Linking soil properties and nematode community composition: effects of soil management on soil food webs

Abstract

The purported benefits of conservation tillage and continuous cropping in agricultural systems include enhancement of soil ecosystem functions to improve nutrient availability to crops and soil C storage. Studies relating soil management to community structure allow the development of bioindicators and the assessment of the consequences of management practices on the soil food web. During one year (December 2003-December 2004), we studied the influence of continuous cropping (CC), intermittent fallow (F), standard tillage (ST) and no tillage (NT) on the nematode assemblage and the soil food web in a legume-vegetable rotation system in California. The most intensive systems included four crops during the study period. Tillage practices and cropping pattern strongly influenced nematode faunal composition, and the soil food web, at different soil depths. Management effects on nematode taxa depended on their position along the coloniser-persister (cp) scale and on their trophic roles. At the last sampling date (December 2004), Mesorhabditis and Acrobeloides were positively associated with NH + 4 , while Panagrolaimus and Plectus were negatively correlated with certain phospholipid fatty acids (PLFA). Microbial-feeders were in general associated with both bacterial and fungal PLFA, microbial biomass C (MBC) by chloroform fumigation-extraction, total C and N, NH + 4 and NO − 3 , and were most abundant in the surface soil of the NTCC treatment. Fungal-feeders were more closely related to PLFA markers of fungi than to ergosterol, a purported fungal sterol. Discolaimus, Prionchulus, Mylonchulus and Aporcelaimidae, in contrast, were associated with intermittent fallow and deeper soil layers. The organisms in the higher levels of the soil food web did not respond to the continuous input of C in the soil and a long recovery period may be required for appropriate taxa to be reintroduced and to increase. At the end of the experiment, each treatment supported quite different nematode assemblages and soil food webs.

Soil nematode responses to fertilization with ammonium nitrate after six years of unfertilized apple orchard

“…Different letters indicate significant differences (p < 0.05) among treatments or Growing seasons × Sampling times interaction according to Tukey test. of predators and omnivores (Sánchez-Moreno et al, 2006). Hánel (2010) found that Aporcelaimellus increased in abandoned fields, and this taxon was one of the most common at the beginning of our study.…”

Abundance and diversity of soil nematodes as influenced by different types of organic manure

“…terised by several trophic behaviour and respond readily to environmental changes thus playing an important role in soil food web (Neher, 2001;Sánchez-Moreno et al, 2006). In this system different groups of trophic nematodes are closely correlated with other soil organisms whose activities affect primary production, soil matter decomposition, energy flows, cycle of nutrients, especially nitrogen and phosphorus cycles (Sochová et al, 2006).…”

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

“…Since bacterial feeders, known to influence soil mineralisation, are usually abundant in cultivated soils while predators and omnivores often disappear with cultivation (Fu et al 2005;Wardle et al 1995), the results obtained may therefore be typical of those found in agricultural soils. Natural areas are known to support lower nematode diversity, when compared with cropped fields (Neher et al 2005;Sánchez-Moreno et al 2006). In this study, a maximum of ten nematode families were found in soils from Faro and Guarda, and in the other regions, nematodes were grouped in eight to nine families.…”