Implications of chloride-enhanced cadmium uptake in saline agriculture: modeling cadmium uptake by maize and tobacco. (2012). Int J Environ Sci Technol, 9:69-77 (original) (raw)
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International Journal of Environmental Science and Technology, 2011
Chloride salinity has been strongly related to enhanced cadmium (Cd) uptake by plants due to increased solubility in the soil solution, even in agricultural soil with very low levels of cadmium. This finding is relevant because the cadmium content of food crops is an important concern for human health. Therefore, the aim of this study was to predict and discuss the chlorine-enhanced uptake of cadmium by two common crops: maize and tobacco under ''non-saline'' (1 mM) and ''very strongly saline'' (200 mM) scenarios using a modified 'biotic ligand model' and datasets from a set of soil and hydroponic experiments. Results indicated that predicted cadmium uptake rates (expressed as cadmium in plant lmol m-2 root) by maize and tobacco plants were consistently higher (54 and 15%, respectively) assuming conditions of 'very strong salinity' soil compared to the simulated 'non-saline' soil. In the light of the results of the present research, valuable information is given on modeled cadmium phytoavailability as an indication of the potential risk due to increased cadmium uptake by crops under saline conditions, especially as the enhancement of cadmium uptake in the presence of Clsalinity may be a general trend that occurs in many edible crops. The biotic ligand model parameterization applied in the present study attempted to simulate conditions commonly found in natural cadmium and salt-affected soils. However, caution is needed to extrapolate results obtained from these models to real soil conditions.
Chloride salinity has been strongly related to enhanced cadmium (Cd) uptake by plants due to increased solubility in the soil solution, even in agricultural soil with very low levels of cadmium. This finding is relevant because the cadmium content of food crops is an important concern for human health. Therefore, the aim of this study was to predict and discuss the chlorine-enhanced uptake of cadmium by two common crops: maize and tobacco under ''non-saline'' (1 mM) and ''very strongly saline'' (200 mM) scenarios using a modified 'biotic ligand model' and datasets from a set of soil and hydroponic experiments. Results indicated that predicted cadmium uptake rates (expressed as cadmium in plant lmol m -2 root) by maize and tobacco plants were consistently higher (54 and 15%, respectively) assuming conditions of 'very strong salinity' soil compared to the simulated 'non-saline' soil. In the light of the results of the present research, valuable information is given on modeled cadmium phytoavailability as an indication of the potential risk due to increased cadmium uptake by crops under saline conditions, especially as the enhancement of cadmium uptake in the presence of Clsalinity may be a general trend that occurs in many edible crops. The biotic ligand model parameterization applied in the present study attempted to simulate conditions commonly found in natural cadmium and salt-affected soils. However, caution is needed to extrapolate results obtained from these models to real soil conditions.
Modeling the Plant Uptake of Cadmium and Zinc from Soils Treated with Sewage Sludge1
Soil Science Society of America Journal, 1986
To evaluate models for predicting plant uptake of Zn and Cd, a growth chamber study was conducted with soils collected from research plots in Ohio, Indiana, Michigan, and Wisconsin that had been treated 4 yr previously with 100 Mg ha~' of an anaerobically digested sewage sludge from Chicago, IL. The single application of sludge supplied 19-kg Cd and 340 kg Zn ha" 1. Sludge application increased the concentration of Cd and Zn in the shoots and roots of corn (Zea mays L.) seedlings grown for 16 and 22 d in the four soils. The application of sludge had no effect on the growth and properties of the corn root systems. Soil characteristics and kinetic parameters for Zn and Cd uptake were combined with a nutrient uptake model to predict Cd and Zn uptake by corn seedlings. In the untreated and sludge-treated soils predicted Cd uptake (Y) was related to observed uptake (X) in nmol pot~' by: Y = 90.03 + 1.41A"(r = 0.81). Overprediction of Cd uptake by 41% may have resulted from an incorrect value of the Michaelis-Menten constant, K m , and/or neglecting Cd efflux from roots. Calculated Zn uptake in the untreated and sludge-treated soils was related to observed uptake by: Y = 3.29 + 0.857X (r = 0.91) where units for Y and X are nmol Zn pot~'. A sensitivity analysis was conducted with the model to determine how each soil and plant factor affected predicted Cd and Zn uptake. Plant factors that had the greatest effect on Cd and Zn uptake include the root growth constants, average root radius, and water influx rate. Kinetics of Cd and Zn uptake and half-distance between roots had little effect on Cd and Zn uptake. Concentration of Cd and Zn in the soil solution (C,) was the soil parameter showing the greatest effect on predicted metal uptake. In comparison, average buffer power and diffusion coefficients for Zn and Cd had minimal impact on predicted metal uptake.
