Metals in vineyard soils of the Penedès area (NE Spain) after compost application

Effects of Leonardite Amendments on Vineyard Calcareous Soil Fertility, Vine Nutrition and Grape Quality

Vineyard calcareous soils are usually low in organic matter, which makes them prone to physical, chemical, and biological degradation. Besides, these soils are also usually poor in various nutrients in plant-available form, e.g., iron. To make up for this lack of soil fertility, on the one hand, manures, and on the other, iron chelates are usually used. However, the soil application of these materials is not free from problems, and other amendments based on leonardites could be advantageously used as an alternative. Therefore, two organic amendments, one leonardite alone (1 Mg/ha), and the other leonardite (1 Mg/ha) plus ferrous sulphate heptahydrate (0.5 Mg/ha), were tested for three years in a commercial vineyard calcareous plot under Mediterranean climate. The effects of these amendments on soil fertility, plant nutrient contents, and berry quality were studied against a control of bare soil by means of a fully randomized trial with three repetitions per treatment. Soil organic matter (SOM) increased as a consequence of both leonardite treatments, but much more than expected on the basis of a simple mass transfer from the amendments. With the ferrous-sulphate-heptahydrate-supplemented leonardite, the increase in SOM was noticeably higher. This is explained on the basis of nutrient quantity and intensity-pH-related effects, which increased soil nutrient plant-availability and presumably enhanced vine root growth. In response to the higher plant availability of nutrients, the petiole nutrient concentrations were observed to increase under the leonardite treatments. However, only a trend to increase potassium in petioles and in grape must, linked to a decrease of grape must pH, was observed in harvest quality under the leonardite treatments. Leonardite and adequately supplemented leonardite seem to have potential for increasing SOM contents and nutrient plant-availability, thus improving the soil fertility of vineyard calcareous soils.

Content and bioavailability of trace elements and nutrients in grape pomace

BACKGROUND

The possible agricultural use of grape pomace could be limited by the content and mobility of metals. This is influenced by many factors. In this study, the abundance and availability of heavy metals and essential nutrients were evaluated comprehensively in different grape pomace residues from winemaking of five white and red grape varieties, before and after the distillation process.

RESULTS

The total metal content found in grape pomace skins and seeds confirmed that there was greater metal accumulation in skins than in the corresponding seeds, with the exception of Ca and Mg. The enrichment of all metals (except K) during the distillation stage was confirmed by means of a significant correlation (R = 0.996, P < 0.001) between the metal content obtained in distilled and undistilled samples. Regarding availability, multivariate statistical analysis showed different behavior among elements, but a great similarity for metal mobility in both distilled and undistilled grape pomace samples and in both skins and seeds, except for Mn, Zn and Mg.

CONCLUSION

The results obtained in this study suggest the potential application of these grape residues as organic fertilizers for agricultural soils, without limitations resulting from heavy metal contamination. © 2019 Society of Chemical Industry.

Stability and heavy metal distribution of soil aggregates affected by application of apatite, lime, and charcoal

Only a few studies have been reported on the stability and heavy metal distribution of soil aggregates after soil treatments to reduce the availability of heavy metals. In this study, apatite (22.3 t ha(-1)), lime (4.45 t ha(-1)), and charcoal (66.8 t ha(-1)) were applied to a heavy metal-contaminated soil for 4 years. The stability and heavy metal distribution of soil aggregates were investigated by dry and wet sieving. No significant change in the dry mean weight diameter was observed in any treatments. Compared with the control, three-amendment treatments significantly increased the wet mean weight diameter, but only charcoal treatment significantly increased the wet aggregate stability. The soil treatments increased the content of soil organic carbon, and the fraction 0.25-2 mm contained the highest content of soil organic carbon. Amendments' application slightly increased soil total Cu and Cd, but decreased the concentrations of CaCl2 -extractable Cu and Cd except for the fraction <0.053 mm. The fractions >2 and 0.25-2 mm contained the highest concentrations of CaCl2-extractable Cu and Cd, accounted for about 74.5-86.8 % of CaCl2-extractable Cu and Cd in soil. The results indicated that amendments' application increased the wet soil aggregate stability and decreased the available Cu and Cd. The distribution of available heavy metals in wet soil aggregates was not controlled by soil aggregate stability, but possibly by soil organic carbon.

