Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Abstract
Harvest Weed Seed Control (HWSC) systems are used to collect and/or kill weed seeds in the chaff fraction during grain harvest. While collecting chaff reduces the weed infestation in the following years, a new biomass feedstock is created. Chaff mainly consists of husk and straw. There is a potential energetic utilization of chaff. It can also be used as a material for construction (e.g., insulating boards, cardboard, bedding), soil improvement (e.g., mulch, mushroom compost) and agricultural use (e.g., weed growth inhibitor, animal diet). Using chaff directly is unfavorable because of low bulk density; therefore, compressing chaff into pellets optimizes its handling. We have assessed how pelletizing would affect germination of weed seeds bearing in the chaff if the collected chaff is pelletized for further utilization. To test this, we mixed original wheat chaff and fine wheat chaff (pretreated by sieving) with each of the weed species Tripleurospermum inodorum and Centarea cyanus seeds separately. Approximately 2000 seeds of each weed species were added to 2500 g of chaff (20 % moisture). Samples were pelletized using the Kahl Pelleting Press 14-175. Each treatment was replicated four times. Afterwards pelletized samples were spread evenly on the soil surface in 14 × 16 cm boxes and covered by a thin layer of soil/sand. Unpelletized chaff samples were used as control. Boxes were placed in greenhouse and watered from the bottom and seed germination was followed for a month. While on average 22 and 59 % seed germination of T. inodorum and C. cyanus were observed in wheat chaff control samples respectively, no weed seed germination was observed in pelletized fine and original wheat chaff samples. Consequently, we find that the pelletizing process of collected chaff destroys the weed seeds in it.
Abstract
Harvest weed seed control takes advantage of seed retention at maturity by collecting weed seeds as they pass through the harvester. We assessed the seed production and shedding pattern of common weed species in two wheat and two oat fields in Denmark. The aim was to evaluate the possibility of harvesting retained seeds on weeds at crop harvest by a combine harvester based on estimation of weeds seed retention. Before flowering, ten plants of each weed species were selected and surrounded by a seed trap comprising of a porous net. When the plants started shedding seeds, the seeds were collected from the traps and counted weekly until crop harvest. Just before crop harvest, the retained seeds on the plants were counted and the ratio of harvestable seeds and shed seeds during the growing season were determined. The seed production and shedding patterns varied between the species. In oat, Anagallis arvensis L., Capsella bursa-pastoris (L.) Medik., Chenopodium album L., Fallopia convolvulus (L.) Á. Löve, Geranium molle L., Persicaria maculosa Gray, Polygonum aviculare L., Silene noctiflora L., Sinapis arvensis L., Sonchus arvensis L., Spergula arvensis L., Stellaria media (L.) Vill.,Veronica persica Poir., and Viola arvensis Murray retained on average 61, 52, 67, 44, 58, 32, 59, 95, 67, 23, 45, 56, 51, and 33%, respectively, of their produced seeds at crop harvest. In wheat, Alopecurus myosuroides Huds. and Apera spica-venti (L.) P. Beauv. retained on average 34 and 33%, respectively, of their seeds at harvest. Silene noctiflora was classified as a good target for harvest weed seed control; A. myosuroides, A. spica-venti, C. bursa-pastoris, C. album, F. convolvulus, G. molle, P.maculosa, Sinapis arvensis, Sonchus arvensis, Spergula arvensis and V. arvensis were classified as intermediate targets; and A. arvensis, P. aviculare, S. media and V. persica were classified as poor targets. The research shows that there is a great potential to reduce the input of weed seeds to the soil seed bank by harvest weed seed control. Keywords: Harvest weed seed control; Soil seed bank ; Weed seed retention
Authors
Joyce Machado Nunes Romeiro Tron Haakon Eid Clara Antón Fernández Annika Kangas Erik TrømborgAbstract
It is expected that European Boreal and Temperate forests will be greatly affected by climate change, causing natural disturbances to increase in frequency and severity. To detangle how, through forest management, we can make forests less vulnerable to the impact of natural disturbances, we need to include the risks of such disturbances in our decision-making tools. The present review investigates: i) how the most important forestry-related natural disturbances are linked to climate change, and ii) different modelling approaches that assess the risks of natural disturbances and their applicability for large-scale forest management planning. Global warming will decrease frozen soil periods, which increases root rot, snow, ice and wind damage, cascading into an increment of bark beetle damage. Central Europe will experience a decrease in precipitation and increase in temperature, which lowers tree defenses against bark beetles and increases root rot infestations. Ice and wet snow damages are expected to increase in Northern Boreal forests, and to reduce in Temperate and Southern Boreal forests. However, lack of snow cover may increase cases of frost-damaged seedlings. The increased temperatures and drought periods, together with a fuel increment from other disturbances, likely enhance wildfire risk, especially for Temperate forests. For the review of European modelling approaches, thirty-nine disturbance models were assessed and categorized according to their required input variables and to the models’ outputs. Probability models are usually common for all disturbance model approaches, however, models that predict disturbance effects seem to be scarce.
Authors
Melissa MagerøyAbstract
No abstract has been registered
Authors
Kateřina Hamouzová Pavlina Košnarová lena Ulber Wiktoria Kaczmarek-Derda Björn Ringselle Dagmar RisselAbstract
No abstract has been registered
Authors
Roger HoltenAbstract
No abstract has been registered
Authors
Wiktoria Kaczmarek-DerdaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Elisa Senger Sonia Osorio Klaus Olbricht Paul Shaw Béatrice Denoyes Jahn Davik Stefano Predieri Saila Karhu Sebastian Raubach Nico Lippi Monika Höfer Helen Cockerton Christophe Pradal Ebru Kafkas Suzanne Litthauer Iraida Amaya Björn Usadel Bruno MezzettiAbstract
No abstract has been registered