bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating the Availability of Nitrogen in Poultry Manure through Laboratory and Field Studies
Authors: Bitzer Carolyn C. , Sims J. Thomas
Published: July 2010

Excessive applications of poultry (chicken, Gallus gallus domesticus) manure in some cropping systems have resulted in nitrate contamination of groundwater. To determine the application rates necessary for optimum crop growth and minimal nitrate leaching, estimates of the availability of N in poultry manure are necessary. This research investigated, under laboratory and field conditions, an approach that could be used to predict available N in poultry manure. In the laboratory study, 20 manures were incorporated with a Kalmia sandy loam (Typic Hapludults) at rates estimated to provide 100 mg predicted available N (PAN) kg−1 soil, where PAN = 80% Ni + 60% No and Ni = (NH4‐N + NO3‐N), No = (Total N − Ni). Actual available N, defined as Ni initially extractable by 2 M KCl, plus N mineralized during a 140‐d nonleached incubation study, ranged from 54 to 118 mg N kg−1 soil. A field study was also conducted at two locations comparing three poultry manures, applied at rates of 0, 90, 180, and 270 kg PAN ha−1, with ammonium nitrate (AN) applied at the same rates. Irrigated corn (Zea mays L.) was grown at both sites during 1985 and soil, plant, and yield data were obtained. Nitrogen content of ear leaf samples at mid‐silking was significantly less, at both sites, for the three manures than for AN. No significant differences in grain yields were observed between N sources at site one, but average yields (across N rate) were significantly less with two of the poultry manures (PM‐7, PM‐11), relative to AN, at site two. Postharvest soil samples (0–100 cm) were obtained from the control (0N) and 270 kg PAN ha−1 rates of all N sources. Residual Ni was less than 10 mg kg−1 for all treatments and depths; however, significantly higher (P = 0.08) NO3‐N levels were found with AN at the 60 to 80 depth cm at site two and at the 80 to 100 cm (P < 0.05) depths at sites one and two. The field study was repeated at the same sites in 1986 to assess the residual N value of manure applied in 1985. Based on ear leaf N and grain yields, residual available N from manures was determined to be less than 45 kg N ha−1. The second year decay constant for PM was estimated, by comparison with AN yields, to be 0.11 and 0.06 at sites one and two, respectively.
Effects of Acid Rain on Corn Silks and Pollen Germination
Authors: Wertheim Frank S. , Craker Lyle E.
Published: July 2010

Pollen germination was significantly reduced on corn (Zea mays L. cv. Pioneer 3747) silks exposed to an episode of simulated acid rain of pH 4.6, 3.6, or 2.6 as compared with germination on silks treated with pH 5.6 rain. Silks treated with a simulated acid rain of pH 3.6 or 2.6 developed necrotic lesions in the most distal regions. When silk tissue was immersed in a simulated acid rain of pH 3.6, the development of necrosis in the tip region was related to the duration of the exposure. Silk tissue placed in a simulated acid rain solution was able to buffer the acidity of the rain over time.
Some Observations on the Stoichiometry of Feldspar Hydrolysis in Granitic Soil
Authors: Clayton James L.
Published: July 2010

Weathering rates of orthoclase and plagioclase were computed from mass balances of Na, K, and Ca in three forested watersheds in the Idaho batholith. On the basis of stand conditions, two watersheds were assumed to have no net gains or losses of cations in biomass, and increases in biomass were measured in the third watershed. Balanced feldspar hydrolysis reactions were established based on kaolinite as a weathering product. Free silica (SiO2) release predicted from reaction stoichiometries ranged from 94 to 99% of measured SiO2 flux from the watersheds. These results suggest that the entire flux of Na, K, and Ca can be attributed to cation release from primary mineral hydrolysis without invoking net loss of cations from exchange sites in these watersheds. The acid neutralizing capacity (ANC) arising from hydrolysis is approximately 1500 to 1700 mol(c) ha−1 yr−1. Annual H+ input from bulk precipitation currently averages 70 mol ha−1 yr−1. Attempts by other researchers to check reaction stoichiometry by SiO2 have not been particularly successful. Simple mineralogy of parent material and lack of anthropogenic sources of acid deposition may explain why predicted and actual SiO2 fluxes were similar in this study.
Boron Release and Sorption by Fly Ash as Affected by pH and Particle Size
Authors: Hollis J. F. , Keren R. , Gal M.
Published: July 2010

The effect of ash particle size, pH, and Ca(OH)2 presence on the dissolution and adsorption of B by fly ash in aqueous media was studied. Most of the soluble B was found in the small particles of ash. Dissolution of B was independent of the dissolution of Ca from fly ash. Decreasing the pH from 12.5 to 6 increased both the solubility and the extractability of B. A small amount of B was adsorbed by fly ash at pH 7; this was attributed to a ligand exchange mechanism. Sorption of B increased with increasing pH, up to 12, which could not be explained by ligand exchange but rather with coprecipitation with CaCO3.
Yield Responses of Field‐Grown Crops to Acidic Fog and Ambient Ozone
Authors: Takemoto B. K. , Olszyk D. M. , Johnson A. G. , Parada C. R.
Published: July 2010

