A comparison of three soil tests for assessing Cd accumulation in wheat grain

Soil Research ◽  
1999 ◽  
Vol 37 (6) ◽  
pp. 1123 ◽  
Author(s):  
D. P. Oliver ◽  
K. G. Tiller (dec.) ◽  
A. M. Alston ◽  
G. D. Cozens ◽  
R. Naidu

Three extractants, namely ethylenediamine tetraacetic acid (EDTA), CaCl2, and Ca(NO3)2, were compared to assess the relationship between the amounts of cadmium (Cd) extracted from soil and the Cd concentration of wheat grain, with the view to using a soil test for predicting Cd concentrations in grain. The soils used came from 1 glasshouse experiment and 31 field sites sampled over 2 years, and they had received Cd only from historical applications of phosphatic fertilisers. The soils ranged from a heavy clay with a comparatively high carbon content to a sandy soil. The pH values ranged from 4.5 to 7.8. The relationship between Cd concentration in grain and CaCl2- and Ca(NO3)2-extractable soil Cd was variable and for most cases r2 value was <0.6. The use of pH alone to predict Cd concentration in wheat grain was significant (P < 0.05) for all soils used in the glasshouse except the soil with the highest clay content (Inman Valley). In the field experiments, the relationships between Cd concentration in grain and soil pH were significant (P < 0.05) but the r2 values were low, ranging from 0.28 to 0.66. The inclusion of pH and extractable soil Cd (CaCl2- and Ca(NO3)2-extractable) to determine Cd concentration in grain only improved the relationship in one half of the cases in this study. This suggests that there may be little to be gained in prediction of Cd concentration in grain from the use of extractants compared with using soil pH. Soil pH is also an easier, cheaper, and quicker measurement than an extractable soil Cd measurement, particularly in soils with low Cd concentrations where the extraction procedure involves a concentration step. In all cases, grain Cd concentration and EDTA-extractable soil Cd were poorly correlated.

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 448
Author(s):  
Mahrous Awad ◽  
Zhongzhen Liu ◽  
Milan Skalicky ◽  
Eldessoky S. Dessoky ◽  
Marian Brestic ◽  
...  

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.


1968 ◽  
Vol 71 (1) ◽  
pp. 95-104 ◽  
Author(s):  
O. Talibudeen ◽  
S. K. Dey

SummaryThirty-four soils from the Rothamsted Experiments were exhaustively cropped with ryegrass in the glasshouse. The concentration and yield of potassium in ryegrass tops and the potassium intensity in the soil were measured every 4 weeks, after harvesting the grass.The change in K-intensity of soils, rich in potassium, with exhaustion differed from that of ‘poor’ soils. This change was related to the rate of change of the cumulative K-yield. The rate of change of soil K-intensity demarcated periods of intense and limited exhaustion and partial recovery of the soil during cropping.The cumulative K-yield of ryegrass was very significantly related to the K-intensity of the uncropped soil; the ‘16-week’ yield was slightly better related than the ‘60-week’ yield. For Park Grass soils, the relationship was improved by allowing for variations in soil pH.The K-intensity of all soils, with or without manuring, decreased to nearly 10-3 (M)½ in (AR)0 units after 16 weeks cropping, although large differences in K-yield persisted until much later.K-buffer capacity per unit clay content of the soil, measured by a laboratory method, was inversely related to the K-intensity of the uncropped soil. The K-buffer capacities of soils rich in potassium, measured in laboratory and glasshouse experiments, were significantly related, but were unrelated for ‘poor’ soils. The K-buffer capacity (laboratory method) of Rothamsted soils with different manurial treatments was only very approximately related to the cumulative K-yield.Less K was taken up from all Rothamsted soils given nitrogen fertilizer in the field and their K intensities were also smaller than the corresponding soils without ‘N’. Field liming of acid soils decreased their K-intensity and increased their K-buffer capacity, presumably because more potassium was removed by the field crop.A rapid method is suggested for measuring potassium intensities of soils.


2019 ◽  
Vol 49 (11) ◽  
Author(s):  
Jiayue Wan ◽  
Hexigeduleng Bao ◽  
Lihong Huang ◽  
Yanfei Ding ◽  
Zhixiang Chen ◽  
...  

