Call for contributions

Zero hunger

Soil management principles in climate-smart conservation <BR>agriculture to halt and reverse land degradation (Communication session)

EUROSOIL2020CONT-1610

25 YEARS OF « OBERACKER » FOR A CLIMATE-FRIENDLY AND SOIL-CONSERVING AGRICULTURE OF THE FUTURE

Wolfgang G. Sturny^{* 1}, Andreas Chervet¹, Peter Hofer¹, Claudia Maurer¹, Lorenz Ramseier¹, Regula Schwarz¹, Peter Trachsel¹, Marc Zuber¹

¹Bern Office of Agriculture & Nature, Switzerland

Content: The 25-year’s studies of the long-term field experiment Oberacker in Switzerland reveal that Conservation Agriculture in line with a long-standing continuous no-tillage system is a suitable alternative to the conventional plow system.

Plowed topsoils do indeed create better germination and development conditions shortly after sowing, which is particularly beneficial for tuber and root crops. At the same time, however, the risk of compaction increases in the subsoil, especially under wet conditions. In contrast, higher nutrient availability in the topsoil, enhanced aeration of the subsoil and greater supply of plant available soil water under no-tillage result in higher yields for legumes and cereals. Cost accounting shows that no-tillage is still economical compared to other cropping systems as a result of increased yields and ecological contributions. It also contributes valuably to erosion control.

The C_org- and N_tot-contents under no-tillage are significantly higher in the topsoil layer than after plowing. Over the entire profile no higher C-sequestration was observed in no-tilled than in plowed soil.

Despite higher application rates in the no-tillage than in the plow system, neither more glyphosate nor more of the breakdown product AMPA was detected in the soil. Merely an accumulation was found in the uppermost 5 cm of the no-tilled soil. But no reduction in the amount and species diversity of earthworms and arbuscular mycorrhizal fungi could be observed – on the contrary: in all crops there are significantly more species under no-tillage (ø 18.5) as compared to plowing (ø 13.2). An important and simple figure for enforcement is the maximum carrying axle load. Loads >5 t mean that, especially in wet growing seasons, the number of trafficable days without risk of subsoil compaction is counted.

Overall, the aim for the future is a low-input (relay) cropping system based on N- and P-recycled fertilizers with maximum energy and resource efficiency by means of a minimum use of auxiliary substances. This requires changes in the way how to drive on and till the soil. In order to preserve the functionality of our soils and to keep more of the environmental compartments intact, a holistic approach is needed that takes several concerns into account simultaneously: protecting the climate, conserving the soil, maintaining the landscape, reducing natural hazards, keeping waters clean and – last but not least – producing our food.

Disclosure of Interest: None Declared

Keywords: glyphosate substitution, moldboard plowing, no-tillage, soil ecosystem services, yield