Schneckenanfälligkeit von Zwischenfrüchten

Cover crops are in disreputable to promote noxious snails in arable fields, which can negatively impact the following main crop. Agroscope have tested the susceptibility of 25 cover crop species against the grey field slug (Deroceras reticulatum). Results elucidate the possibility to regulate the slug population with a proper choice of cover crop species. Best results were obtained with lupine, vetch, serradella, phacelia, oilseed radish, mustard, oat, buckwheat and summer flax

Drohnenbilder zur Untersuchung von Pflanzenwachstum und Nährstoffdynamik

Ein besseres Verständnis der Dynamik hinter der Freisetzung von pflanzenverfügbaren Nährstoffen aus Boden oder organischen Dünger und eine Verbesserung der Nährstoffverwertung von Ackerfrüchten sind zwei wichtige Herausforderungen, um die Produktivität im ökologischem Ackerbau zu erhöhen. Doch diese Prozesse sind stark sowohl von biotischen (z.B. Bodenmikroben) als auch abiotischen (z.B. Temperatur, Niederschlag, Bodenfeuchtigkeit, Bodenstruktur) Faktoren beeinflusst und erschweren effiziente Untersuchungen. Fernbilderkundung-Technologien (remote sensing) haben sich in den letzten Jahren stark weiterentwickelt und bieten heute neue Ansätze und Methoden, um der Ernährungsstatus von Pflanzen sowie die Dynamik des Pflanzenwachstums nicht destruktiv zu untersuchen. In diesem Beitrag wird, anhand ersten Untersuchungen, die Möglichkeit aus Drohnenbilder Pflanzenwachstum-Parameter zu erfassen und das Potential dieser Technik für wissenschaftliche Untersuchungen und agronomische Beratung diskutiert

Within-plant distribution of induced resistance in apple seedlings: rapid acropetal and delayed basipetal responses

Induction of plant resistance by herbivory is a complex process, which follows a temporal dynamic and varies spatially at the within-plant scale. This study aimed at improving the understanding of the induction process in terms of time scale and within-plant allocation, using apple tree seedlings (Malus×domestica) as plant model. Feeding preferences of a leaf-chewing insect (Spodoptera littoralis) for previously damaged and undamaged plants were assessed for six different time intervals with respect to the herbivore damage treatment and for three leaf positions. In addition, main secondary defense compounds were quantified and linked to herbivore feeding preferences. Significant herbivore preference for undamaged plants (induced resistance) was first observed 3days after herbivore damage in the most apical leaf. Responses were delayed in the other leaf positions, and induced resistance decreased within 10days after herbivore damage simultaneously in all tested leaf positions. Chemical analysis revealed higher concentrations of the flavonoid phloridzin in damaged plants as compared to undamaged plants. This indicates that herbivore preference for undamaged apple plants may be linked to phloridzin, which is the main secondary metabolite of apple leaves. The observed time course and distribution of resistance responses within plants contribute to the understanding of induction processes and patterns, and support the optimal defense theory stating young tissue to be prioritized. Moreover, induced resistance responses occurred also basipetally in leaves below the damage site, which suggests that signaling pathways involved in resistance responses are not unidirectiona

Water uptake patterns of pea and barley responded to drought but not to cropping systems

Agricultural production is under threat of water scarcity due to increasingly frequent and severe drought events under climate change. Whether a change in cropping systems can be used as an effective adaptation strategy against drought is still unclear. We investigated how plant water uptake patterns of a field-grown pea–barley (Pisum sativum L. and Hordeum vulgare L.) mixture, an important fodder intercrop, responded to experimental drought under four cropping systems, i.e. organic intensive tillage, conventional intensive tillage, conventional no tillage, and organic reduced tillage. Drought was simulated after crop establishment using rain shelters. Proportional contributions to plant water uptake from different soil layers were estimated based on stable water isotopes using Bayesian mixing models. Pea plants always took up proportionally more water from shallower depths than barley plants.Water uptake patterns of neither species were affected by cropping systems. Both species showed similar responses to the drought simulation and increased their proportional water uptake from the shallow soil layer (0–20 cm) in all cropping systems. Our results highlight the impact of drought on plant water uptake patterns for two important crop species and suggest that cropping systems might not be as successful as adaptation strategies against drought as previously thought

Limited capability of organic farming and conservation tillage to enhance agroecosystem resilience to severe drought