Concentrations of Trace Elements in Organic Fertilizers and Animal Manures and Feeds and Cadmium Contamination in Herbal Tea (Gynostemma pentaphyllum Makino)

Thailand is predominantly an agriculture-based country. Organic farming is enlisted as an important national agenda to promote food safety and international export. The present study aimed to determine the concentrations of trace elements in commercial organic fertilizers (fermented and nonfermented) composed of pig and cattle manures available in Thailand. Pig and cattle manures as well as animal feeds were also collected from either animal farms or markets. The results were compared to the literature data from other countries. Fermented fertilizer composed of pig manure contained higher concentrations of nitrogen (N) and phosphorus (P) than fertilizer composed of cattle manure. High concentrations of copper (Cu) and zinc (Zn) were also found in fertilizers and manures. Some organic fertilizers had high concentrations of arsenic (As), cadmium (Cd), and lead (Pb). The range of As concentration in these fertilizers was 0.50-24.4 mg/kg, whereas the ranges of Cd and Pb were 0.10-11.4 and 1.13-126 mg/kg, respectively. Moreover, pig manure contained As and Cd (15.7 and 4.59 mg/kg, respectively), higher than their levels in cattle manure (1.95 and 0.16 mg/kg, respectively). The use of pig manure as soil supplement also resulted in high Cd contamination in herbal tea (Gynostemma pentaphyllum Makino; GP). The Cd concentration in GP plants positively correlated with the Cd concentration in the soil. Therefore, the application of some organic fertilizers or animal manures to agricultural soil could increase some potentially toxic elements in soil, which may be absorbed by plants and, thus, increase the risk of contamination in agricultural products.

Vertical distribution and analysis of micro-, macroelements and heavy metals in the system soil-grapevine-wine in vineyard from North-West Romania

BACKGROUND

The determination of micro-, macroelements and heavy metals in the soil-grapevine-wine system is extremely important for the wine industry, the grape and wine quality, and also for consumer health. The quantitative analysis of 10 elements: Na, Ca, Mg, Fe, Cu, Zn, Pb, Cd, Ni, Co were made in soil at different depths and also in grapevines (leaves and canes). For grape juice and wine there were analyzed the concentrations of Cu, Zn, Pb, Ni and Cd on three cultivars Fetească albă, Fetească regală and Riesling italian, located in Turulung vineyard, NW Romania. All the elements were detected using flame atomic absorbtion spectrometry (FAAS).

RESULTS

Only the Cu concentration [Formula: see text] has higher values than the maximum limit admitted (20 mg/kg). The concentrations of micro-, macroelements and heavy metals in aerial parts of grapevine cultivars occur in the following order: Ca > Na > Mg > Fe > Cu > Zn > Ni > Pb > Co > Cd in canes and leaves. Cu, Pb, Ni and Zn concentration levels decreased in wine compared to grape must, possibly forming insoluble components that can be removed through sedimentation together with yeasts and lees during fermentation. Cd was under the limit of detection. Heavy metals detected in Romanian wines were below the recommended health limits of the International organization of wine and vine (O.I.V.).

CONCLUSIONS

In soil, all the elements studied were under the maximum limit admitted, except, elevated concentrations of Cu. These high values obtained could be an effect of different Cu treatments in vineyards. In canes and leaves, Cu, Zn, Pb, Cd, Ni had higher concentration levels than in grape juice (must) and wine. Conversely, the metal acumulation of wines obtained by micro-vinification process (in the laboratory) are lower than in must.

Effect of two biogas residues' application on copper and zinc fractionation and release in different soils

Biogas residue (BR) is widely used as a new green fertilizer in agriculture in China. However, it often contains a high concentration of heavy metals so its application should cause our concern. An incubation experiment was conducted to study the risk of pig biogas residue (PBR) and chicken biogas residue (CBR) application on Liuminying soil (LS) and Yixing soil (YS). The soils were incubated for one, three and six months with 0, 2%, 4% and 6% addition of BRs. According to BCR extraction results, the PBR and CBR applications induced an increase in the concentration of exchangeable fraction of Zn. As for the concentration of exchangeable fraction of Cu, an increase was only observed in the treatments with PBR application. The heavy metal binding intensity also showed a similar trend. With the PBR application, for the LS and YS, the highest concentrations of exchangeable Zn increased 3.6 and 9.5 times, respectively, while the exchangeable Cu was increased by 52.6% and 187.1%. Dissolved organic carbon was the limiting factor for the exchangeable Cu while the exchangeable Zn was controlled by soil pH. PBR presented more agricultural risk than CBR when used as fertilizer. Meanwhile, BRs were more adaptable to LS than YS according to the heavy metal release results.

