculant (LEM). Among the nonfertilized treatments, the soils that received applications of LEM mineralized more nitrogen and produced higher yields. Soils that received the highest rate of compost immobilized the greatest proportion of nitrogen applied, were the most cold-tolerant, and produced the largest yields. None of the kale that received heavy mineral fertilization without LEM inoculation survived a hard freeze; however, the ones that received LEM applications were able to partially recover. We also found that kale grown with lower rates of N (50 kg·ha−1), applied as compost plus LEM, had the greatest magnesium leaf content and were more economically efficient while producing an equally abundant and nutritious food.
Laura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Brendan Fatzinger. Rebuilding Soil Ecosystems for Improved Productivity in Biosolarized Soils. International Journal of Agronomy 2019, 2019, 1 -10.
AMA StyleLaura Ney, Dorcas Franklin, Kishan Mahmud, Miguel Cabrera, Dennis Hancock, Mussie Habteselassie, Quint Newcomer, Brendan Fatzinger. Rebuilding Soil Ecosystems for Improved Productivity in Biosolarized Soils. International Journal of Agronomy. 2019; 2019 ():1-10.
Chicago/Turabian StyleLaura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer; Brendan Fatzinger. 2019. "Rebuilding Soil Ecosystems for Improved Productivity in Biosolarized Soils." International Journal of Agronomy 2019, no. : 1-10.
Sufficient and consistent distribution of carbon (C) across pastures can influence and improve production and sustainability in pasture-based grazing systems. The objective of this research was to determine spatial distribution of bulk density, soil C measured as loss-on-ignition (LOI) C, and permanganate oxidizable C (POXC), in continuously stocked Southern Piedmont pastures as affected by landscape position and management to enable producers to make better informed management decisions. Soil samples were collected from three depths (0 to 5, 5 to 10, and 10 to 20 cm), on a 50 m grid (matrix) and within areas of interest (AOIs, where cattle tended to frequent) from 10 pastures (ranging from 9.2 to 21.8 ha) fertilized with only mineral fertilizer. Mean soil bulk density was greatest (μ = 1.62 g cm−3) in the 5 to 10 cm soil layer. Median soil LOI and POXC were greatest in the 0 to 5 cm soil layer (medians = 6.16 g kg−1 and 776 mg kg−1, respectively), and both were strongly correlated to soil organic C. Soil phosphorus (P) was lowest in the 10 to 20 cm samples (median = 2.12 mg kg−1), regardless of sampling location. Multivariate analysis of variance (MANOVA) determined that bulk densities were lower closer to hay and water sources (usually within 0 to 39 m from sources) not located in areas vulnerable to erosion likely because of added C combined with the moderate hoof action to incorporate C into the soil. However, LOI values in the surface 0 to 5 cm soil layer associated with hay, water, and shade in areas vulnerable to erosion demonstrated relatively few differences in distance from a hay, water, or shade source, and these differences often did not occur until 200 m or greater from a pasture equipage. This research indicates that producers can more efficiently utilize nutrient resources and improve soil health measures with strategic placement of hay, waterers, or shade to facilitate best use of limited resources.
T. Hendricks; Dorcas Franklin; Subash Dahal; D. Hancock; L. Stewart; M. Cabrera; G. Hawkins. Soil carbon and bulk density distribution within 10 Southern Piedmont grazing systems. Journal of Soil and Water Conservation 2019, 74, 323 -333.
AMA StyleT. Hendricks, Dorcas Franklin, Subash Dahal, D. Hancock, L. Stewart, M. Cabrera, G. Hawkins. Soil carbon and bulk density distribution within 10 Southern Piedmont grazing systems. Journal of Soil and Water Conservation. 2019; 74 (4):323-333.
Chicago/Turabian StyleT. Hendricks; Dorcas Franklin; Subash Dahal; D. Hancock; L. Stewart; M. Cabrera; G. Hawkins. 2019. "Soil carbon and bulk density distribution within 10 Southern Piedmont grazing systems." Journal of Soil and Water Conservation 74, no. 4: 323-333.
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.
