Biochemical indicators of soil fertility in vineyards with different conservative management systems

Abstract

Biochemical parameters are particularly suited to evaluate soil fertility because soil microorganisms play a pivotal role in determining soil quality and functionand are very sensitive to changes in soil management and environmental conditions. For such reasons, in this work, we used several biochemical indexes to assess the effect on soil fertility of 3 different conservative management systems of vineyards. The managements compared were chemical weed control vs permanent grass (CWC/MWC), land levelling vs undisturbed soil (LL/US), conventional farming vs organic farming (CON/ORG). The following parameters were determined in 2014 and 2015 on soil samples: total organic C (TOC), extractable N (EN), soil basal respiration (SBR), microbial biomass C (BC), microbial quotient (BC/TOC) and metabolic quotient (qCO2 = SBR/BC). Results showed that biochemical indicators were effective in detecting changes in soil fertility between compared systems. In particular, conservative systems (MWC, US and ORG) showed a larger and more efficient microbial biomass and enhanced EN content in comparison to the relative conventional systems. Furthermore BC/TOC and qCO2 indicated higher C use efficiency in conservative systems. Results as a whole indicate that conservative management systems aimed to maintain and enhance soil organic matter displayed a higher level of soil fertility.