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Budapest, Hungary

Czira G.,Kornyezettudomanyi Doktori Iskola Debreceni | Simon L.,College of Nyiregyhaza | Vincze G.,College of Nyiregyhaza | Koncz J.,Agrokemiai Intezet | Lakatos G.,Kornyezettudomanyi Doktori Iskola Debreceni
Agrokemia es Talajtan | Year: 2013

In Hungary, the remediation of soils contaminated with explosives and ammunition residues is of interest both for the environment and for the national economy. A slightly basic sandy soil with low humus and high salt and lime content, collected from a Hungarian shooting range and ammunition destruction site, was found to be contaminated with 900 mg·kg-1 Pb and 133 mg·kg-1 Cu.The purpose of phytoextraction (as a soil remediation technique) is to transfer heavy metals from soil to the harvestable plant organs, thus reducing the mobile pool of toxic elements in the contaminated soil. The present investigations aimed to determine whether the accumulation of Pb and Cu in maize organs could be stimulated by the application of EDTA, EGTA or citric acid chelants to soil contaminated with ammunition residues or artificially contaminated with Pb. A pot experiment was set up with maize (Zea mays L., cv. Furio) to investigate the phytoextraction of Cd, Cu, Pb and Zn from the soil of the shooting-range and from uncontaminated soil collected close to the shooting-range and artificially contaminated with 100 mg·kg-1 Pb.The roots of maize grown on contaminated soil without chelants accumulated 554 μg·g-1 Pb, while eight times this amount (4611 μg·g-1) was detected after soil treatment with 0.5 g·kg-1 of EDTA. The Pb concentration in the shoots increased from 158 to 302 μg·g-1 (91%). In the case of artificially Pb-contaminated soil, the Pb concentration was enhanced from 164 to 775 μg·g-1 in the roots and from 44.1 to 71.3 μg·g-1 in the shoots after EDTA application. All these changes were statistically significant.The Cu uptake was significantly stimulated by 0.5 g EGTA, increasing from 516 μg·g-1 in the roots of untreated cultures to 1063 μg·g-1 in treated cultures. Although the increase in the shoots was 69% (from 29.9 to 50.7 μg·g-1), this change was not significant.Citric acid did not enhance the translocation of lead into the shoots, and its influence on copper uptake was only significant in the roots.None of the chelants influenced the Cd or Zn accumulation in maize.Based on the results of the pot experiment, it could thus be concluded that EDTA, and to a certain extent EGTA, were able to influence the phytoavailability and mobility of Pb and Cu in contaminated soils, thereby promoting the accumulation of these toxic elements in plants. The field application of these chelants can thus be expected to result in the partial removal of the Pb or Cu contamination with the harvested plants.

Kadar I.,Agrokemiai Intezet
Agrokemia es Talajtan | Year: 2013

Interactions were studied between the elements K, B and Sr in poppy in 1998, in the 11th year of an experiment set up on pseudomyceliar (calcareous) chernozem soil at the Experimental Station of the Institute in Nagyhörcsök.Basic fertilization generally consisted of 100 kg each of N and P2O5 per hectare per year, given in the form of 25% calcium ammonium nitrate and superphospate. The K levels were adjusted using repeated doses of 0, 1000 and 2000 kg K2O, the B levels with repeated doses of 0, 20, 40 and 60 kg B and the Sr levels with 0 and 67 kg Sr per hectare, applied in the form of 60% KCl, 11% borax and 33% SrCl2·6H2O. The main plots were the 3 K treatments, the subplots the 4 B treatments and the sub-subplots the 2 Sr treatments, giving a total of 24 treatments × 3 replications = 72 plots in a split-plot design.When the experiment was set up in autumn 1987 the ploughed layer contained 5% CaCO3, 3% humus and 20% clay. The pH (H2O) value was 7.8 and the pH (KCl) 7.3. The AL-soluble K 2O and P2O5 values were 180-200 and 100-200, the KCl-soluble Mg 110-150, the KCl+EDTA-soluble Mn 60-80, the Cu and Zn 1-2 and the B 0.7 mg·kg-1. The soil nutrient supplies were satisfactory for K, Ca and Mg, moderate for N and P and poor for Zn and Cu. The groundwater was at a depth of 13-15 m and the area was prone to drought. The mean temperature averaged 11 C and the annual rainfall sum was 400-600 mm, with uneven distribution.The poppy variety Kompolti M was sown at a depth of 1-2 cm on 16 March 1998 with a row distance of 45 cm. The agronomic measures and methodological observations are presented in Table 1.The main conclusions were as follows:

Kadar I.,Agrokemiai Intezet | Csatho P.,Agrokemiai Intezet
Agrokemia es Talajtan | Year: 2013