The yield responses of five commercially important California crops (strawberry Fragaria × ananassa Duch., tomato Lycopersicon esculentum Mill., pepper Capsicum annuum L., alfalfa Medicago sativa L., celery Apium graveolens L.) to acidic fog singly, and in combination with ambient O3 were examined under field conditions, utilizing open‐top chambers and air exclusion systems. Simulated fog at pH 7.24, 2.69, or 1.68 was applied to plants twice weekly for 11 weeks. Only repeated applications of pH 1.68 fog were found to cause significant alterations in crop injury or yield responses compared to exposure to pH 7.24 fog. Necrotic lesions developed on leaves, flowers, and fruits of plants exposed to pH 1.68 fog, but not on plants exposed to pH 2.69 or 7.24 fog, or on unfogged plants. In plants grown in open‐top chambers, pH 1.68 fog significantly reduced fruit yield in strawberry, tomato, and pepper by 30 to 58%, and biomass yield in alfalfa by 11% relative to yields measured in crops exposed to pH 7.24 fog. Moreover, significant yield reductions were observed in tomato, pepper, alfalfa, and celery exposed to ambient O3 compared to crops grown in charcoal‐filtered air. The combined effects of highly acidic fog (pH 1.68) and ambient O3 were additive with respect to growth and yield responses in all five crops grown in open‐top chambers. However, since fog at current ambient levels of acidity is typically 10 to 100 times less acidic, yield losses attributable to acidic fog alone, are not likely to occur. Alternatively, yield reductions may result as a consequence exposure to ambient O3, but no interactive effect would be expected based on the results of the present study. Plant yield, growth, and injury responses to acidic fog and ambient O3 in air exclusion system plots were not similar to those exhibited by plants grown in open‐top chambers. The impacts of the applied stresses were less pronounced in plants grown in air exclusion systems, which may have been partly due to differences in environmental conditions between the exposure methodologies.
Chemical Volatilization in Nearly Dry Soils under Non‐Isothermal Conditions
Authors: Cohen Yoram , Taghavi Hutan , Ryan Patrick A.
Published: July 2010

A theoretical investigation of the volatilization of chemical contaminants in the top layer of a nearly dry soil column under nonisothermal conditions is presented in this paper. The proposed one‐dimensional model considers the effect of natural convection, and the variations of diffusivity and vapor phase adsorption with temperature on contaminant flux across the soil‐air interface. The study has shown that natural convection effects are small. Diurnal temperature changes were found to lead to fluctuations in the concentration profiles and the volatilization flux due to alternating adsorption/desorption processes in the soil. These diurnal changes in concentration cannot be determined from isothermal calculations. Finally, it is suggested that a simple linear isothermal diffusion model may be adequate for describing the chemical concentration profiles at times that are sufficiently long past the initial soil contamination event.
Forest Harvest and Site Preparation Effects on Stormflow and Peakflow of Ephemeral Streams in the Ouachita Mountains
Authors: Miller E. L. , Beasley R.S. , Lawson E. R.
Published: July 2010

Stormflow and peakflow response to three silvicultural treatments—clearcutting, selection cutting and no disturbance (control)—were compared in a replicated small watershed study in the Ouachita Mountains of Arkansas. Watersheds were blocked according to aspect, location, soils, and geology in a randomized complete block design to test effects of treatments. Soils on the watersheds are shallow and were derived from sandstones and shale parent materials. Annual precipitation totals ranged from 72 to 142% of the long‐term average (131.7 cm) during the study and a single rainstorm exceeding the 100‐yr, 24‐h event occurred the second year following harvest treatments. Overall, stormflow water yields did not increase significantly due to forest harvest treatments apparently because permeable soils and subsurface geology allowed deep seepage at the expense of Stormflow. However, a treatment response was observed within one block and there was clearly a difference in Stormflow response between blocks of watersheds. Annual stormflow as a percentage of precipitation ranged from 2 to 59% across watersheds and years. Overall peakflows did not increase significantly due to treatment, but a treatment response was obseved within one block of watersheds and there was a significant difference in peakflows between blocks. Treatment differences in Stormflow and peakflow for the 100‐yr event were not significant. Stormflow to precipitation ratios for this event ranged from 0.63 to 0.81.
Persistence and Movement of Picloram in a Northern Saskatchewan Watershed
Authors: Smith A. E. , Waite D. , Grover R. , Kerr L. A. , Milward L. J. , Sommerstad H.
Published: July 2010

In the summer of 1982, 477 ha of a weapons range in northern Saskatchewan were treated with a granular formulation of picloram (4‐amino‐3,5,6‐trichloropicolinic acid) at a rate of 3.38 kg ha−1 (a.i.). For the next 2 yr, the persistence of picloram was monitored in the soil at sites within and outside the treatment area. Picloram was monitored for a 3‐yr period in the groundwater at off‐target sites and in the surface waters and sediments of a creek and two lakes adjoining the treatment area. Extensive leaching of the herbicide was noted. After 14 months residues were recovered from the 60‐ to 90‐cm soil depths, and after 22 months from the 90‐ to 120‐cm soil layer. After 26 months between 138 and 396 g ha−1 of picloram were recovered from the top 120‐cm soil depths, Picloram was detected in the top 30 cm of soils, approximately 1 km from the treatment area, when sampled 14 and 22 months following the initial application. Picloram (0.25–88.3 µg L−1) was recovered after 35 months from groundwater samples collected at 120 cm from the same off‐target sites. This transfer to nontreated sites was considered to result from a combination of blowing surface soil and groundwater movement from the treated area. Samples of surface waters taken from a lake approximately 1 km from the treatment zone indicated that picloram residues could be detected (0.1–1.15 µg L−1) in the falls of 1983 and 1984, but not in the summers of 1984 and 1985. Traces of picloram (0.14–0.39 µg L−1) were recovered in the fall of 1983 and summer of 1985 in creek waters situated approximately 300 m from the edge of the treatment area. Picloram was detected (12 µg kg−1) in only one lake sediment sample at one sampling period.
Lichens, Tree Growth, and Foliar Symptoms of Air Pollution: Are the Stories Consistent?
Authors: Muir Patricia S. , McCune Bruce
Published: July 2010