Long-term variability of metals from fungicides applied in amended young vineyard fields of La Rioja (Spain)

The long-term variability of total Cu content from fungicides applied in a certified wine region of Spain (La Rioja) and of other metals (Cd, Cr, Ni, Pb, and Zn) was evaluated in three young vineyard soils and subsoils unamended and amended with spent mushroom substrates (SMS) over a 3-year period (2006-2008). SMS is a promising agricultural residue as an amendment to increase the soil organic matter content but may modify the behaviour of metals from pesticide utilisation in vineyards. Fresh and composted SMS was applied each year at a rate of 25 t ha(-1) (dry-weight). Copper concentrations in the three unamended soils were 21.2-88.5, 25.5-77.1, and 29.4-78.4 mg kg(-1). They exceeded natural Cu concentrations of the region and reference sub-lethal hazardous concentration for soil organism. The concentrations of Cd, Ni, Pb, and Zn were largely below the sub-lethal limits. Thus, although Cu levels were lower than those of established vineyards, vine performance, and productivity might be affected. The variation in behaviour between different amendments for each soil was high, so a generic conclusion could not be drawn. The amendment practice seemed to have caused temporarily Cu mobilization respect to untreated soils. Total zinc concentrations fall within the range of the natural soil of La Rioja and were significantly affected (p < 0.05) especially by fresh state SMS addition, with increasing up to 75% respect to untreated specimen. The results indicated a build-up of fresh sites for metal retention at both surface and subsurface level, although no accumulation of metals was observed in the short-term period. However, the benefit for soils and the negative effects need to be monitored in the long run.

Zinc distribution and acid-base mobilisation in vineyard soils and sediments

Nineteen vineyard stands located in steep-slope areas of three wine-growing regions in northwest Spain were selected for this study. In each stand, a representative soil sample (19) and one or two sediment samples (24) were collected. In these samples, the Zn distribution in the solid phase was assessed. Moreover, the effect of pH on the release of zinc was determined using a batch-type experiment. The mean zinc concentration (109 mg kg(-1)) of the samples was lower than the maximum concentrations allowed by the European Union. Moreover, most of the zinc that appeared in vineyard soils was residual zinc, suggesting a tendency for zinc in these soils to be irreversibly bound to soil components, reducing its potential environmental impact. In sediments, the mean total Zn concentration (126 mg kg(-1)) was higher than those in the original soils and in the mobile fractions, which could mean a higher risk of liberation. Zinc release was higher under acidic conditions, in which release depends mainly on labile fractions. Under basic conditions, the release of Zn was lower and depended on Zn bound to crystalline oxyhydroxides.

Inventory of heavy metal content in organic waste applied as fertilizer in agriculture: evaluating the risk of transfer into the food chain

BACKGROUND, AIM, AND SCOPE

In this work, an environmental risk assessment of reusing organic waste of differing origins and raw materials as agricultural fertilizers was carried out. An inventory of the heavy metal content in different organic wastes (i.e., compost, sludge, or manure) from more than 80 studies at different locations worldwide is presented.

MATERIALS AND METHODS

The risk analysis was developed by considering the heavy metal (primarily Cd, Cu, Ni, Pb, and Zn) concentrations in different organic residues to assess their potential environmental accumulation and biotransfer to the food chain and humans. A multi-compartment model was used to estimate the fate and distribution of metals in different environmental compartments, and a multi-pathway model was used to predict human exposure.

RESULTS

The obtained hazard index for each waste was concerning in many cases, especially in the sludge samples that yielded an average value of 0.64. Among the metals, Zn was the main contributor to total risk in all organic wastes due to its high concentration in the residues and high biotransfer potential. Other more toxic metals, like Cd or Pb, represented a negligible contribution.

CONCLUSIONS

These results suggest that the Zn content in organic waste should be reduced or more heavily regulated to guarantee the safe management and reuse of waste residues according to the current policies promoted by the European Union.

