Poultry litter on agricultural lands could introduce nitrogen (N), phosphorus (P), heavy metals in soil and ground water. Native vegetations were identified to assess efficacy for phytoremediation of nutrients and metals from soil and water. Objective was to measure capability of multi-year native species to remove metals, nutrients, and prevent Nitrate-N leaching below the rooting zone. Treatments were distributed in four replicates with/without fertilization. Suction lysimeters were installed at 30, 60, and 90-cm depths in 3 of 4 replicates. Species were identified, recorded, five specified cuttings sampled. Plant, soil, water samples were prepared and analyzed by spectroscopy. Nitrate-N extraction, nitrates in water samples were determined using flow injection analysis. Fertilized plots (NVM) had 39% more biomass yield than unfertilized plots (NVN). In plants, nutrient and metal concentrations varied significantly with 14% increase in Zn, 36% and 26% in K and Mg over NVN for first and second year. Uneven between NVM and NVN, topsoil had higher values for most nutrients and metals. Largest P and (NO3-)-N in plant and water were observed from NVM. Cultivation of native vegetation appears to be an effective approach for remediation of excess nitrates-N, P, heavy metals from surface and sub-surface zones of the soil. NOVELTY STATEMENTNative vegetation has been used for soil fertility, specific reasons like the removal of pesticides or agrochemicals, and other chemical related exposures. Studies on the use of native vegetation for phytoremediation on agricultural lands are uncommon. This research looked at the capability of native vegetation of different species as a viable tool for the remo+val of excess nutrients and heavy metals from agricultural lands. Results indicated native vegetation can take up significant amounts of excess nutrients from soils, proportional to their biomass accumulation. Native Vegetation was therefore found to be a nutrient sink, capable of removing excess nutrients/metals from the soil.

Water and sediment transport and redistribution around drainage ways are major riparian zone processes that affect soil chemistry and water quality of watersheds. This is more so for urbanized watersheds that generate more runoff and sediments which end up in the drainage ways. This study was done to evaluate the pedogeomorphic variability of the Aldridge Creek Watershed in Alabama, and to assess its impact on the water quality and soil properties of the watershed. Sampling locations along the creek were subdivided into five stream sites and geo-referenced. Soil samples from the riparian buffers and water samples from the creek were collected from upstream, midstream, and downstream sites of the watershed and analyzed for trace metal concentration and distribution. The trace metal concentration in soils of the riparian buffers varied from 20 to 34 µg g−1 for lead (Pb), 50–85 µg g−1 for zinc (Zn), 6–17 µg g−1 for copper (Cu), 11–18 µg g−1 for nickel (Ni) and 5–21 µg g−1 for arsenic (As). At all sites, Pb, Zn, Ni, Cu and As concentrations in the riparian zone locations were 7–67% higher than the upper slopes indicating that the riparian zone is a potential source or sink of trace metals along the flow pathways between the upper slope soils and the stream. While there were significant differences in the distribution of trace metals in soils between the upslope and riparian zone locations at the upstream, midstream, and downstream sites, there was no significant difference in the stream water trace metals concentration between the sites of the watershed.

Poultry litter and fertilizers are normally added as soil amendments. The effects of poultry litter and inorganic fertilizers on three mixed-season perennial forages were studied for two years in the field to understand growth dynamics, metals, and nutrient uptake. The primary objective was to investigate the heavy metal and nutrient concentrations, biomass yield and forage potential of a cool-season forage, stinging nettle (Urtica dioica L.), relative to warm-season forages, bermudagrass (Cynodon dactylon (L.) Pers.) and switchgrass (Panicum virgatum L.). Forage cuttings and soil samples were analyzed for heavy metals and nutrients using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Total biomass yield was higher by 66% and 50% in switchgrass and bermudagrass, respectively, compared with stinging nettle for the first year. While the warm-season forages yielded more biomass over the cool-season forage, metal concentrations were significantly higher for all elements in the cool-season forage. Stinging nettle showed greater macro-nutrient uptake with 103.20 kg ha−1, 0.87 kg ha−1, 27.49 kg ha−1 and 32.08 kg ha−1 for Ca, Fe, Mg, and P, except for K with 223.51 kg ha−1 compared with 267.29 kg ha−1 and 283.96 kg ha−1 for switchgrass and bermudagrass, respectively. Heavy metals were also higher in stinging nettle but were within the allowable limits for forages, indicating its potential as a resource for forages and nutrient cycling, particularly when double-cropped with warm-season forages.

