02745nas a2200229   4500008004100000245010100041210006900142260006800211300001200279490000700291520192200298653001602220653001402236653001202250653002802262653002102290653001202311100001902323700001902342700001902361856013502380       2009                        eng d00aEffects of cover crop quality and quantity on nematode-based soil food webs and nutrient cycling0 aEffects of cover crop quality and quantity on nematodebased soil  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BV  a157-1670 v413 aSoil food webs cycle nutrients and regulate parasites and pathogens, services essential for both agricultural productivity and ecosystem health. Nematodes provide useful indicators of soil food web dynamics. This study was conducted to determine if nematode soil food web indicators and crop yield can be enhanced by combinations of cover crops in a conservation tillage system. The effects of three cover crop treatments (vetch/pea, oat/wheat and oat/wheat/pea/vetch) with low, medium and high C:N and a bare fallow control were investigated in Davis, CA. Nematode fauna, Soil Properties and plant productivity were measured. Soil food web indices, including the Enrichment index (EI), Structure Index (SI), Basal Index (BI), and Channel Index (CI), based on the composition of nematode assemblages, were calculated to infer soil food web condition. Cover cropped tomato/corn rotations had twice the number of enrichment opportunist bacterial feeding nematodes, active participants in nitrogen mineralization, than fallowed tomato/corn rotations (opportunist bacterial feeders = 163 versus 98). In winter fallowed plots food webs were basal, common in disturbed, nutrient-poor conditions (BI = 37). Total number of enrichment opportunist nematodes, soil NH4-N levels, and inferred nitrogen mineralization, were higher in cover crop treatments with low to mid C:N ratios. Omnivore and predator nematodes were scarce, averaging less than 6 nematodes 100 g(-1) in all treatments. in year one, plant productivity was highest after fallow. In contrast, in year two productivity was highest after cover crops with high nitrogen content and productivity significantly correlated with the structure of the soil fauna. Monitoring the abundance of enrichment opportunists may provide managers with a new tool to evaluate soil food web nitrogen mineralization and plant productivity. (C) 2008 Elsevier B.V. All rights reserved.10aCover crops10aFood webs10aLegumes10aNitrogen mineralization10aNutrient cycling10aOrganic1 aDuPont, Tianna1 aFerris, Howard1 aVan Horn, Mark  uhttps://nematoda.myspecies.info/content/effects-cover-crop-quality-and-quantity-nematode-based-soil-food-webs-and-nutrient-cycling02900nas a2200229   4500008004100000245010900041210006900150260009100219300001200310490000600322520203200328653001602360653001102376653002502387653001802412653001202430100002502442700002302467700001902490700002402509856013702533       2006                        eng d00aLinking soil properties and nematode community composition: effects of soil management on soil food webs0 aLinking soil properties and nematode community composition effec  aPLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDSbBRILL ACADEMIC PUBLISHERS  a703-7150 v83 aThe 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 NH4+, 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, NH4+ and NO3-, 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.10aCover crops10afallow10anematode sensitivity10asoil food web10atillage1 aSanchez-Moreno, Sara1 aMinoshima, Hideomi1 aFerris, Howard1 aJackson, Louise, E.  uhttps://nematoda.myspecies.info/content/linking-soil-properties-and-nematode-community-composition-effects-soil-management-soil-food