FeS-coated sand for removal of arsenic(III) under anaerobic conditions in permeable reactive barriers

Iron sulfide (as mackinawite, FeS) has shown considerable promise as a material for the removal of As(III) under anoxic conditions. However, as a nanoparticulate material, synthetic FeS is not suitable for use in conventional permeable reactive barriers (PRBs). This study developed a methodology for coating a natural silica sand to produce a material of an appropriate diameter for a PRB. Aging time, pH, rinse time, and volume ratios were varied, with a maximum coating of 4.0 mg FeS/g sand achieved using a pH 5.5 solution at a 1:4 volume ratio (sand: 2 g/L FeS suspension), three days of aging and no rinsing. Comparing the mass deposited on the sand, which had a natural iron-oxide coating, with and without chemical washing showed that the iron-oxide coating was essential to the formation of a stable FeS coating. Scanning electron microscopy images of the FeS-coated sand showed a patchwise FeS surface coating. X-ray photoelectron spectroscopy showed a partial oxidation of the Fe(II) to Fe(III) during the coating process, and some oxidation of S to polysulfides. Removal of As(III) by FeS-coated sand was 30% of that by nanoparticulate FeS at pH 5 and 7. At pH 9, the relative removal was 400%, perhaps due to the natural oxide coating of the sand or a secondary mineral phase from mackinawite oxidation. Although many studies have investigated the coating of sands with iron oxides, little prior work reports coating with iron sulfides. The results suggest that a suitable PRB material for the removal of As(III) under anoxic conditions can be produced through the deposition of a coating of FeS onto natural silica sand with an iron-oxide coating.

Total and available soil trace element concentrations in two Mediterranean agricultural systems treated with municipal waste compost or conventional mineral fertilizers

The temporal dynamics of some trace elements in two different types of Mediterranean soils were studied in order to evaluate the possible long-term contamination following compost amendments. Total and available (DTPA-extractable) concentrations of Cd, Cu, Pb and Zn were determined. The study was carried out on two agricultural soils in Campania region (southern Italy), a Sandy Loam Calcaric Cambisol (SG) and a Clay Gleyc Luvisol (CO), during 3 years of organic amendment with compost. The compost, produced from the organic fraction of municipal solid waste and urban yard trimmings, in accordance with the Italian law for agricultural use, was applied at annually rates of 15, 30, and 45 t ha(-1) (on dry weight basis). Wide variations in total and available Cd, Cu, Pb and Zn concentrations were observed over time, but appeared to be in many cases unrelated to the treatments, occurring also in control plots. After 3 years of compost application the amended SG soil showed the highest and significant increase in total Cd and Zn concentrations; in addition, the available Cd, Pb and Zn concentrations increased in accordance with the compost rates. The CO soil, characterized by a higher clay content, lower organic matter content and lower cation exchange capacity, exhibited a lower increase in available metal fractions. Our findings show that compost amendment affects more the available than the total metal concentrations in the two types of soils studied and thus it is important into legislation that metal "bioavailability" may be considered in defining threshold metal values.

Contamination of vineyard soils with fungicides: a review of environmental and toxicological aspects

The contamination of agricultural soils with inorganic (Cu-based) and organic pesticides (including their residues) presents a major environmental and toxicological concern. This review summarizes available studies published on the contamination of vineyard soils throughout the world with Cu-based and synthetic organic fungicides. It focuses on the behavior of these contaminants in vineyard soils and the associated environmental and toxicological risks. The concentrations of Cu in soils exceed the legislative limits valid in the EU in the vast majority of the studied vineyards. Regarding the environmental and toxicological hazards associated with the extensive use of fungicides, the choice of fungicides should be performed carefully according to the physico-chemical properties of the soils and climatic and hydrogeological characteristics of the vine-growing regions.

Differential absorption of metals from soil to diverse vine varieties from the Valley of Tulum (Argentina): consequences to evaluate wine provenance

We report the effect of vine variety on the absorption of metals from soil and follow the variety from wine through juice, verifying which metals could be used to assess wine provenance. Eleven metals were determined by atomic absorption spectroscopy in 32 soils, 16 grapes juices, and 18 wines sampled from a single vineyard having four red grape varieties (Cabernet Sauvignon, Bonarda, Malbec, and Syrah). The K nearest neighbor method allows us to distinguish among different soils, juices, and wines. Linear discriminant analysis affords descriptors to point out differences, mainly Mg, Mn, Ca, K, and Na. Data analysis evidenced that some elements have equivalent concentrations in soil, juice, and wine, while others did not. Canonical analysis shows good correlation between grape juice and wine with their provenance soil. We suggest using Mg as a marker of wine provenance, while Mn could be used to evaluate differences between wine varieties associated with plant physiology.

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of the both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic matter (OM) became predominance for Zn and organic bound Cu occupied the largest portion. There was more available amount for Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to deltaEXCH and deltaCAR forms but also in deltaOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by deltaEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.