Pollution Of Agricultural Land Research Articles

Fertility status, trace elements and heavy metal pollution of agricultural land irrigated from the Gediz River

The effect of the Gediz River, polluted by industrial and domestic wastes, on fertility status and trace elements and heavy metal pollution of agricultural land irrigated from this river was investigated. For this purpose, soil samples were collected in August 1998 between the source of the Gediz River (Murat Mountain) and its mouth (Aegean Sea). Soil samples were collected from 12 different sites along the length of the river basin from 0-30 cm depth. The soils were slightly alkaline, with no salt problem and were poor in organic matter. Total N and available P, K, Mg, Fe and Zn levels were low or average, whereas available Ca, Na, Cu, Mn were present at good and sufficient levels. Thirty three per cent of soils had available B and S of soils had total B levels above the phytotoxic lower boundary. Because of the geographical/geological structure, soil samples from the Gediz source (Sample Site 1) had high amounts of total Fe, Zn, Mn, B, Cd, Ni, Cr and Co. At the second sampling site, total Ni content was also higher than is acceptable according to the national standards set. In addition, in some soil samples the amount of total Cd was above the lower phytotoxic boundary value.

Fertility status, trace elements and heavy metal pollution of agricultural land irrigated from the Gediz River

Fertility status, trace elements and heavy metal pollution of agricultural land irrigated from the Gediz River

Evaluation of surface- and ground-water pollution due to herbicides in agricultural areas of Zamora and Salamanca (Spain)

The pollution of agricultural land due to herbicides was assessed in the Guareña and Almar river basins, situated in the provinces of Zamora and Salamanca (Spain). A set of fifteen herbicides, including triazines, ureas, amides and others, was selected owing to their frequency of use, the amounts used, their toxicity and their persistence in the environment. Solid-phase extraction with polymeric cartridges, followed by HPLC with diode-array detection, were used to monitor the herbicides. This technique was chosen owing to the wide range of functionality and polarity of the analytes under study. The detection limits obtained were in the 0.004–0.025 μg/l range ( λ=220 nm). Surface and ground waters, taken from different locations in the basins, were analyzed over a 6-month period. The presence of six out of the fifteen herbicides monitored — chlortoluron, atrazine, terbutryn, alachlor, diflufenican and fluazifop-butyl — was detected in several samples at levels ranging from the detection limit to 1.2 μg/l. The relationship of these herbicides to the agricultural activities of the zone is discussed.

Review: A bioavailability-based rationale for controlling metal and metalloid contamination of agricultural land in Australia and New Zealand

Metal pollution of agricultural land in Australia and New Zealand is less severe than that documented in many European countries, due to the lower density of urban developments and a lower level of industrialisation. However, Australia and New Zealand are highly dependent on plant production systems based on plant-microbial symbioses (e.g. Rhizobium, mycorrhizae) and other natural biogeochemical processes for maintaining nutrient status in soils that are generally low in nutrients and, in Australia, also low in organic matter. Data linking metal concentrations in soil to agricultural and ecological effects are sparse for Australia and New Zealand, and regulatory frameworks and guidelines to control metal contamination of soils rely heavily on data generated in countries of the northern hemisphere. Adoption of benchmark concentrations for metal contaminants from these countries has led to inappropriate levels being chosen for several elements. These problems could be avoided and metal contamination of soils could be more effectively controlled if instead of relying on total concentrations of metals in soil and soil amendments, regulations and guidelines considered the biologically active fractions. This review considers the advantages and disadvantages of a bioavailability-based approach to the control of metal contamination of soils and suggests improvements needed to avoid both over- and under-protective measures.