Grössere Biomassen und aktivere mikrobielle Gemeinschaften in Böden unter biologischer Bewirtschaftung eine globale Meta-Analyse

Population growth, climate change and other impacts challenge our food and farming system and provide arguments for further intensification in agriculture. One option is eco-functional intensification through organic farming, an approach based on exploiting internal natural resources and processes for securing and improving agricultural productivity whilst minimizing negative environmental impacts. In this concept an active soil microbiota plays a crucial role. Thus, we conducted a literature search followed by meta-analysis to quantify possible differences in key indicators for soil microbial abundance and activity in organic and conventional farming systems. We integrated data from 57 studies including 148 pairwise comparisons and found significant differences for almost all investigated effect sizes. Microbial biomass carbon and nitrogen, total phospholipid fatty acids, basal respiration, dehydrogenase, urease and protease activity were increased up to 84% in organic systems. The metabolic quotient remained unaffected with regard to the overall effect. Summarizing, this study shows that long-term organic farming enhances microbial abundance and activities in agricultural soils