Byproducts have been used in agriculture to improve soil properties and provide plant nutrients. This study utilized flue gas desulfurization gypsum (FGDG), biochar, bed ash, broiler litter ash (BLA) and their combinations on the amelioration of soil acidity. Calcium carbonate (CaCO3) was used as the lime source and alfalfa as the test crop. While amendments increased alfalfa shoot and root yields as well as tissue Ca concentration, the tissue concentrations of copper, manganese, lead and zinc did not increase with amendment. Bed ash was as effective as CaCO3 in reducing soil acidity to a depth of 36 cm while calcium in the FGDG was more soluble than Ca in the CaCO3. With the increased alfalfa yield and the reduced tissue metal concentrations when these byproducts were used, this demonstrates that at the rate used in this study, these byproducts could be use as amendment on acidic soils.

Biosolids are used to improve soil physical and chemical properties. Analysis of biosolids-amended soils from multiple regions of United States using consistent analytical methods is lacking. This Study determined long-term biosolids application on soil pH, electrical conductivity (EC), carbon, cadmium, copper, lead, and zinc concentrations in soils from two regions in United States. At one region, little difference was observed in pH and EC between biosolids-amended surface soils and control, the second region ranged from 5.46 to 7.87 and 50.2 to 402 mu S cm(-1) respectively. Trace metal levels at this region ranged from 0.76 to 3.79, 8.7 to 54.1, 15.2 to 53.9, and 26 to 207 mg kg(-1) for Cadmium, Copper, lead and Zinc respectively; with its carbon levels ranging from 14.5 to 90.0 g kg(-1). Metal levels were within the standards for residential occupation with the 40 Code of Federal Regulations (CFR) Part 503 and should not affect soil and groundwater quality.

Arsenic (As) accumulation in rice grain is a significant public health concern. Inorganic As (iAs) is of particular concern because it has increased toxicity as compared to organic As. Irrigation management practices, such as alternate wetting and drying (AWD), as well as genotypic differences between cultivars, have been shown to influence As accumulation in rice grain. A 2 year field study using a Lemont × TeQing backcross introgression line (TIL) mapping population examined the impact of genotype and AWD severity on iAs grain concentrations. The “Safe”-AWD [35–40% soil volumetric water content (VWC)] treatment did not reduce grain iAs levels, whereas the more severe AWD30 (25–30% VWC) consistently reduced iAs concentrations across all genotypes. The TILs displayed a range of iAs concentrations by genotype, from less than 10 to up to 46 μg kg –1 under AWD30 and from 28 to 104 μg kg –1 under Safe-AWD. TIL grain iAs concentrations for flood treatments across both years ranged from 26 to 127 μg kg –1 . Additionally, seven quantitative trait loci (QTLs) were identified in the mapping population associated with grain iAs. A subset of eight TILs and their parents were grown to confirm field-identified grain iAs QTLs in a controlled greenhouse environment. Greenhouse results confirmed the genotypic grain iAs patterns observed in the field; however, iAs concentrations were higher under greenhouse conditions as compared to the field. In the greenhouse, the number of days under AWD was negatively correlated with grain iAs concentrations. Thus, longer drying periods to meet the same soil VWC resulted in lower grain iAs levels. Both the number and combinations of iAs-affecting QTLs significantly impacted grain iAs concentrations. Therefore, identifying more grain iAs-affecting QTLs could be important to inform future breeding efforts for low iAs rice varieties. Our study suggests that coupling AWD practices targeting a soil VWC of less than or equal to 30% coupled with the use of cultivars developed to possess multiple QTLs that negatively regulate grain iAs concentrations will be helpful in mitigating exposure of iAs from rice consumption.