Uneven spatial distribution of soil N in conventionally managed pastures is a function of various biotic and abiotic factors and results in poor land use efficiency. In this study, we measured soil inorganic N (at depths of 0–5, 5–10, and 10–20 cm) in a 50-m grid and specific areas of interest from eight conventionally managed beef pastures (∼17 ha each), four near Eatonton and four near Watkinsville in the southern Piedmont of Georgia, USA, to assess the effects of management, landscape, and cattle locus in spatial distribution of soil inorganic N. Significant spatial autocorrelation was observed in the soil inorganic N indicating that the regions of high inorganic N deposition were near (within 91 m of) one or more pasture equipage (hay, shade, and water). In the Watkinsville pastures, inorganic N was 65% higher within 5 m of shade than the rest of the pastures, down to a 10-cm soil depth. In the Eatonton pastures, inorganic N (0–5 cm) was 22% higher within 30 m of a hay-feeding areas than the rest of the pasture. Cattle locus calculated as cattle density (cow ha−1 yr−1) was a function of pasture equipage and had a significant positive relationship with soil inorganic N. Landscape parameters (slope and elevation) significantly affected inorganic N distribution; however, the effect was small and was masked by management factors. Our results suggest that strategic placement of pasture equipage (hay, shade, and water) can effectively distribute N where needed in beef pastures, thereby increasing land use efficiency. Copyright © 2018. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Subash Dahal; Dorcas H. Franklin; Miguel L. Cabrera; Dennis W. Hancock; Lawton Stewart; Laura C. Ney; Anish Subedi; Kishan Mahmud. Spatial Distribution of Inorganic Nitrogen in Pastures as Affected by Management, Landscape, and Cattle Locus. Journal of Environmental Quality 2018, 47, 1468 -1477.
AMA StyleSubash Dahal, Dorcas H. Franklin, Miguel L. Cabrera, Dennis W. Hancock, Lawton Stewart, Laura C. Ney, Anish Subedi, Kishan Mahmud. Spatial Distribution of Inorganic Nitrogen in Pastures as Affected by Management, Landscape, and Cattle Locus. Journal of Environmental Quality. 2018; 47 (6):1468-1477.
Chicago/Turabian StyleSubash Dahal; Dorcas H. Franklin; Miguel L. Cabrera; Dennis W. Hancock; Lawton Stewart; Laura C. Ney; Anish Subedi; Kishan Mahmud. 2018. "Spatial Distribution of Inorganic Nitrogen in Pastures as Affected by Management, Landscape, and Cattle Locus." Journal of Environmental Quality 47, no. 6: 1468-1477.
Laura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer. Examining trophic-level nematode community structure and nitrogen mineralization to assess local effective microorganisms’ role in nitrogen availability of swine effluent to forage crops. Applied Soil Ecology 2018, 130, 209 -218.
AMA StyleLaura Ney, Dorcas Franklin, Kishan Mahmud, Miguel Cabrera, Dennis Hancock, Mussie Habteselassie, Quint Newcomer. Examining trophic-level nematode community structure and nitrogen mineralization to assess local effective microorganisms’ role in nitrogen availability of swine effluent to forage crops. Applied Soil Ecology. 2018; 130 ():209-218.
Chicago/Turabian StyleLaura Ney; Dorcas Franklin; Kishan Mahmud; Miguel Cabrera; Dennis Hancock; Mussie Habteselassie; Quint Newcomer. 2018. "Examining trophic-level nematode community structure and nitrogen mineralization to assess local effective microorganisms’ role in nitrogen availability of swine effluent to forage crops." Applied Soil Ecology 130, no. : 209-218.
Flue gas desulfurization gypsum (FGDG) from coal-fired power plants is readily available for agricultural use in many US regions. Broiler litter (BL) provides plant available N, P, and K but can be a source of unwanted As, Cu, and Zn. As a source of Ca and S, FGDG can reduce losses of P and other elements in runoff from BL-amended areas. Rainfall simulation plots (2.0 m2) were established on a Piedmont Cecil soil growing ‘Coastal’ bermudagrass (Cynodon dactylon L.) for hay. Accumulation and transport of As, Cu, Cd, Cr, Hg, Pb, and Zn were evaluated after annual BL applications (13.5 Mg ha−1) with four FGDG rates (0, 2.2, 4.5, 9.0 Mg ha−1) and two FGDG treatments (0 and 9 Mg ha−1) without BL. Runoff As concentrations were sixfold greater with BL than without (P ≤ 0.01) and were similar to BL with FGDG at 2.2, 4.5 or 9.0 Mg ha−1 (P ≤ 0.10). Runoff concentrations of target elements did not increase where FGDG was applied alone. After three annual applications of FGDG and BL, soil concentrations of As, Cr, Pb, Hg, and Cu were well below levels of environmental concern. Our findings indicate that runoff losses of As from BL application are not reduced with FGDG but support other research indicating no identifiable environmental risks from FGDG beneficial use in agricultural systems. Copyright © 2018. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Harry H. Schomberg; Dinku M. Endale; Michael B. Jenkins; Rufus L. Chaney; Dorcas Franklin. Metals in Soil and Runoff from a Piedmont Hay Field Amended with Broiler Litter and Flue Gas Desulfurization Gypsum. Journal of Environmental Quality 2018, 47, 326 -335.