Lichen communities, tree growth, and foliar symptoms of Acer saccharum, Fraxinus spp., Liriodendron tulipifera, Quercus aiba, and the Quercus rubra group were studied in relation to air pollutants in southern Indiana and Illinois. Both study areas receive regional pollutants, but only one is close to a large coal‐fired utility, which results in a high dose of SO2 and its reaction products. Lichen communities differed significantly between the two areas; species richness and total cover were lowest in the near‐utility area, and species compositional differences suggested that air quality was responsible. Few differences were noted in foliar symptoms between areas; when symptom levels differed, they were generally highest in the remote area. Ozone‐induced stippling was found in both areas on leaves of Fraxinus spp. and Liriodendron. Although ring widths indicated depressed tree growth in the near‐utility area during years of high emissions, periodic basal area increments and tree vigor did not generally differ between areas, and were generally not related to foliar symptoms other than stippling. Ozone‐induced stippling on Liriodendron was negatively correlated with basal area increments.
The Distribution of Natural Radionuclides in Native Soils of Southern Saskatchewan, Canada
Authors: Kiss J. J. , de Jong E. , Bettany J. R.
Published: July 2010

Little information is available on the regional distribution of natural radionuclides in agricultural environments. Surface soil samples were collected from uncultivated, unfertilized sites in the agricultural area of Saskatchewan, Canada, and analyzed for 40K, and daughters of 238U and 232Th. Activities of 40K, 214Bi (238U daughter), and 208Tl (232Th daughter) were normally distributed with means of 480, 19, and 8 Bq kg−1, respectively. Overall, the activities of all three radionuclides decreased as soil texture became coarser, while distinct geographic areas with elevated levels were probably due to local parent material composition. Natural radionuclide levels were significantly correlated to one another and the average ratio of 214Bi/208Tl/40K in native, unfertilized Saskatchewan surface soils was 1:0.45:26.
Fluidized Bed Material Applied at Disposal Levels: Effects on an Apple Orchard
Authors: Korcak R. F.
Published: July 2010

Atmospheric fluidized‐bed combustion represents an economical technology for the burning of high S fossil fuel. The combustion residue is a dry, alkaline material resulting from the burning of coal (or other fuel source) and limestone. Although the residue has been assessed as a limestone substitute, the current study examines the potential for disposing of relatively large quantities. Fluidized bed material (FBM) was applied at two rates to the surface area within the rows of an established apple (Malus domestica Borkh.) orchard containing four tree types. The rates were either 9.2 kg/m2 (low rate), 36 kg/m2 (high rate), or untreated control. The tree types used were ‘Spuree Rome’ on M9, ‘Redchief Delicious’ on M9 or M9/MM106, and ‘Sturdeespur Delicious’ on M9. Cumulative yields (kg/tree) were enhanced on three of four tree types over a period of 6 yr. A 15% reduction in yield was noted for Redchief Delicious on M9/MM106 stocks at the high FBM rate. No nutritional related problems were noted for this or any other of the tree types used. Part of the yield reduction noted was due to fruit size differences and/or differential sensitivity of this interstock/rootstock combination to the altered soil chemical properties. Generally, amended soil pH increased to about 7.0 for either rate, and electrical conductivity increased five fold at the high rate of FBM addition. Agricultural utilization of large volumes (up to 112 Mg/ha) of FBM, compared to past research where FBM was used as a lime substitute (2–6 mg/ha), appears to be a feasible alternative. However, rootstock selection for apple may need to consider the resultant changes in soil chemical status from FBM additions.
A Possible Mechanism for Manganese Phytotoxicity in Hawaii Soils Amended with a Low‐Manganese Sewage Sludge
Authors: Hue N. V.
Published: July 2010

Knowledge of sludge‐soil interactions is essential for successful utilization of sludges on agricultural lands. To obtain such information, a greenhouse experiment was conducted on three Hawaii soils: a Typic Hydrandept, a Typic Chromustert, and a manganiferous Tropeptic Eutrustox. Each soil received four rates (0, 20, 40, and 80 g kg−1) of a low‐Mn municipal sludge. Lettuce (Lactuca saliva L.) was grown as a test crop. Manganese phytotoxicity unexpectedly occurred in all sludge‐amended treatments of the Oxisol and in the 80 g kg−1 rate of the Vertisol as indicated by reduced dry matter yields and by high plant‐Mn concentrations, which were all greater than 1000 mg Mn kg−1. Soil‐solution Mn also increased, reflecting the problem. In the manganiferous Oxisol, where Mn toxicity was most serious, soil‐solution Mn at transplanting significantly increased from 0.02 to 0.46, 5.57, and 7.26 mg Mn L−1 as sludge rate increased from 0 to 20, 40, and 80 g kg−1, despite a concurrent increase in soil pH from 5.43 to 6.78, 7.91, and 8.10. Four weeks later (at harvest), soluble Mn increased even more drastically from 0.01 in the untreated soil to 57, 640, and 1160 mg Mn L−1 in the 20, 40, and 80 g kg−1 sludge rate, even though soil pH levels of all sludge treatments were essentially equal (pH 5.0). These facts were virtually inexplainable by soil pH, redox conditions or the direct Mn contribution from the sludge. In contrast, Mn complexation by organic ligands (e.g., tartaric, pyruvic, protocatechuic acids), which were found in considerable quantities in the soil solutions of sludge‐amended soils, accounted for 76 to 99% of the soluble Mn, and adequately explained the high and phytotoxic levels of Mn in soil solutions.
Volatilization of Organic Chemicals from Soil as Related to Their Henry's Law Constants
Authors: Spencer W. F. , Cliath M. M. , Jury W. A. , Zhang Lian‐Zhong
Published: July 2010