Background: Emerging evidence suggests social, health, environmental, and economic benefits of urban agriculture (UA). However, limited work has characterized the risks from metal contaminant exposures faced by urban growers and consumers of urban-grown produce. Objectives: We aimed to answer community-driven questions about the safety of UA and the consumption of urban-grown produce by measuring concentrations of nine metals in the soil, irrigation water, and urban-grown produce across urban farms and gardens in Baltimore, Maryland. Methods: We measured concentrations of 6 nonessential [arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni)] and three essential [copper (Cu), manganese (Mn), zinc (Zn)] metals in soil, irrigation water, and 13 types of urban-grown produce collected from 104 UA sites. We compared measured concentrations to existing public health guidelines and analyzed relationships between urban soil and produce concentrations. In the absence of guidelines for metals in produce, we compared metals concentrations in urban-grown produce with those in produce purchased from farmers markets and grocery stores (both conventionally grown and U.S. Department of Agriculture–certified organic). Results: Mean concentrations of all measured metals in irrigation water were below public health guidelines. Mean concentrations of nonessential metals in growing area soils were below public health guidelines for Ba, Cd, Pb, and Ni and at or below background for As and Cr. Though we observed a few statistically significant differences in concentrations between urban and nonurban produce items for some combinations, no consistent or discernable patterns emerged. Discussion: Screening soils for heavy metals is a critical best practice for urban growers. Given limitations in existing public health guidelines for metals in soil, irrigation water, and produce, additional exposure assessment is necessary to quantify potential human health risks associated with exposure to nonessential metals when engaging in UA and consuming urban-grown produce. Conversely, the potential health benefits of consuming essential metals in urban-grown produce also merit further research. https://doi.org/10.1289/EHP9431

Background and Objectives: It is believed that the poultry litterʼs nutrient composition is influenced by management.However, limited information exists on whether current poultry litter management strategies influence litter nutrients.To fill this knowledge gap, Alabama poultry producers were surveyed to evaluate their management strategies and asked to submit a litter sample to determine how their production practices impacts poultry litter and its nutrient composition.Specifically, this study assessed the frequency of cleanout, the depth of sampling, the size of birds reared and the number of flocks raised on the bedding to determine how it influenced macro and micro nutrient concentrations of the litter.Materials and Methods: The influence of poultry rearing facility (broiler, breeder, or pullet) and whether the litter was collected from a poultry house, composter or dry stack barn was also evaluated.A total of 188 L samples submitted by producers were used for this study.Results: Averaging across all samples collected, the litter on an as-is basis had a fertilizer grade close to that of 3-3-2 for N, P 2 O 5 and K 2 O, respectively.Litter collected from broiler production facilities had the highest overall macro-and micronutrient concentrations, while litter from composters had slightly higher N, P and Ca and lower C than litter taken directly from houses or drystack barns.The depth sampled, frequency of cleanout and number of flocks on the litter also influenced nutrient composition.Nutrients tended to be higher in caked litter than from sampling the entire six-inch depth.Litter nutrients tended to increase with flocks and decrease with frequency of cleanout.Conclusion: This study shows that differences in management may influence litter nutrient concentrations.

Although soil amended with biosolids can improve soil properties, heavy metal uptake by vegetable crops grown on biosolids-amended soil is of concern. This study evaluated the effects of biosolids and flue gas desulfurization gypsum (FGDG) on yield and metal uptake of two consecutive crops of lettuce. A soil was amended with limed or composted biosolids at rates of 40 and 80 T ha(-1) with and without 10 T ha(-1) FGDG or with FGDG alone. At both harvests, lettuce yield was higher, compared with the unamended control, in all biosolids treatments, whereas FGDG alone did not significantly affect yield. Lettuce lead concentration was below instrument detection limits. Copper, manganese and zinc concentrations were highest in plants grown in the composted biosolids treatments for the first crop. Cadmium and copper were highest in the limed biosolids in the second. In all cases metal concentrations, did not exceed the range found in lettuce.

A major constraint for crop production on disturbed soils is phosphorus (P). A 2-year field study was conducted on a disturbed soil to evaluate broiler litter ash (BLA) as an inexpensive phosphorus fertilizer for soybean. BLA or super phosphate (SP) was applied at four rates and planted with soybean followed by wheat. At soybean growth stage R3, two plants from each plot were removed for tissue analysis. Soybean tissue P concentration distributions were in the order pods > leaves > stems > roots. At maturity, soybean grain and wheat tissue yields were not significantly affected by P source. Except for the high superphosphate rate for the second crop, P concentrations of soybean grain and wheat tissue were not significant between P source. In this study, BLA was as effective as SP for growth of soybean grain and wheat tissue, suggesting that BLA can be used as an inexpensive P fertilizer on low P disturbed soils.