CONTEXT: Climate change increasingly threatens food security, particularly through prolonged phases of drought. It is therefore important to evaluate and develop arable cropping systems with an enhanced capability to withstand severe drought events to ensure food production. However, it is still poorly understood whether specific management strategies, in particular organic farming and conservation tillage that are thought to be more resilient to drought, can enhance the ability of agroecosystem to withstand drought. OBJECTIVE: The main objective of this study was, therefore, to test the ability of organic farming and conservation tillage practices to withstand drought within expected boundaries of climate scenarios for the end of the century. METHODS: This study summarizes the effects of drought (both natural and experimental) on the productivity of three arable crops (maize, pea-barley mixture and winter wheat) assessed in three consecutive years in a longterm cropping system field experiment. We tested whether four relevant cropping systems (i.e., conventional and organic with and without soil conservation tillage) differ in their ability to reduce the impact of drought on plant yield and crop performance. We studied conditions of moderate natural drought (summer 2018) and severe experimental droughts using rainout shelters (3 years) after 8 years of contrasting field management. RESULTS AND CONCLUSIONS: We found pronounced and consistent yield reductions due to experimental drought events for all cropping systems (34% for maize, 23% for pea-barley, and 17% for winter wheat). Drought induced yield reductions were largely similar across the four cropping systems, suggesting very limited capacity of any cropping system to buffer severe drought. Yet, there was an obvious but insignificant trend in maize in 2018 where under moderate and experimental drought conservation tillage resulted in a higher on-average yield compared to the plowed systems. Furthermore, drought resulted in lower nitrogen (N) uptake by the crops and a positive N budget, which could result in higher N losses after a drought period. SIGNIFICANCE: This study demonstrates that drought has consistent and adverse effects on crop productivity under conventional, organic and soil conservation arable cropping. It further demonstrates that it is difficult to find effective adaptation strategies for arable systems under realistic future scenarios and underlines the need to combine all available practices, from soil management to crop and cultivar choice, to mitigate drought impacts on crop productivity

Shallow non-inversion tillage in organic farming maintains crop yields and increases soil C stocks: a meta-analysis

Reduced tillage is increasingly promoted to improve sustainability and productivity of agricultural systems. Nonetheless, adoption of reduced tillage by organic farmers has been slow due to concerns about nutrient supply, soil structure, and weeds that may limit yields. Here, we compiled the results from both published and unpublished research comparing deep or shallow inversion tillage, with various categories of reduced tillage under organic management. Shallow refers to less than 25 cm. We found that (1) division of reduced tillage practices into different classes with varying degrees of intensity allowed us to assess the trade-offs between reductions in tillage intensity, crop yields, weed incidence, and soil C stocks. (2) Reducing tillage intensity in organic systems reduced crop yields by an average of 7.6 % relative to deep inversion tillage with no significant reduction in yield relative to shallow inversion tillage. (3) Among the different classes of reduced tillage practice, shallow non-inversion tillage resulted in non-significant reductions in yield relative to deep inversion; whereas deep non-inversion tillage resulted in the largest yield reduction, of 11.6 %. (4) Using inversion tillage to only a shallow depth resulted in minimal reductions in yield, of 5.5 %, but significantly higher soil C stocks and better weed control. This finding suggests that this is a good option for organic farmers wanting to improve soil quality while minimizing impacts on yields. (5) Weeds were consistently higher, by about 50 %, when tillage intensity was reduced, although this did not always result in reduced yields

Carbon Sequestration By Organic Conservation Tillage – A Comprehensive Sampling Campaign In Nine European Long-Term Trials

Conservation tillage is suggested to sequester carbon although a stratification of soil organic carbon rather than a total increase is mostly observed. It is not clear whether conservation tillage in combination with organic farming practices has a higher potential. Beyond, many datasets are biased in terms of sampling depth. A joint sampling campaign in nine European long-term trials considered soil organic carbon stocks until 100 cm soil depth comparing reduced tillage with ploughing under organic farming conditions. First results show a significant increase of carbon stocks in 0-30 cm and also in 0-100 cm depth with the conversion to reduced tillage

Wirtschaftlichkeit von pfluglosen Anbausystemen: Resultate für Winterweizen aus einem Anbauversuch

There is an increased interest in Europe to develop organic farming systems with reduced tillage intensity. Besides technical and agronomical aspects, the profitability of these systems has to be viable for farmers to achieve a successful implementation in practice. A long-term trial was set up in 2009 at the research station Agroscope Reckenholz-Tänikon (ART) to compare conventional and organic farming systems with and without ploughing including a full cost calculation to assess the profitability of the different systems. First results show that the highest benefit was obtained under organic cultivation under Swiss legislation. Moreover, production costs were reduced with the adoption of conservation tillage