The output from a pesticide screening model indicated that chemicals with low Henry's Law constants (KH) will tend to accumulate at the soil surface when water is evaporating, resulting in an increased volatilization with time. Volatilization losses and surface distributions of two pesticides with widely differing KH, were measured to test the predictions of the screening model, particularly with respect to the importance of KH in controlling relative volatilization and vapor behavior. Volatilization of prometon (2,4‐bis(isopropylamino)‐6‐methoxy‐s‐triazine], a Category III compound with low KH, increased with time with water evaporating and prometon accumulated at the soil surface. Volatilization of lindane (gamma isomer of 1,2,3,4,5,6‐hexachloro‐cyclohexane), a Category I compound with high KH, decreased with time with or without water evaporating and did not accumulate at the surface with water evaporating. The experimental data confirmed the model predictions that volatilization of chemicals with low KH is controlled by the air‐boundary layer above the soil surface, whereas control of volatilization of Category I chemicals with high KH is within the soil. Accumulation and increased volatilization of compounds with low KH are controlled by boundary layer thickness and water evaporation rate as well as KH. The phenomena of organic chemicals with low KH accumulating at the soil surface following convective movement in evaporating water could greatly enhance their volatilization and increase their availability for photolysis and runoff into surface waters. Sufficient accumulation can occur that changes in adsorption coefficients with concentration must be taken into account in modeling their volatilization.
Radionuclides in Louisiana Soils
Authors: Meriwether John R. , Beck James N. , Keeley Dean F. , Langley M. Pamela , Thompson Ronald H. , Young John C.
Published: July 2010

Concentrations of natural and man‐made radionuclides including 40K, 137Cs, and some of the decay products of 238U and 232Th were determined in soil. Samples were taken at a set of permanent radiation monitoring stations and from random points across the state of Louisiana. The concentrations of the radionuclides were found to be correlated with soil suborder: the lowest values found in the Udults of the northern portion of the state and the highest concentrations found in the Aquepts of the flood plains and the Hemists of the coastal marshes, suggesting that processes such as weathering, transport of solids, and dissolution may be fractionating these elements into soils of water environments. The concentration of K was found to vary from 3180 to 24 900 mg kg−1; U varied from 2.3 to 4.0 mg kg−1; and Th from 8.0 to 24.1 mg kg−1. Cesium‐137, the fission product, was found only in the top 15 to 20 cm of the soils with no statistically significant aerial distribution across Louisiana.
Trickle Irrigation of Cotton with Treated Sewage Effluent
Authors: Papadopoulos I. , Stylianou Y.
Published: July 2010

The objectives of this field study, conducted in 1984 through 1986, were to assess the long‐term effects of applying treated municipal effluent (ECw = 2.6 dS m −1; SAR = 12.0) by trickle irrigation on soil N fertility, soil salinity, and yield of cotton (Gossypium hirsutum L. cv. Sindos 1980) under semiarid conditions. Secondary treated effluent was compared with borehole water. Both waters were supplemented with 0, 30, 60, and 90 mg N L−1. The N concentration in the effluent was about 30 mg L−1 during the 3 yr of experimentation. The residual soil NO3‐N and the NO3‐N concentrations in laminae and petioles were in general greater in the effluent‐irrigated crops. With both waters, excessive salt buildup occurred at the periphery of the wetting front. Sodium adsorption ratio (SAR) was reduced beneath the dripper in the surface 15 and 30 cm depth with borehole water and effluent, respectively, but below this depth the reverse occurred. Under the conditions of soil type, climate, and borehole water and effluent qualities used during this experiment, effluent was generally superior to borehole water, particularly at the lower N levels in increasing yields. The seedcotton yield obtained in the first season was significantly greater in the effluent irrigated treatments supplemented with N up to 60 mg L−1; in 1985 and 1986 seasons, yield with treated effluent was significantly higher in comparison with borehole water when additional N of 30 mg L−1 was applied. It can be concluded that municipal‐treated effluent containing 30 mg N L−1 can be used effectively by trickle irrigation systems as a source of irrigation water and N, and with appropriate N and water management, ecological hazards due to NO3‐N are minimized, and salinity and sodicity are maintained at acceptable levels for cotton.
Elution of Selenium from Contaminated Evaporation Pond Sediments
Authors: Alemi M. H. , Goldhamer D. A. , Grismer M. E. , Nielsen D. R.
Published: July 2010

Selenium‐contaminated sediments were collected from evaporation ponds at the Kesterson National Wildlife Refuse in California. Columns of undisturbed, freeze‐dried, and air‐dried sediments were each leached with deionized water, California aqueduct water, and saline water. Total Se and inorganic Se were measured in the effluent. Following leaching, the sediment cores were sectioned, extracts were prepared using deionized water, and analyzed for total Se, inorganic Se, and selenite using fluorimetric techniques. Selenium remained immobile in the undisturbed sediments, but freeze‐ and air‐drying increased Se mobility. The maximum concentrations of total Se in the effluent from undisturbed, freeze‐dried, and air‐dried sediments were 32, 7600, and 232 650 nmol L−1, respectively. Microbial activity played an important role in the reduction of Se to immobile and volatile forms. Se recovered in the effluent and from water extraction of the sediments following leaching was highest for deionized water and least for aqueduct water under nonsterilized conditions. The composition of solution did not significantly influence the leaching of Se under sterilized conditions. Introducing Se to previously leached sediments resulted in an increase in water‐extractable Se, particularly near the surface. However, when the concentration of added Se was high (31.70 µmol L−1 in this study), the increase in water‐extractable Se also occurred at greater depths in the sediments.
A Case Study of the Effects of Oil Shale Operations on Surface and Groundwater Quality: I. Sources of Contamination and Hydrologic Controls on Water Composition
Authors: Garland T. R. , Wildung R. E. , Zachara J. M.
Published: July 2010

