Relation between magnetic parameters and nematode abundance in agricultural soils of Portugal—a multidisciplinary study in the scope of environmental magnetism

Abstract

Soil is composed of different types of particles which are either natural or of anthropogenic origin. Anthropogenic particles are often related to the presence of heavy metals and thus provide information on soil quality. Magnetic parameters can detect the presence of such particles and may be used as a proxy for environmental pollution. This study explores the relationships between magnetic particles and the nematofauna of agricultural soils. Magnetic, pedological, microscopy and nematological analyses were conducted in soils collected from major regions of potato production in Portugal. The magnetic characterisation of soils identified regions with magnetic particles with possible anthropogenic origin. Microscopy analysis revealed the presence of spherical particles dominantly composed of Fe, O and C. A positive and significant relationship was found between saturation isothermal remanent magnetisation (SIRM) and mass-specific susceptibility (χ), confirming the importance the ferrimagnetic fraction to magnetic properties. The nematode communities were composed of nematodes belonging to four trophic groups (bacterial feeding, plant feeders, fungal feeders and omnivores/predators). The relationships between magnetic parameters and the nematodes showed that (1) S −25 has a linear correlation with number of nematodes per kilogram of soil and with plant feeders' trophic group and (2) SIRM correlates with the bacterial feeders trophic group. This study reveals that magnetic proxies may provide means for detecting regions with higher levels of pollution, possibly related to heavy metals. Due to the large background variability found in magnetic parameters, the sampling spacial mesh should to be further refined and the input of magnetic minerals needs to be locally calibrated.

Magnetic Susceptibility Profile, Fe Content and pH Analysis of Apple Orchard Soil and the Relation to Fruit Diameter

“…More specifically, the research on soil magnetic properties in the plantation land is also intended for understanding the soil condition. As an example of illustration to the difference between the pesticidepolluted soil and without pesticide (Agustine et al, 2013) and its correlation to soil magnetic properties with the existence of nematode fossils (Lourenço et al, 2015). This study on magnetic properties aimed to investigate in detail the soil magnetic properties and their impact on plants, both its quality and the amount of plant production.…”

Magnetic susceptibility of the southern chernozems of Ukraine, case study from Odessa region

“…Розглянемо деякі приклади. У міждисциплінарній роботі [15] розглядається зв'язок між магнітними влас-тивостями ґрунтів та вмістом нематодів (види червів) у ґрунтових фракціях. Визначається якість ґрунтів та мо-жливість їх подальшого використання у сільському гос-подарстві на основі визначення магнітних показників.…”