AMA StyleHarry H. Schomberg, Dinku M. Endale, Michael B. Jenkins, Rufus L. Chaney, Dorcas Franklin. Metals in Soil and Runoff from a Piedmont Hay Field Amended with Broiler Litter and Flue Gas Desulfurization Gypsum. Journal of Environmental Quality. 2018; 47 (2):326-335.
Chicago/Turabian StyleHarry H. Schomberg; Dinku M. Endale; Michael B. Jenkins; Rufus L. Chaney; Dorcas Franklin. 2018. "Metals in Soil and Runoff from a Piedmont Hay Field Amended with Broiler Litter and Flue Gas Desulfurization Gypsum." Journal of Environmental Quality 47, no. 2: 326-335.
Poultry litter (PL) is widely applied on grazing lands in Georgia. However, it is not clear how its long-term use affects soil microorganisms and their function. We examined changes in activity and community structure of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in a grazing land with a history of PL application and compared it to treatment with urea ammonium nitrate (UAN). Soil samples (0–15 cm) were collected in 2009 (after 15 yr of PL application) and in 2013 (after 2 yr of no application). The abundance and community composition of ammonia oxidizers (AO) were determined with molecular techniques that targeted amoA. Nitrification potential (NP) was used for measuring their activity. Abundance of AO was significantly higher in PL (7.41 and 7.10 log copies g soil−1 for AOB and AOA, respectively) than in UAN plots (6.82 and 6.50 log copies g soil−1 for AOB and AOA, respectively) in 2009. This is consistent with NP, which was higher in PL (0.78 mg NO3− –N kg−1 h−1) than in UAN (0.50 mg NO3−–N kg−1 h−1) plots in 2009. The abundance of AO and NP decreased in 2013. There was no treatment effect on the composition of AO. Correlation analysis suggested that AOB were functionally more important than AOA, indicating the need to target AOB for efficient management of N in PL-receiving soils. Overall, the difference in nitrification between PL and UAN was mainly caused by the change in AO abundance rather than composition, and AO were not negatively affected by an increase in PL-derived trace metal concentrations. Copyright © 2017. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Abha Mundepi; Jeanette Norton; Miguel Cabrera; Dorcas Franklin; Mussie Y. Habteselassie. Ammonia Oxidizers in a Grazing Land with a History of Poultry Litter Application. Journal of Environmental Quality 2017, 46, 994 -1002.
AMA StyleAbha Mundepi, Jeanette Norton, Miguel Cabrera, Dorcas Franklin, Mussie Y. Habteselassie. Ammonia Oxidizers in a Grazing Land with a History of Poultry Litter Application. Journal of Environmental Quality. 2017; 46 (5):994-1002.
Chicago/Turabian StyleAbha Mundepi; Jeanette Norton; Miguel Cabrera; Dorcas Franklin; Mussie Y. Habteselassie. 2017. "Ammonia Oxidizers in a Grazing Land with a History of Poultry Litter Application." Journal of Environmental Quality 46, no. 5: 994-1002.
Nicolás Wyngaard; Dorcas Franklin; Mussie Y. Habteselassie; Abha Mundepi; Miguel L. Cabrera. Legacy Effect of Fertilization and Tillage Systems on Nitrogen Mineralization and Microbial Communities. Soil Science Society of America Journal 2016, 80, 1262 -1271.
AMA StyleNicolás Wyngaard, Dorcas Franklin, Mussie Y. Habteselassie, Abha Mundepi, Miguel L. Cabrera. Legacy Effect of Fertilization and Tillage Systems on Nitrogen Mineralization and Microbial Communities. Soil Science Society of America Journal. 2016; 80 (5):1262-1271.
