Umweltwirkung und Produktivität von biologischen und konventionellen Systemen - Ergebnisse aus 42 Jahre DOK Versuch

Ergebnisse aus 42 Jahren Systemvergleichsversuch im DOK (Therwil,CH) zeigen das biologische im Vergleich zu konventionellen Systemen kritische Umweltbelastungen (Biodiversität, Nährstoffe, Treibhausgasemissionen) reduzieren und dabei stabilen aber um 15% verringerten Ertrag erzielen

Evidence confirms an anthropic origin of Amazonian Dark Earths.

Arising from: Silva et al. Nature Communications https://doi.org/10.1038/s41467-020-20184-2 (2021

Umweltwirkung und Produktivität von biologischen und konventionellen Systemen - Ergebnisse aus 42 Jahre DOK Versuch

Die Landwirtschaft ist eine der Haupttriebkräfte des globalen Wandels, und es werden dringend Produktionssysteme benötigt, die die Umwelt schonen. Der ökologische Landbau wird als Alternative zu konventionellen Anbausystemen angesehen, da er sich auf die Gesundheit der Böden und die langfristige Nachhaltigkeit konzentriert. Messungen über einen Zeitraum von 42 Jahren im DOK-Versuch, dem ältesten landwirtschaftlichen Systemvergleichsexperiment der Welt zeigen, dass Kohlenstoff und Stickstoff im Boden durch organischen Dünger stabilisiert und bei ausschließlicher Verwendung von Mineraldünger verringert werden

45 Jahre DOK-Versuch: Der Beitrag verschiedener Anbausysteme für die Erhaltung der Bodenfruchtbarkeit

Vortrag über 45 Jahre DOK-Versuch: die biodynamische Bewirtschaftung macht das Bodenleben vielfältiger und dadurch entsteht Boden- sprich Humusaufbau

No effect on biological or chemical soil properties when amended with effective microorganisms for improved cover crop decomposition

The implementation of cover crops into a crop rotation can contribute to a more sustainable soil management. For the improved decomposition of cover crop residues, the commercial inoculant Effective Microorganisms® (EM) is increasingly applied. Despite its extensive application, comprehensive studies on the effect of EM application on soil processes are lacking, since rarely a clean differentiation between an EM-effect (induced by living EM directly) or a substrate effect (induced by the accompanying EM substrate) is made. To determine the potential effects of EM application after cover crop integration to soil we conducted a lab incubation experiment under spring-like conditions in temperate climates and applied EM either on bare soil or on cover crops prior to soil incorporation at recommended and 100 times the recommended doses. Control groups included treatments with no EM addition and a sterilized EM solution applied at 100 times the recommended dose. Over a monitoring period of 28 days, the application of EM at the recommended dose showed no consistent effect on soil respiration, microbial bound carbon or nitrogen, soil pH, permanganate oxidizable carbon or water extractable nutrients and trace elements. Any observed effects in the treatment that received 100 times the recommended dose was attributed to the substrate introduced with the EM solution rather than the living EM themselves. Amplicon sequencing showed that certain EM taxa could be detected in soil at low abundance after EM application, but only when EM were applied at 100 times the recommended dose. We conclude that the application of EM did not produce a discernible effect on soil biological or chemical properties, nor did it influence the decomposition process of the cover crop

Crop production and environmental performance in organic and conventional farming systems. Results from a 42 years old field experiment

Agricultural systems put severe pressure on the environment, and management practices balancing the need for agricultural production and environmental health are urgently needed. Key environmental challenges for agricultural systems include the reduction of nutrient losses, the mitigation of greenhouse gas emissions and the preservation of soil biodiversity. Organic farming systems are proposed as environmentally friendly alternative to conventional systems due to their focus on long-term soil quality, but often show lower yields. Long-term field trials are the backbone to assess the impact of farming systems on agronomic and environmental parameters. In this study we present the results from a 42-year-old field trial (DOK trial), located in Therwil, CH on key agronomic and environmental parameters. The trial compares two organic (BIODYN, BIOORG) and two conventional (CONFYM, CONMIN) farming systems with an unfertilized control (NOFERT) and follows a system comparison approach. Farming systems mainly differ in plant protection and fertilization strategy but follow the same tillage strategy and 7-year crop rotation. CONFYM receives the highest external inputs in terms of nutrients and chemical plant protection followed by CONMIN, BIOORG, and BIODYN. Across the five main crops, (grass-clover, wheat, potato, maize, and soybean) organic farming systems maintained yields at ~85% of conventional systems with distinct differences between legume and non-legume crops. Farming systems receiving organic inputs at a rate of 1.4 livestock units per hectare and year stabilized (BIOORG, CONFYM) or even enhanced (BIODYN) soil organic carbon and nitrogen stocks. Yet, soil organic carbon and nitrogen contents evolved slowly and differences became statistically significant only after 22 years. All fertilized farming systems showed a positive nitrogen balance when nitrogen fixation via legumes was included. Still purely mineral fertilized (CONMIN) and unfertilized (NOFERT) systems lost soil organic carbon and nitrogen on the long term. Organic farming systems significantly reduced soil borne climate impacts, which was rather driven by nitrous oxide emissions than by changes in soil organic carbon contents. Higher richness of soil fauna, and weed population was observed in organic farming systems, next to enhanced biological soil quality indicators. The functional potential of the soil microbiome showed a gradual change from organic (BIODYN, BIOORG) to conventional (CONFYM, CONMIN) systems highlighting the impact of farming systems on soil functions With the present study, we could show that with moderate yields gaps organic farming systems can reduce pressure on the environment by enhancing soil functionality for critical ecosystem services

Benefits and Challenges of organic soil management

Agriculture feeds a growing world population, but is also one of the main causes of the global environmental crisis. The sustainable use of soil as a resource is the key challenge for the agricultural sector. Using the example of the 45-year-old DOK trial near Basel, the opportunities for organic farming to provide important ecosystem services in the long term will be demonstrated. The lecture will focus on the effects of conventional and organic land use systems on soil quality indicators such as soil carbon, soil biology and greenhouse gas emissions. In addition, the limitations of organic land use systems will be discussed and further food for thought on sustainable land use will be provided