Copper ions at proper levels are essential for plant cell growth and excess copper ions are toxic to root cell growth. The one meter height Theobroma cacao L. plants have roots in 10-15 cm depth nursery pots. “SpinOut®” high in Cu+2 and painted inside the plastic container mitigates against root encircling. Evidence is presented that a similar physicochemical effect can be obtained by incorporating copper ions into a keratin biopolymer matrix extruded into pellets and injection molded into a pot. Sustained controlled release of Cu+2 is obtained for at least six months. The same technology enables highly uniform delivery of the same amount of micronutrients self-consistently pot to pot. This approach would be useful in urban agriculture in which the biomass formulated composition of a soil matrix is especially non-uniform and in which both the plant and the surrounding soil matrix can be competing from among the same micronutrients.

Accumulation of lead (Pb) and arsenic (As) in peanut grown on Pb/As-contaminated soils amended with two sources of phosphorus (P) was investigated. An urban soil and an orchard soil with Pb concentrations of 1120 and 272, and As concentrations of 6.9 and 90mg kg(-1), respectively, were amended with three rates (0, 56, and 112kg ha(-1)) of P supplied as broiler litter ash or superphosphate and planted with peanuts. At harvest, peanut kernel As concentration was 2.9mg kg(-1) on the orchard soil and 0.003mg kg(-1) on the urban soil. Kernel As was not significantly affected by P source and was not significantly different between the normal and high P rates. Kernel Pb concentration was below the instrument detection limit in all cases. Land with history of arsenic or lead-arsenate application should be tested for As before used for peanut production.

Rising concentrations of atmospheric carbon dioxide [CO2] could, potentially, increase contaminant uptake and the overall efficiency of phytoremediation. To determine the ability of elevated [CO2] to sequester arsenic (As), five Arabidopsis thaliana ecotypes were grown at ambient (approximate to 400 mu mol mol(-1)) and elevated (approximate to 800 mu mol mol(-1)) CO2 at three levels of As concentration (0, 50, and 110 mu M) to determine whether: (a) elevated CO2 increased the concentration of As in above-ground biomass (AGB), and, (b) the effect of [CO2] on As concentration was ecotype specific. We found that elevated CO2 significantly increased AGB of A. thaliana, but the extent of biomass stimulation was specific to ecotype. Overall, at the highest As concentration, the relative effect of elevated [CO2] was to reduce both As concentration and As uptake per plant; however, genetic variation was also evident among A. thaliana in regard to phytoextraction of As at current and projected CO2 levels.

ABSTRACT Although biosolids are a rich source of plant nutrients, there is concern about the potential heavy metal uptake by crops grown on biosolid-amended soils. This study was conducted to determine the effects of limed or composted biosolids and flue gas desulfurization gypsum (FGDG) on edamame growth, nodule development, and metal uptake. Two consecutive crops of edamame were grown on 40 and 80 T ha−1 biosolid-amended soil with and without 10 T ha−1 FGDG. Biosolids with or without FGDG did not reduce biomass, nodules, or grain yields in the first harvest and increased yields of all three tissues in the second harvest. Lead and cadmium concentrations in grain and biomass were below the instrument detection limits. Copper, manganese, and zinc were within the ranges normally found in soybean grain. In this pot study, biosolids and FGDG did not reduce edamame growth or increase grain metal concentrations to levels of concern.

ABSTRACT Ethnic vegetable crops are increasingly being grown in the United States and may accumulate heavy metals when grown on urban soils. This study evaluated accumulation of lead (Pb) and arsenic (As) in tissues of Malabar spinach (Basella alba L.) and sweet potato (Ipomoea batatas L.) grown on an urban and an orchard soil with Pb concentrations of 1,120 and 272 mg kg−1, respectively, and As concentrations of 6.92 and 90 mg kg−1, respectively. Tissue Pb was higher in both crops grown on both contaminated soils compared with an uncontaminated soil, while tissue As was higher on the orchard soil only. Malabar spinach did not accumulate Pb or As in its shoot, but concentrations of both metals were higher in sweet potato stems compared to leaves or tubers. Consumption of sweet potato stems should be avoided when sweet potato leaves are grown as a vegetable on soils with elevated levels of Pb and As.