ABSTRACT: Toxic metals contamination of soil has become a serious problem in recent years. In this study, Chinese cabbage (a relatively high-accumulator of cadmium (Cd)) and cabbage (a relatively low-accumulator of Cd) were cultured in monoculture and in intercropping in the Cd-contaminated soil, to evaluate the effect of intercropping on the alteration of Cd extraction. Both the pot experiments and field experiments indicated that intercropping increased the Cd extraction by Chinese cabbage and decreased the Cd extraction by cabbage. Thus, Cd extraction was advanced while safe production was obtained. Further pot experiment was conducted to investigate the alterations of soil Cd fractions, soil pH, and soil enzyme activities to reveal their possible relationship with Cd extraction between different planting patterns. Results revealed that three individual Chinese cabbages in one intercropping pot played the same effect on alteration of these factors as six individual Chinese cabbages in one monoculture pot. The intercropping increased Cd extraction by Chinese cabbage and decreased Cd extraction by cabbage, probably by influencing mechanisms such as soil enzyme activities (especially the urease activity) in the cultivation system. Effect of intercropping on Cd accumulation is an important issue in cultivation of vegetables in potentially contaminated land.


2019 ◽  
Vol 70 (4) ◽  
pp. 295 ◽  
Author(s):  
Geoffrey Anderson ◽  
Richard Bell

Soil acidity, or more specifically aluminium (Al) toxicity, is a major soil limitation to growing wheat (Triticum aestivum L.) in the south of Western Australia (SWA). Application of calcium carbonate (lime) is used to correct Al toxicity by increasing soil pH and decreasing soluble soil Al3+. Soil testing using a 0.01 m calcium chloride (CaCl2) solution can measure both soil pH (pHCaCl2) and soil Al (AlCaCl2) for recommending rates of lime application. This study aimed to determine which combination of soil pHCaCl2 or soil AlCaCl2 and sampling depth best explains the wheat grain-yield increase (response) when lime is applied. A database of 31 historical lime experiments was compiled with wheat as the indicator crop. Wheat response to lime application was presented as relative yield percentage (grain yield for the no-lime treatment divided by the highest grain yield achieved for lime treatments × 100). Soil sampling depths were 0–10, 10–20 and 20–30 cm and various combinations of these depths. For evidence that lime application had altered soil pHCaCl2, we selected the change in the lowest pHCaCl2 value of the three soil layers to a depth of 30 cm as a result of the highest lime application (ΔpHmin). When ΔpHmin &lt;0.3, the lack of grain-yield response to lime suggested that insufficient lime had leached into the 10–30 cm soil layer to remove the soil Al limitation for these observations. Also, under high fallow-season rainfall (228 and 320 mm) and low growing-season rainfall (GSR) (&lt;140 mm), relative yield was lower for the measured level of soil AlCaCl2 than in the other observations. Hence, after excluding observations with ΔpHmin &lt;0.3 or GSR &lt;140 mm (n = 19), soil AlCaCl2 provided a better definition of the relationship between soil test and wheat response (r2 range 0.48–0.74) than did soil pHCaCl2 (highest r2 0.38). The critical value (defined at relative yield = 90%) ranged from 2.5 mg Al kg–1 (for soil Al calculated according to root distribution by depth within the 0–30 cm layer) to 4.5 mg Al kg–1 (calculated from the highest AlCaCl2 value from the three soil layers to 30 cm depth). We conclude that 0.01 m CaCl2 extractable Al in the 0–30 cm layer will give the more accurate definition of the relationship between soil test and wheat response in SWA.


Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 571 ◽  
Author(s):  
D. P. Oliver ◽  
the late K. G. Tiller ◽  
A. M. Alston ◽  
G. D. Cozens ◽  
R. H. Merry

The effects of pH and soil-applied Cd on Cd concentration in wheat grain were determined using 4 soils in a glasshouse study. Grain Cd concentrations increased significantly (P < 0·001) with increasing applications of Cd for all soils. Generally, for the Alfisols the Cd concentration in grain decreased with increasing soil pH for all Cd treatments. The Cd concentrations in grain from plants grown on the Haploxerert showed variable responses to pH, depending on the Cd treatment. Smaller decreases in grain Cd concentration with increasing pH were seen on soils with native Cd compared with grain from soils to which Cd had been added. Generally, Cd uptake (mg/pot) by grain grown in the Alfisols showed the same trends with increasing pH as seen with grain Cd concentrations, indicating no yield dilution effect. On the Bordertown soil (a Palexeralf) the ratio of Cd in shoot material (excluding grain) to Cd concentration in grain was found to increase significantly (P < 0·001) with increasing Cd treatments and decrease significantly (P < 0·001) with increasing pH. The ratio on the Bordertown soil did not remain constant across Cd or pH treatments, which suggests that the use of soil tests to predict Cd concentration in grain may be problematical. The transfer coefficients for Kapinnie, Freeling, and Bordertown soils were dependent on pH, whereas that for the Inman Valley soil was independent of pH. The relationship between the reciprocal of the distribution coefficient (K¡ 1 d) and the transfer coefficients (Cd grain/Cd soil) was generally good for all soils except the Vertisol from Inman Valley.