A study was undertaken to determine the effects of the disposal and leaching of retorted shale and other wastes on the water quality of a local drainage at the Rifle Oil Shale Project. An estimated 200 000 t of retorted shale and 146 000 t of raw shale were disposed during a 35‐yr period at the site, located near Anvil Points, CO. Previous studies suggested that operations did not impact the site. However, this investigation revealed elevated salt concentrations in wells, seeps, and surface waters downstream of the site. This investigation included a detailed survey of the potential contaminant and water sources at the site and measurement of inorganic and organic constituents in surface and groundwaters as a function of proximity to the disposal areas and hydrologic factors in the watershed. Sources of the salts were unlined evaporation ponds, subsoils leached by waters from leaking sanitary water system, and leachates from the raw and retorted shale piles, which also serve as artificial water recharge areas. These sources had not been previously detected because prior investigations did not take into account distinct spatial and diurnal fluctuations in flow rate in the surface waters, which alternately diluted and concentrated contaminants contributed by groundwater recharge. Fluctuations in flow rate were shown to result from daily meteorological effects on snowmelt (December–March) and transpiration by vegetation in the watershed (June–December). Detailed assessments of these factors are required before the long‐term effects of an oil shale industry on the Colorado River Basin can be determined.
A Case Study of the Effects of Oil Shale Operations on Surface and Groundwater Quality: II. Major Inorganic Ions
Authors: Garland T. R. , Zachara J. M. , Wildung R. E.
Published: July 2010

The distribution of the major inorganic ions in surface and groundwater, as related to substrata and hydrologic phenomena, was determined in a semiarid watershed representing an important area of oil shale development in northwestern Colorado. Surface and alluvial groundwaters were analyzed with time over a period of 1 yr, both upstream and downstream of an unengineered oil shale disposal site. These observations provided unique insight into the chemical and hydrologic controls on the composition of major ions in ground and surface waters. The primary dissolved species in the surface and groundwaters above and below the disposal site were Na +, Mg2+, Ca2+, SO2−4, and HCO−3. Increases in total salts in alluvial groundwaters below the disposal site were due primarily to Na + and SO2−4. Groundwaters above the disposal site were found to be in near equilibrium with calcite and dolomite; waters below the site were also in equilibrium with gypsum. Concentrations of the other ions measured all increased below the site, but elements lacking major solubility controls in calcareous soil and subsoil, i.e., K++, Li++, CL−, and NO−3, were most elevated. These solutes decreased in concentration down‐gradient from the waste disposal area, but different phenomena controlled their behavior. Concentrations of HCO−3 in alluvial groundwater fluctuated seasonally (+20%), reflecting a combination of biological (microbial and root respiration) and mineral solubility (e.g., CaCO3) controls. Although the primary source of N to groundwater was NH+4‐laden waste water, NO3 − constituted the major N species measured as a result of nitrification in the relatively aerobic groundwater system. Macroions indicative of the influence of the waste disposal site on surface water quality were CL−, K++, and Li++. Lithium could serve as a sensitive indicator of the presence of retorted shale leachate.
Dynamics of Carbon, Nitrogen, and Phosphorus Cycling in a Sawgrass Tidal Marsh with Special Reference to the Aboveground Primary Production
Authors: Hsieh Y. P.
Published: July 2010

The litter‐bag method was used to assess the disappearance rates of organic C, N, and P from the plant detritus of a sawgrass (Cladium jamaicense Crantz) tidal marsh in North Florida. A steady‐state kinetic model was used to simulate the effects of C, N, and P cycling dynamics on the quantity and quality of soil organic matter in the marsh. Four basic parameters were required for the model, namely, (i) net annual primary production of C, N, and P, (ii) soil organic C, N, and P in the biologically active layer, (iii) disappearance rate of dead standing crop, and (iv) disappearance rates of sawgrass C, N, and P from the litter‐bag. The decomposition of sawgrass C, N, and P can be described by a two‐component model through which a labile fraction and a refractory fraction of the primary production are defined. The rate constants of the labile fraction are one to two orders of magnitude greater than those of the refractory fraction. Simulation study indicated that the time required for soil C, N, and P to reach the steady state were 30, 60, and 70 yr, respectively. The simulation also indicated that the C/N ratio of the soil organic matter changed most significantly in the first 10 yr of the marsh development, whereas the N/P ratio remained relatively the same during the same period of time. The C/N and N/P ratios and the mean fraction remaining of soil organic matter all approach their respective steady‐state values, which are 23, 13, and 0.47, respectively. The observed C/N and N/P ratios of the soil organic matter were 21 and 13, respectively. The calculated labile fractions of the sawgrass were 0.34, 0.205, and 0.488 for organic C, N, and P, respectively. The mean retention time of C, N, and P in the labile fraction was 8.5 months. The MRTs of the refractory fractions were 10, 29, and 33 yr for C, N, and P, respectively. The bulk of the soil organic matter consists almost entirely of the refractory fraction of the primary production. According to the simulation, decomposition rate constants of plant detritus were the most significant and sensitive parameters that determine the quantity and quality of the soil organic matter. The annual N and P cycling rates between the aboveground sawgrass and the soil were estimated to be 18.8 g/m2 and 1.9 g/m2, respectively.
Use and Misuse of the DTPA Soil Test
Authors: O'Connor G. A.
Published: July 2010