Chicago/Turabian StyleNicolás Wyngaard; Dorcas Franklin; Mussie Y. Habteselassie; Abha Mundepi; Miguel L. Cabrera. 2016. "Legacy Effect of Fertilization and Tillage Systems on Nitrogen Mineralization and Microbial Communities." Soil Science Society of America Journal 80, no. 5: 1262-1271.
A series of simulated rainfall-runoff experiments with applications of different manure types (cattle solid pats, poultry dry litter, swine slurry) was conducted across four seasons on a field containing 36 plots (0.75 × 2 m each), resulting in 144 rainfall-runoff events. Simulating time-varying release of Escherichia coli, enterococci, and fecal coliforms from manures applied at typical agronomic rates evaluated the efficacy of the Bradford–Schijven model modified by adding terms for release efficiency and transportation loss. Two complementary, parallel approaches were used to calibrate the model and estimate microbial release parameters. The first was a four-step sequential procedure using the inverse model PEST, which provides appropriate initial parameter values. The second utilized a PEST/bootstrap procedure to estimate average parameters across plots, manure age, and microbe, and to provide parameter distributions. The experiment determined that manure age, microbe, and season had no clear relationship to the release curve. Cattle solid pats released microbes at a different, slower rate than did poultry dry litter or swine slurry, which had very similar release patterns. These findings were consistent with other published results for both bench- and field-scale, suggesting the modified Bradford–Schijven model can be applied to microbial release from manure.
Keewook Kim; Gene Whelan; Marirosa Molina; S. Thomas Purucker; Yakov Pachepsky; Andrey Guber; Michael J. Cyterski; Dorcas Franklin; Ryan A. Blaustein. Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots. Journal of Water and Health 2016, 14, 443 -459.
AMA StyleKeewook Kim, Gene Whelan, Marirosa Molina, S. Thomas Purucker, Yakov Pachepsky, Andrey Guber, Michael J. Cyterski, Dorcas Franklin, Ryan A. Blaustein. Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots. Journal of Water and Health. 2016; 14 (3):443-459.
Chicago/Turabian StyleKeewook Kim; Gene Whelan; Marirosa Molina; S. Thomas Purucker; Yakov Pachepsky; Andrey Guber; Michael J. Cyterski; Dorcas Franklin; Ryan A. Blaustein. 2016. "Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots." Journal of Water and Health 14, no. 3: 443-459.
Dorcas Franklin; Damla Bender-Özenç; Nedim Ozenc; Miguel Cabrera. Nitrogen Mineralization and Phosphorus Release from Composts and Soil Conditioners found in the Southeastern United States. Soil Science Society of America Journal 2015, 79, 1386 -1395.
AMA StyleDorcas Franklin, Damla Bender-Özenç, Nedim Ozenc, Miguel Cabrera. Nitrogen Mineralization and Phosphorus Release from Composts and Soil Conditioners found in the Southeastern United States. Soil Science Society of America Journal. 2015; 79 (5):1386-1395.
Chicago/Turabian StyleDorcas Franklin; Damla Bender-Özenç; Nedim Ozenc; Miguel Cabrera. 2015. "Nitrogen Mineralization and Phosphorus Release from Composts and Soil Conditioners found in the Southeastern United States." Soil Science Society of America Journal 79, no. 5: 1386-1395.
Polyether ionophores, monensin, and salinomycin are commonly used as antiparasitic drugs in broiler production and may be present in broiler litter (bird excreta plus bedding material). Long-term application of broiler litter to pastures may lead to ionophore contamination of surface waters. Because polyether ionophores break down at low pH, we hypothesized that decreasing litter pH with an acidic material such as aluminum sulfate (alum) would reduce ionophore losses to runoff (i.e., monensin and salinomycin concentrations, loads, or amounts lost). We quantified ionophore loss to runoff in response to (i) addition of alum to broiler litter and (ii) length of time between litter application and the first simulated rainfall event. The factorial experiment consisted of unamended (∼pH 9) vs. alum-amended litters (∼pH 6), each combined with simulated rainfall at 0, 2, or 4 wk after litter application. Runoff from alum-amended broiler litter had 33% lower monensin concentration ( < 0.01), 57% lower monensin load ( < 0.01), 48% lower salinomycin concentration ( < 0.01), and 66% lower salinomycin load ( < 0.01) than runoff from unamended broiler litter when averaged across all events of rainfall. Ionophore losses to runoff were also less when rainfall was delayed for 2 or 4 wk after litter application relative to applying rainfall immediately after litter application. While the weather is difficult to predict, our data suggest that ionophore losses in runoff can be reduced if broiler litter applications are made to maximize dry time after application.
