Organic farming systems benefit biodiversity and natural pest regulation in white cabbage

Natural regulation of cabbage root flies works well in experimental organic cropping systems of white cabbage. Low input and complex organic systems benefit functional biodiversity by providing good living conditions to several groups of natural enemies. Intercropped green manure benefits large predators while small predatory beetles favour low input organic systems with bare soil between crop rows

Økologisk dyrkning af hvidkål fremmer biodiversitet og naturlig regulering af skadedyr

Naturlig regulering af kålfluer er effektiv i økologisk dyrkede hvidkålsparceller. Økologiske dyrkningssystemer med lavt input og høj strukturel kompleksitet skaber gode livsbetingelser for en række nyttedyr. Mellemafgrøder af foregående sæsons grøngødning gavner de store arter, mens små løbe- og rovbiller bliver tilgodeset i et økologisk system med bar jord mellem afgrøderækkerne

An ecological future for weed science to sustain crop production and the environment. A review

Sustainable strategies for managing weeds are critical to meeting agriculture's potential to feed the world's population while conserving the ecosystems and biodiversity on which we depend. The dominant paradigm of weed management in developed countries is currently founded on the two principal tools of herbicides and tillage to remove weeds. However, evidence of negative environmental impacts from both tools is growing, and herbicide resistance is increasingly prevalent. These challenges emerge from a lack of attention to how weeds interact with and are regulated by the agroecosystem as a whole. Novel technological tools proposed for weed control, such as new herbicides, gene editing, and seed destructors, do not address these systemic challenges and thus are unlikely to provide truly sustainable solutions. Combining multiple tools and techniques in an Integrated Weed Management strategy is a step forward, but many integrated strategies still remain overly reliant on too few tools. In contrast, advances in weed ecology are revealing a wealth of options to manage weedsat the agroecosystem levelthat, rather than aiming to eradicate weeds, act to regulate populations to limit their negative impacts while conserving diversity. Here, we review the current state of knowledge in weed ecology and identify how this can be translated into practical weed management. The major points are the following: (1) the diversity and type of crops, management actions and limiting resources can be manipulated to limit weed competitiveness while promoting weed diversity; (2) in contrast to technological tools, ecological approaches to weed management tend to be synergistic with other agroecosystem functions; and (3) there are many existing practices compatible with this approach that could be integrated into current systems, alongside new options to explore. Overall, this review demonstrates that integrating systems-level ecological thinking into agronomic decision-making offers the best route to achieving sustainable weed management

Variable effects of organic farming systems on ground beetle abundance and diversity

Organic farming should support high levels of biodiversity and rely on biological pest control by natural enemies. Management of organic systems must comply with specific regulations, but within this frame management is not clearly defined. In experimental cabbage fields we studied ground beetle abundance and diversity in three different organic farming systems (O1, O2, and O3). All systems complied with regulations for organic production, but relied on either high (O1) or low (O2 and O3) external input of nutrients. The systems O2 and O3 also included green manures, and in O3 strips of green manure were left between crop rows. A conventional system was included as control. Only organic systems O2 and O3 showed benefits for ground beetles, but in different ways. Abundance of all ground beetle species was highest in May in O2, while O3 supported the highest abundance of habitat specialists with preferences for field margins reflecting the conservation of green manure strips. The ground beetle community of O3 was most diverse characterized by highest number of species and evenness (equitability among species). Organically farmed fields can therefore be designed to promote specific predators or high ground beetle diversity at the field scale by implementing different management practices