Performance und Ertragsbildung von Winterweizen im DOK-Versuch

Wheat yield performance and bread baking quality was investigated in the DOK long term experiment in Switzerland. Yield and crude protein differed between biological and conventional systems but not between bio-organic and bio-dynamic systems. The same observations were made for yield components and baking quality parameters. Potatoes as preceding crops compared to maize performed much better than increased manure application in biological systems

Ertrag von Mais und Sojabohnen im biologischen und konventionellen Anbausystem des DOK-Versuchs

Sustainable food and feed production is becoming a major issue with regard to the growing world’s population and the scarcity of non-renewable resources such as energy and fertilizers. Long-term trials offer the unique opportunity to assess the performance of cropping systems over decades, providing meaningful data. While many studies have proven, that organic farming generally increases soil fertility and biodiversity, long-term productivity of organic systems is questioned. Here we show that across all crops of a seven year rotation, yields of the organic system were approx. 81% of those of the conventional system in the fifth rotation period of the DOK trial (2006-2012), but with much lower input of nutrients and pesticides. Two major food and feed staple crops, maize and soybean, manifested a different picture. While soybean yields were slightly higher (5%) under organic management, yields of maize were 9% lower in the organic system. These data suggest that long-term productivity of organic systems is possible, while maintaining other ecological services

Phosphor- und Kalium-Bilanzen über 35 Jahre DOK-Versuch & geschätzte K-Nachlieferungsraten auf einem Lössboden

We calculated a phosphorus (P) and potassium (K) balance for the DOK-trial (Therwil, Switzerland) for a 35-years cropping period. In the DOK-trial, three cropping systems (D: biodynamic, O: bioorganic and K: conventional) are maintained on both a full (2) and a halved (1) fertilization level. Additionally, a treatment with no fertilization (N) and mineral fertilization (M; since 1985) are included. Balance inputs included fertilization, deposition, nutrients inputs by seeds, while in the outputs removal of nutrients by harvested plant material and leaching was considered. For P, the balance was positive for treatment M and treatment O2, but negative for the other treatments. The K-balance was positive only for treatment M, while treatments D2, O2 and K2 showed a slightly negative K-balance. In general, extensively maintained treatments on the halved fertilization level as well as treatment N show a negative P and K-Balance. Due to relatively constant K-concentrations and K-removal by crops in treatment N for the last 3 cropping periods (7 years each) we estimated a supply potential of K from loess soil of approximately 50 kg/ha * yr

Auf lange Dauer gute Erträge in Bio

Die Erträge im Biolandbau sind auch für die wichtigen Kulturen Mais und Soja gut, das zeigt der DOK-Langzeitversuch

Bons rendements bio sur la durée

L’essai DOC montre que les rendements de l’agriculture bio sont aussi bons dans des cultures comme le maïs et le soja

Bodenfruchtbarkeit und biologische Vielfalt im ökologischen Landbau

Um die Effektivität landwirtschaftlicher Anbausysteme zu beurteilen, bedarf es eines Verständnisses der Agrarökosysteme. Eine 21-jährige Studie ergab 20 Prozent geringere Erträge bei ökologischen Anbausystemen gegenüber konventionellen, obgleich der Einsatz von Düngemitteln und Energie um 34 bis 53 Prozent und der von Pestiziden um 97 Prozent geringer war. Wahrscheinlich führen die erhöhte Bodenfruchtbarkeit und die größere biologische Vielfalt in den ökologischen Versuchsparzellen dazu, dass diese Systeme weniger auf Zufuhr von außen angewiesen sind

DOK-Versuch: Nährstoffversorgung in Winterweizen – Wo wird es eng?