Sarah A. Doydora; Dorcas Franklin; Peizhe Sun; Miguel Cabrera; Aaron Thompson; Kimberly Love-Myers; John Rema; Vaughn Calvert; Spyros G. Pavlostathis; Ching-Hua Huang. Alum and Rainfall Effects on Ionophores in Runoff from Surface-Applied Broiler Litter. Journal of Environmental Quality 2015, 44, 1657 -1666.
AMA StyleSarah A. Doydora, Dorcas Franklin, Peizhe Sun, Miguel Cabrera, Aaron Thompson, Kimberly Love-Myers, John Rema, Vaughn Calvert, Spyros G. Pavlostathis, Ching-Hua Huang. Alum and Rainfall Effects on Ionophores in Runoff from Surface-Applied Broiler Litter. Journal of Environmental Quality. 2015; 44 (5):1657-1666.
Chicago/Turabian StyleSarah A. Doydora; Dorcas Franklin; Peizhe Sun; Miguel Cabrera; Aaron Thompson; Kimberly Love-Myers; John Rema; Vaughn Calvert; Spyros G. Pavlostathis; Ching-Hua Huang. 2015. "Alum and Rainfall Effects on Ionophores in Runoff from Surface-Applied Broiler Litter." Journal of Environmental Quality 44, no. 5: 1657-1666.
Gypsum has been shown to reduce runoff on soils prone to crust formation in the southeastern United States. Increased infiltration from gypsum applications could therefore help reduce runoff P and other nutrient losses from application of broiler litter (BL), a nutrient-rich fertilizer. In rainfall simulation experiments in June 2009 and May 2011, runoff and nutrient (N, P, Ca, Mg) losses in runoff were compared among treatments consisting of 0, 2.2, 4.5, and 9.0 Mg ha flue gas desulfurization gypsum (FGDG) combined with 13.5 Mg ha of BL and two control treatments of (0-0) and (9.0-0.0) Mg ha (FGDG-BL). A randomized block design with three replications was set up on a Cecil (Typic Kanhapludult) soil growing Coastal bermudagrass ( L.) for hay near Watkinsville, Georgia. Amendments were applied each April from 2009 to 2011. A reduction in runoff of 30% each year from the (9.0-13.5) compared with the (0-0) treatment was not statistically significant. Gypsum was effective in reducing concentration and load in one of the two study years: P and NH-N in 2009 (up to 83%) and NO-N in 2011 (up to 73%). A combination of factors related to weather extremes, timing of FGDG and BL applications, and their implication on soil and vegetation responses at different landscape positions might have caused the different responses between years. Additional studies focused on isolating the impacts of such factors would be helpful to ascertain the effectiveness of multiyear applications of FGDG as a best management practice to reduce P and other nutrient losses in soils of the southeastern United States.
Dinku M. Endale; Harry H. Schomberg; Dwight S. Fisher; Dorcas Franklin; Michael B. Jenkins. Flue Gas Desulfurization Gypsum: Implication for Runoff and Nutrient Losses Associated with Broiler Litter Use on Pastures on Ultisols. Journal of Environmental Quality 2014, 43, 281 -289.
AMA StyleDinku M. Endale, Harry H. Schomberg, Dwight S. Fisher, Dorcas Franklin, Michael B. Jenkins. Flue Gas Desulfurization Gypsum: Implication for Runoff and Nutrient Losses Associated with Broiler Litter Use on Pastures on Ultisols. Journal of Environmental Quality. 2014; 43 (1):281-289.
Chicago/Turabian StyleDinku M. Endale; Harry H. Schomberg; Dwight S. Fisher; Dorcas Franklin; Michael B. Jenkins. 2014. "Flue Gas Desulfurization Gypsum: Implication for Runoff and Nutrient Losses Associated with Broiler Litter Use on Pastures on Ultisols." Journal of Environmental Quality 43, no. 1: 281-289.