2003 ◽  
Vol 8 (1) ◽  
pp. 41 ◽  
Author(s):  
A.S. Al-Busaidi ◽  
P. Cookson

Soil pH is the most commonly requested analysis undertaken during farm advisory work. Determination of pH assists in understanding many reactions that occur in soil. Variations in pH between soils have been related to a number of other soil parameters. In this study thirty different soils were collected from agricultural areas to have a wide range of pH, salinity, and texture. The objective was to study the relationship between soil pH and salinity. A negative relationship was found between soil salinity and pH. The main factor contributing to this relationship was probably the presence of soluble Ca2+ ion in soil. Variations in soluble Ca2+ ion concentrations between soils were negatively related to soil pH and positively related to soil salinity. Other soil properties that may affect pH, including CEC, CaCO3, clay content, gypsum and sodium adsorption ratio (SAR), were also determined. 


Weed Science ◽  
1985 ◽  
Vol 33 (4) ◽  
pp. 564-568 ◽  
Author(s):  
Wondimagegnehu Mersie ◽  
Chester L. Foy

The phytotoxicity of chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl] benzenesulfonamide} was compared in six soils, and the relationship of activity to soil physical and chemical properties was evaluated. The influence of soil pH (4.2 to 7.8) on phytotoxicity and adsorption of chlorsulfuron incorporated into high-organic-matter soil was also studied. For the phytotoxicity studies, corn (Zea maysL. ‘Pioneer 3320’) was used as the bioassay plant. Organic matter was the soil variable most highly correlated with chlorsulfuron phytotoxicity. There was an inverse relationship between phytotoxicity and organic matter. No significant relationship between clay content and chlorsulfuron toxicity was observed. The adsorption of chlorsulfuron decreased with increasing soil pH while desorption was greater at alkaline pH. Phytotoxicity of chlorsulfuron increased with increasing soil pH and reached a maximum at pH 6.9.


2009 ◽  
Vol 89 (4) ◽  
pp. 435-443 ◽  
Author(s):  
J -L Fan ◽  
N Ziadi ◽  
G Bélanger ◽  
L É Parent ◽  
A Cambouris ◽  
...  

Cadmium (Cd) is a heavy metal present in soils that can accumulate at relatively high levels in potato (Solanum tuberosum L.) with no negative effect on growth. Our objectives were to investigate Cd concentration in potato tubers produced in Quebec and to relate some soil characteristics, especially pH, P, and Cd, to tuber Cd concentration. Potato tubers (n = 75) and soil samples (n = 64) were collected from 1999 to 2006 at five experimental sites. Tuber Cd concentration ranged from 0.04 to 0.20 mg kg–1 dry matter (DM), with a median value of 0.11 mg kg–1 DM, and never exceeded the proposed tolerance for potato of 0.05 mg kg–1 fresh weight or about 0.25 mg kg–1 DM. Tuber Cd concentration was weakly, although not significantly, related to soil available P content (r2 = 0.53, P = 0.064), indicating a possible influence of soil P on Cd uptake by potato. Tuber Cd concentration was not directly related to soil pH, or to DTPA- or Mehlich 3-extractable Cd in soils. The log-transformed tuber Cd concentration was significantly (r2adj = 0.87, P < 0.01) related to both soil pH and VCd13, a generated variable that accounts for interactions between soil Cd and clay content, soil organic matter, and soil concentrations of Fe, Al, Mn, P, K, S, Ca, Cu, Zn, and B. Single factors such as soil Cd, soil P, or pH could not solely explain Cd accumulation in tubers; interactions between selected soil properties and soil Cd should be considered.Key words: Cadmium, phosphorus, Solanum tuberosum L., accumulation


2006 ◽  
Vol 2 (1) ◽  
pp. 51-72
Author(s):  
István Patay ◽  
Virág Sándor

Clod crushing is a principal problem with soils of high clay content. Therefore, there is a need for determining the conditions for clod breaking and clod crushing. The objective of the work was to develop a special purpose tool for single clod breaking both by rigid support of the clod and by a single clod supported by soil and to develop a machine for clod crushing. Furthermore, the purpose was to determine the relationship between the specific energy requirement for clod crushing in the function of soil plasticity and the soil moisture content by the means of the developed tool and machine. The main result of the experiments is summarized in a 3D diagram where the specific energy requirement for soil clod crushing is given in the function of the moisture content and the plasticity index for different clay soils.


2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.


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