Crop rotation in no-till soils modifies the soil fatty acids signature

FERRARI A; RAVNSKOV S; WALL LG

SOIL USE AND MANAGEMENT

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 34 p. 427 - 436

0266-0032

Analysis of whole-soil fatty acids (WSFA) was used to characterize no-till productive agricultural soilsassociated with different crop rotation managements on the Argentinean pampas, over two samplingseasons. Crop rotation (CR) treatment was compared with soybean monocropping (MC). Soils fromnearby natural environments (NE) were used as reference treatments. The objective of this study wasto characterize the soil lipid signature and seek putative markers of agricultural management. NEsites had greater concentration of total WSFA than agricultural sites, but no differences between CRand MC were identified. NE sites were characterized by straight chain and mono-unsaturated fattyacids, such as 16:1x5c, an established biomarker for arbuscular mycorrhiza. Comparing lipid profilesusing multivariate methods allowed a comprehensive comparison among treatments. The CR and NEsoil samples were more alike than those of MC, with several fatty acids in common. CR soils wereassociated with mixed, branched and hydroxylated fatty acids. MC profiles appeared to be enrichedby 16:010Me and 18:1x7c fatty acids, which could be potential treatment markers. Thus, use of theWSFA approach to study soil lipid signature appeared to be a sensitive method to characterize soilhealth and soil use and management. However, some of the fatty acids do not come from living cellsbut from soil organic matter, which sets a limitation on interpretation in terms of the microbialcommunity but expands the biological origin of the soil lipid signature to any biological matter, aliveor death, which is a constitutive part of the soil under study.