Boron (B) sorption and desorption reactions in 10 soil samples from New Mexico were investigated. seven of the soils conformed to Langmuir adsorption isotherm, but only over limited concentration ranges. On other hand, Freundlich isotherm was applicable entire B range (0 100 µg/ml) for all soils. Simple multiple regression models allowed various parameters be predicted selected properties. For example, a equation including Fe2O3%, organic carbon (OC) %, specific surface 98% variance K...

Abstract Comparisons are made between observed and calculated effluent concentration distributions for the movement of 2,4,5‐T (2,4,5‐trichlorophenoxyacetic acid) through 30‐cm long unsaturated soil columns. The comparisons using both analytical numerical solutions a previously published model, which included effects intra‐aggregate diffusion adsorption. results in this study indicate that adsorption/desorption main mechanisms responsible tailing. An estimated 60% Was found to occur stagnant...

Laboratory and greenhouse studies compared the ability of water treatment residuals (WTRs) to alter P solubility leaching in Immokalee sandy soil (sandy, siliceous, hyperthermic Arenic Alaquod) amended with biosolids triple superphosphate (TSP). Aluminum sulfate (Al-WTR) ferric (Fe-WTR) coagulation residuals, a lime softening residual (Ca-WTR) produced during hardness removal, pure hematite were examined. In equilibration studies, reduce soluble followed order Al-WTR > Ca-WTR = Fe-WTR >>...

Increasing emphasis on phosphorus (P)-based nutrient management underscores the need to understand P behavior in soils amended with biosolids and manures. Laboratory greenhouse column studies characterized forms leachability of eight products, chicken manure (CM), commercial fertilizer (triple superphosphate, TSP). Bahiagrass (Paspalum notatum Flugge) was grown for 4 mo two acid, P-deficient Florida sands, representing both moderate (Candler series: hyperthermic, uncoated Typic...

ABSTRACT Efficient utilization of biosolids P for agronomic purposes requires accounting differences in the phytoavailability various biosolids. Greenhouse studies were conducted with a common pasture grass grown two P‐deficient soils amended 12 and commercial fertilizer (triple superphosphate, TSP) to quantify uptake assess relative phytoavailabilities sources. Biosolids grouped into three general categories TSP: high (>75% TSP), moderate (25–75% low (<25% TSP). Two biosolids,...

Abstract The DTPA soil test was originally developed to identify near‐neutral and calcareous soils with insufficient available Zn, Fe, Mn, Cu for maximum yields of crops. It apparently draws on labile pools it designed extract correlates well plant micronutrient concentrations when the metal levels are neither too high nor low. reliably reflects loadings supplied in a variety forms, but may not predict expected from increased loadings. successes or failures noted literature can be explained...

Abstract The effect of soil solution composition on Zn sorption was investigated in nine soils varying physical and chemical properties. Most applied 0.01 N CaCl 2 strongly sorbed by the desorption negligible even after five cycles. At initial concentrations ⩽ 10 ppm, could be described Freundlich isotherm equation. Deviations from this equation were observed at higher concentrations, suggesting presence more than one type site or mechanism for soils. effects anion species (Cl ‐ , NO 3 SO 2‐...

Man has land-applied societal nonhazardous wastes for centuries as a means of disposal and to improve the soil via recycling nutrients addition organic matter. Nonhazardous include vast array materials, including manures, biosolids, composts, wastewater effluents, food-processing wastes, industrial by-products; these are collectively referred herein residuals. Because economic restraints environmental concerns about land-filling incineration, interest in land application continues grow. A...

Abstract Methods for characterizing adsorption‐desorption of 2,4,5‐T (2,4,5‐trichlorophenoxyacetic acid) in the soil were investigated. Using conventional method, adsorption isotherms conformed to linearized Freundlich equation initial concentrations 2 176 µmol/liter. Desorption from soils exhibited significant hysteresis at all concentrations, with lower showing greater hysteresis. The longer equilibration time desorption, was observed Therefore, nonattainment equilibrium not evident as a...