Interactions between the elements N and Cu were examined in a field experiment on spring barley set up on pseudomyceliar (calcareous) chernozem soil in 1988. The soil contained 3% humus, around 5% CaCO3 and around 20% clay in the ploughed layer. Soil analysis showed the nutrient supply level to be good for Ca, Mg, K and Mn, satisfactory for Cu, moderate for N and poor-to-moderate for P and Zn. The groundwater was at a depth of 13-15 m and the area was prone to drought.The experiment was set up in a split-plot design with 4N×3Cu = 12 treatments × 3 replications = 36 plots. The N rates (0, 100, 200 and 300 kg N·ha-1) were applied in the form of calcium ammonium nitrate and the Cu rates (0, 50 and 100 kg Cu·ha -1) as CuSO4. The rainfall was only a third of the usual quantity in April and May and half in July. The spring barley variety Mars, used as indicator plant, was sown at a depth of 5 cm with a row distance of 12 cm, and a seed number of 60-70·m-2 and 200 kg·ha -1. The plant stand was scored on a 1-5 scale in each plot at the tillering, flowering and harvesting stages. After harvest, soil samples were taken from the ploughed layer, forming mean samples from 20 drillings per plot. Ten elements were analysed in the plant samples, while in the soil samples the KCl-EDTA-soluble Cu content and the KCl-exchangeable NH4-N and NO3-N contents were determined.The main results were as follows: li-N fertilizer rates of 100-300 kg·ha-1led to a 20-25% loss of grain yield after perennial legume alfalfa as preceding crop. Cu fertilization had no effect at all, as the soil had satisfactory Cu supplies. The average yield level was only 3 t·ha-1 grain and 3 t·ha -1 by-products. The N requirements of the low yield achieved in this dry year could be satisfied even by the unfertilized soil when grown after the N-fixing crop alfalfa. The macro-and microelement contents of the shoots at tillering increased, however, with the exception of Na and Zn as the N supplies increased. The incorporation of the nutrients N, Ca, Mn and Cu in the straw and grain at harvest was also stimulated by N fertilization. Cu fertilization had no effect on the plant composition. Copper was accumulated primarily in the roots, where the Cu concentration rose steeply from 28 mg·kg-1 in the control to 144 mg·kg-1 as the Cu supplies increased. The nutrients N, P, Mg, Zn and Cu were enriched to the greatest extent in the grain. The specific element contents of spring barley (in 1 t grain + corresponding byproducts) amounted to 32 kg N, 19 kg K2O, 12 kg P2O 5, 6 kg CaO and 4 kg MgO. These data could be useful to the extension service for the estimation of the nutrient requirements of the planned yield of spring barley. It should be noted that the specific nutrient contents of the low yields averaged around 20% more than in normal years. In addition the specific N content reflected the excessive N supply resulting from the application of 100-300 kg N·ha-1 after a legume forecrop. After the first year practically the whole of the Cu fertilizer applied could be detected in the ploughed layer in KCl+EDTA form. The 2 mg·kg -1 Cu content recorded in the control soil rose steeply to 22 and 44 mg·kg-1 in response to the addition of 50 and 100 kg Cu·ha-1·year-1, resp. The transport of Cu within the plant (vertically) was, however, inhibited.

Kadar I.,Agrokemiai Intezet | Ragalyi P.,Agrokemiai Intezet
Agrokemia es Talajtan | Year: 2013

The effects of diverse N, P and K supply levels and their combinations on the yield, mineral nutrient contents and nutrient uptake of a mixture of eight grass species without legumes, having meadow fescue (Festuca pratensis) as the main component, were studied in the 36th year of a long-term mineral fertilization experiment in 2009. The soil contained 3% humus, 3-5% CaCO 3 and 20-22% clay in the ploughed layer, and was originally supplied moderately with N and K and poorly with P and Zn.The experiment included 4N×4P×4K = 64 treatments × 2 replications = 128 plots. The groundwater was at a depth of 13-15 m and the area was prone to drought. Before the first cut (on 26 May) the area received 119 mm rainfall, with a further 124 mm until the second cut on 12 August. During this 2.5 month period the maximum daily temperature was generally around 30 C or more.The main results were as follows:

  • -A hay yield of 0.8 t·ha-1 was achieved in the two cuts on the control plot, unfertilized for 36 years, and 6.4 t·ha-1 at the highest NPK rate. The mean hay mass in the autumn cut was 63% of the mean value in the May cut. N and the N×P interaction had the most decisive effect, but no yield loss was caused by the highest PK supplies or N rate.-In the first cut there was a rise in the N, NO3-N, Mn, Zn, Ba and Cu contents of the hay as the N supplies increased, a rise in the P, S and Sr with an increase in P and a rise in K concentration with an increase in K supplies. However, N fertilization caused a reduction in K, P, B and Mo, P fertilization in NO3-N, Zn and Mo, and K fertilization in the cations Ca, Mg, Na, Sr and Cr.-In the first cut the following ranges of element concentrations were observed in the N×P and N×K treatments: N 1.05-1.86%, K 0.55-1.52%, Ca 0.45-0.65%, P 0.13-0.34%, Mg 0.13-0.22%, Na 0.02-0.23%, NO3-N 52-405 mg·kg-1, Zn 12-24 mg·kg-1, Sr 11-23 mg·kg-1, Mo 0.3-2.1 mg·kg-1, Cr 0.2-0.4 mg·kg-1.-The quantities of elements incorporated into the hay at the first cut exhibited the following minimum and maximum values per hectare, depending on the treatments: 5-60 kg N, 7-37 kg K, 2-16 kg Ca, 1-5 kg P and S, 1-4 kg Mg, 0.1-3.4 kg Na, 5-58 g Sr, 7-49 g Zn, 1-2 g Mo. Similar values were recorded for the element contents and element uptake in the second cut.-In the second cut the mean concentrations of the elements were 20-50% higher than in the first cut, due to the smaller yield. N fertilizer led to an increase in the N and NO3-N contents, P fertilizer in the P and Sr, and K fertilizer in the K content. The quantity of other elements was generally reduced by higher NPK rates. The quantities of elements taken up averaged 25-30% of those in the first cut for Na and Ni, 50-70% for K, Ca, Al, S, Cu and Mo, and 70-90% for N, Ca, Mg, Sr, Ba, B and Zn (due to their greater accumulation in aging hay).

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