The DTPA soil test was originally developed to identify near‐neutral and calcareous soils with insufficient available Zn, Fe, Mn, and Cu for maximum yields of crops. It apparently draws on labile pools it was designed to extract and correlates well with plant micronutrient concentrations when the soil metal levels are neither too high nor too low. The soil test reliably reflects metal loadings to soils supplied in a variety of forms, but may not reliably predict plant metal concentrations expected from increased soil loadings. The successes or failures of the soil test noted in the literature can be explained as correct uses or misuses, respectively, of the test. The soil test is best used to identify micronutrient deficient, near‐neutral, and calcareous soils. Whenever one strays from the original design of the test, one should be aware of the possible consequences and pass that awareness on to others.
Groundwater and Soil Leachate Inorganic Nitrogen in a Wisconsin Red Pine Plantation Amended with Paper Industry Sludge
Authors: Bockheim J. G. , Benzel T. C. , Lu Rui‐Lin , Thiel D. A.
Published: July 2010

In late August 1984, a 2.5:1 primary/secondary paper industry sludge was applied to a row‐thinned, 27‐yr‐old red pine (Pinus resinosa Ait.) plantation in central Wisconsin at levels of 32, 63, and 94 dry Mg ha−1 (550, 1120, and 1670 kg N ha−1, respectively). There were positive treatment effects on NO3‐N and NH4‐N in soil leachates and groundwater, but because of sample variability, few of these differences were significant at the p ≤ 0.05 level. Nitrate‐N concentrations exceeded 10 mg L−1 for all treatments at the 10‐, 45‐, and 75‐cm depths, but the potability standard was exceeded at the 165‐cm depth and in groundwater only on plots receiving the medium and heavy applications. Nitrate‐N concentrations generally were greater in the upper 30 cm of the saturated zone than at 60 and 90 cm, suggesting a lack of vertical mixing. Whereas the maximum NO3‐N concentration decreased with depth, the time required for NO3‐N concentrations to exceed 10 mg L−1 for a given treatment and the duration of the period when NO3‐N concentrations exceeded 10 mg L−1 increased with depth. The seasonal trends in inorganic N concentrations in soil water collected at the 10‐ and 45‐cm depths could be explained on the basis of N mineralization as derived from field incubation studies. A regression equation relating maximum NO3‐N in groundwater to N content of the applied sludge indicates that little groundwater degradation will occur at depths of ≥ 5.2 m in central Wisconsin when the N application to pole‐sized red pine is ≤800 kg ha−1 (≤46 dry Mg sludge ha−1).
2,3,7,8‐Tetrachlorodibenzo‐P‐dioxin: Aspects of Its Important Properties and Its Potential Biodegradation in Soils
Authors: Arthur Mickey F. , Frea James I.
Published: July 2010

2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is a persistent xenobiotic compound that has become widely dispersed in the environment. In laboratory animals, TCDD is acutely and chronically toxic, and is a carcinogen, mutagen, and teratogen. In humans, epidemiological studies of residents from Times Beach, MO, and Seveso, Italy, have failed to document significant TCDD‐induced health effects. The environmental persistence of TCDD is due in part to its resistance to microbial attack. The factors responsible for microbial recalcitrance of pesticides are reviewed and related to the recalcitrance of TCDD. It is suggested that a major factor limiting TCDD degradation in the environment is its unavailability to the indigenous microflora. The possibility to decontaminate soils by mobilizing TCDD for attack by soil microorganisms is discussed.
Denitrification below the Crop Rooting Zone as Influenced by Surface Tillage
Authors: Parkin T. B. , Meisinger J. J.
Published: July 2010

In recent years, there has been increased concern over pollution of groundwater by NO3−, yet little is known about microbial N transformations below the crop rooting zone. This study investigated the importance of microbial denitrification below the crop rooting zone of conventional and no‐till corn plots. The soil was a well‐drained Matapeake silt loam located in the Atlantic Coastal Plain. Plots were sampled in 30‐ and 60‐cm depth increments down to the water table, which occurred at ca. 420 cm. Total viable bacteria and numbers of denitrifying bacteria decreased exponentially with increasing soil depth down to 150 cm. From 180 cm to the top of the water table total bacterial numbers were very low (< 100 organisms/gram). No CO2 production activity was observed below the 180‐cm depth in unamended soil incubated aerobically at 25°C for 24 h. Anaerobic incubations with added NO3− and glucose showed no denitrifying activity below the 180‐cm depth. These results indicate that C levels below the rooting zone in this well‐drained, low organic matter soil are too low to support anaerobic conditions necessary for denitrification or to sustain a microbial population. Therefore, denitrification is not a mechanism of significant NO3− loss below the crop rooting zone at this location. Surface tillage practices had little influence on microbial activity below the root‐zone.
Preferential Movement of Oxygen‐18‐Labeled Water and Nitrogen‐15‐Labeled Urea through Macropores in a Nicollet Soil
Authors: Priebe D. L. , Blackmer A. M.
Published: July 2010