Das Ziel des seit 1978 durchgeführten DOK-Systemversuchs in Therwil BL ist der Vergleich zwischen einem biologisch-dynamischen (D), einem organisch-biologischen (O), einem konventionellen (K; organisch-mineralische Düngung) und einem konventionell-mineralischen (M; ausschliesslich mineralische Düngung) Anbausystem im Hinblick auf nachhaltigen Pflanzenbau und Bodenfruchtbarkeit. Der Versuch verfügt über zwei Düngungsniveaus (Tab. 1) und erlaubt die Untersuchung der Einflüsse unterschiedlicher Nährstoffversorgung auf die Ertragsbildung und Aussagen zu Limitierungen einzelner Pflanzennährstoffe

Organic cropping systems maintain yields but have lower yield levels and yield stability than conventional systems – Results from the DOK trial in Switzerland

Sufficient and stable crop yields are the basis for feeding a growing world population. Limited cropland, climate change, degradation of soil quality and loss of biodiversity coupled with excessive use of non-renewable resources require new solutions for future cropping systems beyond existing management practices. Here we analyzed mean yields, temporal yield trends and the stability of organic and conventional cropping systems from the currently longest-lasting cropping system comparison, the DOK long-term systems comparison trial (DOK) comparing biodynamic, bioorganic and conventional cropping systems, over a period of 40 years. We used yield data of winter wheat, potatoes, grass-clover, maize and soybean in a seven-year rotation, where bioorganic and biodynamic farming systems were compared with conventional mixed and sole mineral fertilized systems. System treatments have been established at a reduced half and a regular fertilization level, which corresponds to standard Swiss farming practices. Yields were significantly lower in organic systems in non-legumes between 13% and 34%, depending on the investigated crop, whereas in legumes, no yield reduction was observed in soybean and only 10% was observed in grass-clover. Half the amount of fertilizer reduced yields by around 10% in all systems and crops. Applied mineral N determined yields mainly in winter wheat and potatoes. Temporal yield trends did not differ between organic and conventional systems, nor between half and regular fertilization over all crops. However, in winter wheat, both conventional and biodynamic management with regular fertilization showed a stronger temporal increase in yield, while yield of grass-clover under biodynamic management with half-fertilization decreased. Increased yield differences between systems in single years were due to poor performance of organic systems rather than better performance of conventional systems. Absolute stability (measured by the variance) did not differ, but conventional systems were more stable than organic ones in relative stability, measured by the coefficient of variation, expressing the stability in relation to the yield level. We found no difference in both absolute and relative stabilities between half and regular fertilization. Long-term organic management results in lower yields than conventional management, but not in a decrease of yields over time. The similarity in both stability measures between half and regular fertilization suggests that the variation in relative stability between organic and conventional management might be more related to plant protection than to fertilization intensity

Stickstoffbilanzen in biologischen und konventionellen Anbausystemen Das Effizienz-Nachhaltigkeits-Dilemma

N-balances over 35 years from the DOK trial are presented and combined with Nstock changes in DOK treatments on different fertilisation levels. Results strongly indicate an N efficiency-sustainability dilemma: DOK treatments with a high nitrogen use efficiency (NUE) lose more soil stock N than those with a lower NUE but higher N losses from the system. The biodynamic system showed little advantage in terms of soil N stocks sustainability while the solely mineral fertilised conventional treatment had highest NUE across all inputs including soil N change

Life Cycle Assessment of Conventional and Organic Farming in the DOC trial

The environmental impacts of the conventional and organic farming systems practised in the DOC trial (organic-dynamic, organic and conventional farming) have been assessed by the SALCA life cycle assessment method. Both organic farming systems were more favourable for the environment in all investigated impacts per area unit. When analysed per product unit, clear advantages of organic farming were found for ecotoxicity and the use of mineral resources, while energy use and eutrophication were similar to conventional farming. Reducing fertilisation by 50% led to lower or equal environmental impacts for all systems, depending on the impact category and the functional unit. The analysis of single crops revealed large differences that are partly counterbalanced by other crops in the crop rotation. The eco-efficiency of organic potato production in particular should be improved