Abstract The importance of diffusion in moving Fe to plant roots was estimated by theoretical calculations. In studies chelates increased the and uptake increasing concentration gradient diffusible sorghum ( Sorghum vulgare ). Uptake linearly with solution. Self‐diffusion coefficients were determined both aqueous media soil. media, 6.2 × 10 ‐6 cm 2 sec ‐1 for Fe, 5.4 FeEDDHA, 4.2 FeDTPA, 3.9 FeEDTA. soil, a correction factor used adjust apparent porous system self‐diffusion coefficients....

Runoff losses of dissolved and particulate phosphorus (P) may occur when rainfall interacts with manures biosolids spread on the soil surface. This study compared P levels in runoff from soils amended several sources, including 10 different dairy manure (untreated treated Fe or Al salts). Simulated (71 mm h(-1)) was applied until 30 min collected boxes (100 x 20 5 cm) to which sources were surfaced applied. Materials achieve a common plant available nitrogen (PAN) rate 134 kg PAN ha(-1),...

Abstract Cadmium sorption‐desorption by three Ca‐saturated, calcareous soils was studied in the presence of various Ca salts. retention extensive all soil‐solution systems and best characterized a two‐part Freundlich relationship. Part I isotherm interpreted to represent Cd highly Cd‐specific adsorption sites, while part II represented mixture nonspecific sites. This interpretation supported desorption data. Differences sorption from solutions were at least partially rationalized considering...

Increasing emphasis on phosphorus (P)-based nutrient management underscores the need to understand P behavior in soils amended with biosolids and manures. Laboratory greenhouse column studies characterized forms leachability of eight products, chicken manure (CM), commercial fertilizer (triple superphosphate, TSP). Bahiagrass (Paspalum notatum Flugge) was grown for 4 mo two acid, P-deficient Florida sands, representing both moderate (Candler series: hyperthermic, uncoated Typic...

Phosphorus‐based nutrient management will inevitably be required for land application of biosolids. Water‐extractable phosphorus (WEP) in livestock manures is an indicator loss from agricultural watersheds and this study evaluated its use The WEP to total percentage (PWEP) 41 biosolids (representing a variety wastewater solids treatment processes) was compared dairy poultry triple superphosphate fertilizer. mean PWEP conventionally treated stabilized 2.4%, which significantly lower than...

Land application of drinking‐water treatment residuals (WTR) has been shown to control excess soil soluble P and can reduce off‐site losses surface ground water. To our knowledge, no field study directly evaluated the impacts land WTRs on water quality. We monitored effects three organic sources (poultry manure, Boca Raton biosolids, Pompano biosolids) or triple superphosphate co‐applied with an aluminum‐based WTR (Al‐WTR) Al concentrations under natural conditions for 20 mo in a limited...

Abstract The dissolution rate of gypsum fragments in aqueous solutions was studied for Ca‐soil‐gypsum mixtures at two contents and four soil water velocities. Equations were derived to estimate the coefficient different velocities a given surface area gypsum. velocity controls both time which an elemental volume is moving soil‐gypsum layer coefficient. Increasing increased but decreased contact between unit fragments; net effect that increasing decreases rate. on much greater higher range...

Long-term depositions of animal manures affect P dynamics in soils and can pose environmental risks associated with losses. Laboratory studies were done on solubility characteristics a manure-impacted Immokalee soil (sandy, siliceous, hyperthermic Arenic Alaquod) the effectiveness water treatment residual (WTR) controlling leaching. Soil samples contrasting initial total concentrations prepared by mixing surface A horizon minimally P-impacted E horizon. Effects various ratios horizons, WTR...

Abstract Sorption/desorption isotherms were used to evaluate the effects of solution composition on retention nickel (Ni) by soils varying physical and chemical properties. Soils examined included agricultural New Mexico, as well from potential waste disposal sites. Sorption Ni 0.01 N CaCl 2 was extensive for all samples: more than 99% added sorbed in some cases. Desorption slight (extreme hysteresis). Ability extract with diethlyenetriaminetetraacetate (DPTA), however, indicated that...