Studies were conducted to evaluate the possibility that preferential movement of water through soil macropores was an important factor in previously observed losses of surface‐applied urea and nitrate from Iowa soils. Granules of 15N‐labeled urea were applied to the surfaces of undisturbed soil columns at their water‐holding capacities, and then 18O‐labeled water was applied to simulate a 25‐mm rainfall event. Effluent from the bottoms of the columns was incrementally collected and analyzed. Soil from the columns was removed in layers 24 h after initiation of the rainfall, and each layer was analyzed to determine depths of movement of labeled water and N. Significant amounts of labeled water and urea were present in the first increment of effluent from some columns. Labeled water and urea moved much deeper and were more dispersed in all soil columns than would be expected in absence of preferential movement of water through macropores. The results suggest that preferential movement of water through macropores is more important as a factor affecting the movement and fate of nitrogen in Iowa soils than generally has been recognized. A better understanding of where and when this preferential movement occurs and how it influences leaching of N and other solutes in soils is needed to advance efforts to identify management practices that reduce losses of N and other chemicals from agricultural soils to the environment.
Picloram Movement in Soil Solution and Streamflow from a Coastal Plain Forest
Authors: Michael J. L. , Neary D. G. , Wells M. J. M.
Published: July 2010

Picloram (4‐amino‐3,5,6‐trichloropicolinic acid) was aerially applied to a longleaf pine (Pinus palustris L.) site in the upper coastal plain of Alabama to control kudzu [Pueraria lobata (Willd.) Ohwi]. Pellets (10% a.i.) were spread at the rate of 56 kg ha−1 on loamy sand Typic Kanhapludult soils. Movement of this herbicide was monitored with mineral soil samples, tension‐cup lysimeters, flow‐proportional streamflow samplers, and discrete samplers. Picloram levels in the upper 15 cm of mineral soil peaked at 0.96 to 2.25 mg kg1 25 d after application, depending on slope position, and declined to 0.13 to 0.29 mg kg1 1 yr later. In soil solution, picloram was detected at a depth of 0.4 m between 26 and 273 d after application. Only 4 of 15 lysimeters consistently contained detectable residues. Maximum picloram levels in soil solution were 130, 450, and 191 mg m−3 for ridge, midslope, and toe‐slope positions, respectively. Downstream monitoring began 4 d after the herbicide application, and an initial concentration of 68 mg m−3 of picloram was detected. The maximum downstream concentration of 77 mg m3 occurred 18 d after the application, immediately after the second storm event. Downstream levels dropped to <10 mg m3 after 90 d and to <2 mg m−3 after 200 d. Following localized retreatment along the stream more than a year after the initial treatment, levels climbed again into the 20 to 30 mg m3 range. Most of the initial off‐site movement came from a perennial stream that had been inadvertently treated, but subsequently storm runoff was the largest contributor to stream contamination. Picloram residues in this stream were similar to those observed downstream, but they were higher (up to 241 mg m3 and dropped faster to below 2 mg m3 after D 150.
Productivity of Clay Tailings from Phosphate Mining: I. Biomass Crops
Authors: Mislevy P. , Blue W. G. , Roessler C. E.
Published: July 2010

Phosphate mining in Florida yields waste products of phosphatic clay and quartz sand tailings, each making up about one‐third of the original matrix (PO4 ore, sand, and clay). Phosphatic clay ponds typically occupy about 50% of the mined sites and normally require 10 to 15 yr before 40 to 50% solids are obtained. These clays contain no phytotoxic materials and are high in most plant nutrients. When surface water has disappeared, these clays are classified as clayey Haplaquents. A split‐plot field experiment was conducted to study biomass yield, quality, plant nutrient concentrations, changes in soil nutrients, and 226Ra. Seven biomass crops—(i) elephantgrass (Pennisetum purpureum L. ‘PI 300086’), (ii) leucaena [Leucaena leucocephala (Lam.) De Wet], (iii) alemangrass [Echinochloa polystachya (H.B.K) Hitche], (iv) erianthus [Erianthus arundinaceum (Retz) Jesw ‘IK 76‐63’], (v) desmodium (Desmodium cinerascens A. Gray), (vi) sweet sorghum [Sorghum bicolor (L.) Moench ‘USDA M 8IE’], and (vii) forage sorghum] Sorghum bicolor (L.) Moench ‘Pioneer 931’]—were grown on the phosphatic clay with and without a 5‐cm surface layer of quartz sand tailings. Nitrogen was the only fertilizer element applied for grass species and no fertilizer was applied for legumes during the 4‐yr period. Dry biomass yield averaged over 4 yr for erianthus, leucaena, and elephantgrass averaged 139.6, 58.5, and 56.5 Mg ha−1 yr−1, respectively. Crude protein and digestibility were low in mature, whole‐plant samples except for leucaena (122.0 g kg−1). Generally, all whole plants contained adequate concentrations of nutrients averaging (g kg−1) P, 2.05; K, 11.5; Ca, 4.3; Mg, 2.77 and (mg kg−1) Cu, 4.0; Zn, 26; Fe, 68; and Mn, 35. Mehlich‐I‐extractable soil nutrient concentrations changed little over the 4‐yr period. Radium‐226 concentration in plant tissue (0.23 pCi g−1) was nearly six times higher than the concentration measured in plants from an unmined surface Spodosol (0.04 pCi g−1). Data indicate that these present‐day waste lands can be a valuable resource for biomass production.
Acid Rain and Seed Yield Reductions in Corn
Authors: Craker Lyle E. , Waldron Peter F.
Published: July 2010