A Regional-Scale Study on the Crop Uptake of Cadmium from Sandy Soils
Journal of Environmental Quality, 2005
The uptake of Cd and its distribution in crops differs among species and among cultivars within a species. Plant uptake is one of the major pathways by which cadmium (Cd) Petterson (1977), for example, observed that the Cd in soils enters the human food chain. This study was conducted to content of plants grown in solution culture increased in investigate the uptake of Cd by crops from soils within the wastewater irrigation area (WIA) of Braunschweig (Germany) and to develop a the order: oats, wheat Ͻ bean, pea, sunflower, cucumsimple process-oriented model that is suited to predict Cd uptake at ber Ͻ corn, mustard Ͻ radish, kale, rape Ͻ tomato, carthe regional scale. The sandy soils within the WIA (4300 ha) have rot, sorre Ͻ lettuce. Variation of Cd uptake patterns received considerable loads of heavy metals by irrigation using municiamong cultivars within a species has been reported in pal wastewater for up to 40 years. In 1998 and 1999, we sampled soil potato (McLaughlin et al., 1994b), wheat (Chaudri et and plant material at 40 potato (Solanum tuberosum L.), 40 sugar al., 2001; Oliver et al., 1995), durum wheat (Tahvonen beet (Beta vulgaris L.), and 32 winter wheat (Triticum aestivum L.) and Kumpulainen, 1993), maize (Florijn and van Beusifields. In both years and for all three crops, we found close linear chem, 1993), and oat, carrots, and spinach (He and relationships between the Cd content of plant material and the Cd Singh, 1994). concentration in soil solution. For all three crops, we observed a trend Cadmium is transported from soil to plant roots by of relatively increased Cd uptake in the year with the higher saturation deficit of the atmosphere. We interpret this to indicate that transpira-mass flow, diffusion, and interception. Mass flow and tion plays an important role in the Cd uptake of crops under the diffusion are considered to be the most important supply conditions of the WIA. In modeling the uptake of Cd by crops, we mechanism for ions in soil (Marschner, 1995). Mass flow assume that uptake is proportional to mass flow, that is, the product means that ions dissolved in soil solution are transported of water transpired, Cd concentration in soil solution, and a plantto the roots with the transpiration flux. If the uptake specific empirical parameter. The simulations agreed well with the by roots is greater than the supply by mass flow, the observed Cd contents in crops. Our model explained between 66 and ion concentration will decrease at the root surface and 87% of the observed variance. University of Hohenheim, Institute of Soil Science and Land Evalua-for example, those given in Dalton et al. (1975) or Nobel tion, Biogeophysics Section, D-70593 Stuttgart, Germany. This work (1999). In the Barber-Cushman model, solute uptake was funded by the German Research Foundation (DFG). Received 18 by roots is an exclusively active process, whereby in the June 2004. Technical Reports. *Corresponding author (jingwer@unitwo citations mentioned above the solute flux across a hohenheim.de).
Mathematical Model to Simulate the Transfer of Heavy Metals from Soil to Plant
Sustainability, 2021
Heavy metals are naturally occurring elements, but their various applications have led to their wide circulation in the environment, raising concerns over their latent effects on the environment and human health. Their toxicity depends on numerous factors, including chemical species, concentration of heavy metal ions, environmental factors, etc. Experimental studies on the single or cumulative effects of heavy metals on plants are complex, time consuming and difficult to conduct. An alternative is mathematical modeling, which can include different factors into an integrated system and can predict plant and environmental behavior under multiple stressors. This paper presents a mathematical model that simulates the dependence of temperature, concentration of Zn in the soil and the subsequent bioaccumulation in lettuce (Lactuca sativa L.); respectively, the reaction of lettuce to Zn contamination. The main results consist of three mathematical models, based on systems of ordinary diffe...