Flue gas desulfurization (FGD) gypsum is a byproduct of coal-fired power plants. Its application to agricultural fields may increase water infiltration, reduce soil erosion, and decrease nutrient losses from applications of animal manures. It may also reduce fecal bacterial contamination of surface waters. We tested the hypothesis that FGD gypsum applications would decrease the load of and the fecal indicator bacterium from poultry litter applications. Two rainfall simulation experiments were undertaken: one in spring 2009 and one in spring 2011. Six treatments consisted of four rates of FGD gypsum (0, 2.2, 4.5, and 9.0 Mg ha) with poultry litter (13.5 Mg ha and two controls) in a randomized, complete-block design with three replications. Each replicate 4- × 6-m plot contained a single 1- × 2-m subplot that was delineated by metal plates and a flume that captured total overland flow or runoff. Rainfall was applied at ∼64 mm h. Volume of overland runoff was measured and subsampled for analysis every 10 min for 1 h. Flow-weighted concentrations, total loads, and soil concentrations of were determined. was not detected in runoff. No significant differences between treatments were observed for the 2009 rainfall simulation. However, after 3 yr of FGD gypsum applications, the highest rate of FGD gypsum resulted in decreased flow-weighted concentrations and total loads of . Flue gas desulfurization gypsum applications may be a management practice that reduces microbial contamination of surface waters from manure applied to agricultural fields in the southeastern United States.
M. B. Jenkins; H. H. Schomberg; D. M. Endale; Dorcas Franklin; D. S. Fisher. Hydrologic Transport of Fecal Bacteria Attenuated by Flue Gas Desulfurization Gypsum. Journal of Environmental Quality 2014, 43, 297 -302.
AMA StyleM. B. Jenkins, H. H. Schomberg, D. M. Endale, Dorcas Franklin, D. S. Fisher. Hydrologic Transport of Fecal Bacteria Attenuated by Flue Gas Desulfurization Gypsum. Journal of Environmental Quality. 2014; 43 (1):297-302.
Chicago/Turabian StyleM. B. Jenkins; H. H. Schomberg; D. M. Endale; Dorcas Franklin; D. S. Fisher. 2014. "Hydrologic Transport of Fecal Bacteria Attenuated by Flue Gas Desulfurization Gypsum." Journal of Environmental Quality 43, no. 1: 297-302.
Georgia farmers are increasing preemergence applications of soil residual herbicides to control glyphosate resistant weeds. To improve efficacy these herbicides are often activated by post-application irrigation. Broiler litter is commonly applied to fields before these herbicides. The herbicide wetting-in practice increases surface soil water content and may increase runoff and transport of broiler litter borne fecal bacteria into surface waters during subsequent storm events. Our objective was to determine differences in loads of fecal bacteria, Escherichia coli and Salmonella spp., in runoff from conventional tillage (CT) and no-till (NT) systems after herbicides were watered into an Ultisol fertilized with broiler litter. On replicated 6 m2-plots (n = 3) simulated rainfall was applied for 70 min with composite runoff samples collected every 5 min and analyzed for E. coli and Salmonella spp. Although total runoff volume from the CT plots was significantly greater than from NT plots, no significant differences in total load of E. coli and Salmonella or the percent of total loads of E. coli and Salmonella recovered in runoff between tillage systems were observed. Total percentage of Salmonella recovered in runoff from both tillage systems was, however, four log10 orders of magnitude greater than the percentage of E. coli that was recovered. Difference in percentage recovered between the fecal indicator bacterium, E. coli, and the pathogen, Salmonella, underscores an apparent difference in hydrologic transport characteristics of these two fecal bacteria and casts doubts on the efficacy of E. coli as an indicator of risk to public health.
M.B. Jenkins; C.C. Truman; D.H. Franklin; T.L. Potter; D.D. Bosch; T.C. Strickland; R.C. Nuti. Fecal bacterial losses in runoff from conventional and no-till pearl millet fertilized with broiler litter. Agricultural Water Management 2013, 134, 38 -41.
AMA StyleM.B. Jenkins, C.C. Truman, D.H. Franklin, T.L. Potter, D.D. Bosch, T.C. Strickland, R.C. Nuti. Fecal bacterial losses in runoff from conventional and no-till pearl millet fertilized with broiler litter. Agricultural Water Management. 2013; 134 ():38-41.
Chicago/Turabian StyleM.B. Jenkins; C.C. Truman; D.H. Franklin; T.L. Potter; D.D. Bosch; T.C. Strickland; R.C. Nuti. 2013. "Fecal bacterial losses in runoff from conventional and no-till pearl millet fertilized with broiler litter." Agricultural Water Management 134, no. : 38-41.