Seed yields were significantly reduced on corn (Zea mays L.) plants where the silks had been exposed to an episode of simulated acid rain at pH 3.6 as compared with yields on plants with silks exposed to simulated rain of pH 5.6. The reduction in yield appeared related to a decrease in pollen germination and tube elongation associated with acidic conditions and limited quantities of pollen available for pollination. Germination and tube elongation of pollen were inhibited when grown on an agar medium acidified to pH 4.6 with simulated rain. Germination of pollen grains was reduced as much as 75% on silks previously exposed to a simulated rain of pH 3.6 as compared with germination on silks exposed to simulated rain of pH 5.6. The results suggest that under environmental conditions that limit the quantity of pollen, acid rain could reduce crop yields in corn by inhibiting the reproductive process.
Fate and Transport of Biological and Inorganic Contaminants from On‐Site Disposal of Domestic Wastewater
Authors: Reneau R.B. , Hagedorn C. , Degen M.J.
Published: July 2010

An on‐site wastewater disposal system (OSWDS) is the primary method for domestic waste disposal in sparsely populated areas and in numerous suburban counties. The most common OSWDS is a septic tank with a subsurface soil absorption system that relies on gravity to move wastewater from the residence to the soil with minimal pretreatment of waste before application to the soil. Much of the renovation occurs as the wastewater percolates through the soil prior to reaching ground or surface waters. In 1980, 20.9 million residences (24.1% of the total in the USA) applied approximately 14 × 109 L of domestic wastewater to U.S. soils each day. These numbers emphasize the need for assessing the effect of OSWDS on the quality of the environment. This review addresses the potential impact of selected biological and chemical contaminants present in domestic wastewater on environmental quality. Inefficient use of a soil's renovative capacity (primarily because of poor effluent distribution) can result in extensive travel distances for biological or chemical contaminants as well as hydraulic failure of the OSWDS. The need for further investigation of the potential for water contamination from nitrogenous components and possible mechanisms to reduce the degradation potential of N is addressed. Most studies assume that the dynamics of viral translocation through soil resemble those of fecal bacteria. This assumption may not be correct. Lastly, a critical examination of fate of N, viruses, and fecal bacteria introduced into soils via alternative OSWDS and modified conventional OSWDS should be a priority research initiative.
Application of Sewage Sludge and Other Amendments to Coal Refuse Material: II. Effects on Revegetation
Authors: Pietz R. I. , Carlson C. R. , Peterson J. R. , Zenz D. R. , Lue‐Hing C.
Published: July 2010

The effects of sewage sludge, lime, and gypsum on the revegetation of acidic coal refuse material were studied at a Fulton County, IL, land reclamation site. Treatments consisted of a control, 542 dry Mg ha−1 anaerobically digested sewage sludge, 89.6 Mg ha−1 lime, 112 Mg ha−1 gypsum, and combinations of these amendments. The experimental plots were seeded with a mixture of bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea L.), and alfalfa (Medicago sativa L.). Yearly analysis of coal refuse material (0–15 cm) showed that the concentrations of NH+4‐N, [NO−3 + NO−2]‐N, available P, and water‐soluble K were the highest in sludge‐amended treatments, but they decreased with time. Plant yields increased each year from 1978 to 1980 in treatments receiving lime, sewage sludge, or both amendments. The highest yield of 6.00 Mg ha−1 occurred in the 1980 sludge + lime treatment. In 1980, the order of dry matter plant yields by treatments was sewage sludge + lime > gypsum + sewage sludge + lime > lime > sewage sludge > gypsum + sewage sludge > gypsum + lime > gypsum = control. Coal refuse and tissue K levels indicated that supplemental K would be desirable for long‐term maintenance of a vegetative cover. The better survival of bromegrass and tall fescue, as compared to alfalfa, reflected the coal refuse pH and the shorter root system of the more acid‐tolerant grasses. Concentrations of Al, Fe, Pb, and Zn in composite plant samples from some treatments exceeded the phytotoxic limits for these metals in plants. Potential plant toxicity from metals in the coal refuse material was most likely reduced by reactions with the applied sewage sludge and lime.
First‐Year Nutrient Availability from Injected Dairy Manure
Authors: Motavalli P. P. , Kelling K. A. , Converse J. C.
Published: July 2010

Estimates of N, P, and K availability to corn (Zea mays L.) from injected dairy manure on three field sites in south central Wisconsin were made using a fertilizer equivalence approach. Nutrient uptake from treatments of a control, three rates of manure (approx. 53, 97, and 138 Mg ha−1 yr−1 on a wet basis), and three rates of broadcast fertilizer were evaluated. Crop nutrient recoveries of fertilizer N, P, and K were generally higher than crop recoveries of manure total N, P, and K. Estimates of first year N, P, and K availability showed substantial variability across rate, location, and year with standard deviations often about 50% of the mean. Ranges for N, P, or K availability were 12 to 63, 12 to 89, and 24 to 153%, respectively. These data do not identify those factors responsible for differences in nutrient availability from one site‐year to another. Biological or chemical availability indices of a 1‐wk anaerobic incubation at 40 °C or a 16‐h autoclaving in 0.01 M CaCl2 solution were evaluated as measures of N availability and compared with field results. Correlations between measured changes in NH4‐N from these indices, as well as total Kjeldahl N and inorganic N levels in the top 30 cm of soil 4 to 6 wk after treatment application, and N uptake indicated inorganic N levels to be a better index of N availability than the other indices examined. However, to determine nutrient availability on a routine basis, more reliable biological or chemical indices are necessary. A simple model may help to simulate environmental effects and the contribution of residual nutrients in the soil.