Lead concentrations in soil organisms are usually well below those in the associated soil and tend to decrease with each higher trophic level in a food chain. Earthworms of the species Eisenoides lonnbergi provide an exception to this observation, accumulating very high concentrations of lead from acidic soils. Earthworms belonging to this species were collected from strongly to extremely acidic soils at 16 sites on a wildlife refuge in Maryland, USA. A lead concentration as high as 766 mg/kg, dry weight, was detected in depurated E. lonnbergi collected from soil containing only 17 mg/kg of lead. Concentration factors (ratio of lead concentration in earthworms to lead concentration in soil, dry wt) were highly variable at the sites, from 1.0 to 83. As suggested previously, lead absorption by earthworms is enhanced in low-calcium soils. The anomalously high concentrations of lead found in E. lonnbergi are more closely correlated with the uptake of calcium from acidic soils than with bioaccessibility of soil lead. Environ Toxicol Chem 2018;37:914-919. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Rice (Oryza sativa L.), a staple crop for over 50% of the world's population, is also a source of dietary arsenic (As) because of it's efficiencyat accumulating As. Lead-arsenate pesticide was used in agriculture, these soils potentially may be used for rice production. The objective of this study was to determine the effects of compost on total and inorganic As concentrations in rice grown on lead-arsenate contaminated soils. Three lead-arsenatesoils were amended with 10% by weight of compost and planted with rice under flooded and non-flooded conditions. Rice grain yieldwas higher with compost but not flooding. Flooding significantly increased total and inorganic As concentrations. In most cases, rice inorganic Asconcentrations were higher than the limit set by Chinaat 0.2mg kg(-1). Compost at therate used did not reduce rice grain As to safe levels.Lead-arsenate contaminated soils are not recommended for rice production.

Ammonium nitrate is a fertilizer and an explosive. Encapsulation of ammonium nitrate (NH4NO3) with coal combustion byproducts (fly ash or flue gas desulfurization gypsum) reduces the explosiveness of NH4NO3. A field study was conducted to determine the effects of encapsulated NH4NO3 on corn (Zea mays L.) and rye (Secale cereal L.) yield and accumulation of nitrogen (N), arsenic (As), cadmium (Cd), iron (Pb), copper (Cu), manganese (Mn), and zinc (Zn). Nitrogen rates were 56 and 112kg ha(-1). Yields and concentrations of N and metals in corn grain, ear-leaf, and stover and in rye shoots were not affected by N source. Increased N rate resulted in increased corn ear-leaf, grain, and stover N, ear-leaf Cu, Mn, and Zn, and rye shoot yield, Cu, and Zn. For both species, metal levels did not exceed normal ranges. Coal byproduct-encapsulated NH4NO3 is as effective as non-encapsulated NH4NO3 for corn or rye production, without increasing plant metal concentrations above normal levels.

Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor arsenic in rice plants. Four arsenic levels were induced in hydroponically grown rice plants with application of 0, 5, 10 and 20 µmol·L−1 sodium arsenate. Reflectance spectra of upper fully expanded leaves were acquired over visible and infrared (NIR) wavelengths. Additionally, canopy reflectance for the four arsenic levels was simulated using SAIL (Scattering by Arbitrarily Inclined Leaves) model for various soil moisture conditions and leaf area indices (LAI). Further, sensitivity of various vegetative indices (VIs) to arsenic levels was assessed. Results suggest that plants accumulate high arsenic amounts causing plant stress and changes in reflectance characteristics. All leaf spectra based VIs related strongly with arsenic with coefficient of determination (r2) greater than 0.6 while at canopy scale, background reflectance and LAI confounded with spectral signals of arsenic affecting the VIs’ performance. Among studied VIs, combined index, transformed chlorophyll absorption reflectance index (TCARI)/optimized soil adjusted vegetation index (OSAVI) exhibited higher sensitivity to arsenic levels and better resistance to soil backgrounds and LAI followed by red edge based VIs (modified chlorophyll absorption reflectance index (MCARI) and TCARI) suggesting that these VIs could prove to be valuable aids for monitoring arsenic in rice fields.