International Journal of Environmental Research, 2016
This study was carried out as a factorial experiment with 5 levels of cadmium (Cd) (o, 25, 50, 75, and 100 mg/kg), 5 levels of salinity (Control, 4, 5, 6, and 7 dS/m), and two soil textures (sandy loam and clay loam). The results showed that the amount of Cd in root and shoot of sunflower increased as soil salinity and Cd concentration increased. The best concentrations for Cd phytoremediation were 75 mg/kg in sandy loam and 100 mg/kg in clay loam. Mass-Hoffman model in simulating transpiration Cd stress as well as Homaee model in simulating salt stress indicated the best results in light soils. By multiplying the salinity stress model by Cd stress model, the simultaneous model for each soil was calculated. These models in light soil (r2=0.68) and heavy soil (r2=0.81) were compatible with measured values. In the heavy soil, absorbed Cd by plant along with increased salinity reflected low changes, but changes in Cd absorbed by plants in the heavy soil were more uniform than in the li...
Deriving Soil Critical Limits for Cu, Zn, Cd, and Pb: A Method Based on Free Ion Concentrations
Environmental Science & Technology, 2004
We present a method to calculate critical limits of cationic heavy metals accounting for variations in soil chemistry. We assume the free metal ion concentration (M free) to be the most appropriate indicator of toxicity, combined with a protective effect of soil cations (e.g., H + , Ca 2+). Because soil metal cations tend to covary with pH, the concentration of M free exerting a given level of toxic effect (M free,toxic) can be expressed as a function of pH alone. We use linear regression equations to derive M free,toxic in toxicity experiments from soil pH, organic matter content, and endpoint soil metal. Chronic toxicity data from the literature, for plants, invertebrates, microbial processes, and fungi are interpreted in terms of an average log M free,toxic together with distributions of species sensitivity. This leads to critical limit functions to protect 95% of species, of the form log M free,CRIT) RpH + γ. Appreciable effects of soil pH upon log M free,CRIT are found, with R)-1.21 (Cu),-0.34 (Zn),-0.43 (Cd), and-0.83 (Pb). Critical limit functions in terms of the geochemically active soil metal (M soil,CRIT), that pool of metal which controls the free ion concentration, have also been derived, with soil pH and organic matter content as variables. The pH effect on M soil,CRIT is relatively small, with slopes of 0.05 (Cu), 0.19 (Zn), 0.16 (Cd), and 0.20 (Pb), since the effect of pH on M free,CRIT is countered by the variation of M free with pH.
PLoS ONE, 2012
The water budget of soil, the uptake in plants and the leaching to groundwater of cadmium (Cd) and lead (Pb) were simulated simultaneously using a physiological plant uptake model and a tipping buckets water and solute transport model for soil. Simulations were compared to results from a ten-year experimental field study, where four organic amendments were applied every second year. Predicted concentrations slightly decreased (Cd) or stagnated (Pb) in control soils, but increased in amended soils by about 10% (Cd) and 6% to 18% (Pb). Estimated plant uptake was lower in amended plots, due to an increase of K d (dry soil to water partition coefficient). Predicted concentrations in plants were close to measured levels in plant residues (straw), but higher than measured concentrations in grains. Initially, Pb was mainly predicted to deposit from air into plants (82% in 1998); the next years, uptake from soil became dominating (30% from air in 2006), because of decreasing levels in air. For Cd, predicted uptake from air into plants was negligible (1-5%). Citation: Legind CN, Rein A, Serre J, Brochier V, Haudin C-S, et al. (2012) Simultaneous Simulations of Uptake in Plants and Leaching to Groundwater of Cadmium and Lead for Arable Land Amended with Compost or Farmyard Manure. PLoS ONE 7(10): e47002.