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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.

2019

Abstract

In the past decade, China imported massive quantities of soybean from the international market to meet its increasing domestic demand for protein[1]. However, China’s soybean imports from US decreased from 32.86 Mt (Million tons, 34% of the total 95.54 Mt) in 2017 to 16.64 Mt (19% of the total 88.03 Mt) in 2018[2] due to the China-US trade war. To reduce China’s reliance on imports, the Chinese government has been making policy incentive, e.g. higher subsidies, to encourage farmers for soybean cultivation. Traditionally Northeast China is the key production area for soybean. Soybean cultivation is tightly linked to the regional climate and environment. On the one hand, the local soybean growth is vulnerable[3] to the frequent meteorological hazards (e.g. droughts, floods) in the Northeast China[4]. The meteorological risks for soybean production in this area still remain unknown. On the other hand, albeit with relatively high production cost[5] and low water use efficiency[6], the local soybean cultivation is expected to effectively improve the nitrogen use efficiency and therefore alleviate the growing environment pollutions in this region[7]. Yet so far there are few quantitative research being reported on this environmental issue. Our research aims to explore both the meteorological risks and environmental costs of the policy-driven soybean expansion. We have developed a new version of the soybean growth algorithms within the DNDC (DeNitrification-DeComposition) model including nitrogen biogeochemical processes and performed regional simulations for soybean-related cropping systems in Northeast China. We will present the following results by combining model outputs and observations: (i) potential yield and the meteorological risks of soybean cultivation; (ii) fertilizer reduction in different crop rotation systems and the corresponding benefits to water ecosystem; and (iii) consequences of different policy scenarios (e.g. change in subsidy, GMO permission) to soybean production and environment.

To document

Abstract

Pastures are botanically diverse and difficult to characterize. Digital modeling of pasture biomass and quality by non-destructive methods can provide highly valuable support for decision-making. This study aimed to evaluate aerial and on-ground methods to characterize grass ley fields, estimating plant height, biomass and volume, using digital grass models. Two fields were sampled, one timothy-dominant and the other ryegrass-dominant. Both sensing systems allowed estimation of biomass, volume and plant height, which were compared with ground truth, also taking into consideration basic economical aspects. To obtain ground-truth data for validation, 10 plots of 1 m2 were manually and destructively sampled on each field. The studied systems differed in data resolution, thus in estimation capability. There was a reasonably good agreement between the UAV-based, the RGB-D-based estimates and the manual height measurements on both fields. RGB-D-based estimation correlated well with ground truth of plant height (R 2 > 0.80) for both fields, and with dry biomass (R 2 = 0.88), only for the timothy field. RGB-D-based estimation of plant volume for ryegrass showed a high agreement (R 2 = 0.87). The UAV-based system showed a weaker estimation capability for plant height and dry biomass (R 2 < 0.6). UAV-systems are more affordable, easier to operate and can cover a larger surface. On-ground techniques with RGB-D cameras can produce highly detailed models, but with more variable results than UAV-based models. On-ground RGB-D data can be effectively analysed with open source software, which is a cost reduction advantage, compared with aerial image analysis. Since the resolution for agricultural operations does not need fine identification the end-details of the grass plants, the use of aerial platforms could result a better option in grasslands.

To document

Abstract

This study aimed at identifying optimal sward conditions for successful establishment of red clover (Trifolium pratense L.) through sod-seeding two typical Norwegian grassland systems dominated by timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.), respectively. A total of four sod-seeding trials were implemented, two in late summer (SUM) and two in spring (SPR), one for each sward type and time point for reseeding. The sward coverage status was the basis for threshold definition, and image analysis techniques were used for objective coverage estimation of living plants, dead material and bare soil. Plots with different coverage levels (0–100% of the soil covered by vegetation) were created by spraying a broad-spectrum herbicide (glyphosate) in a spot-wise pattern, mimicking common types of patchiness caused by stressful weather events, e.g., frost or mechanical damage from wheels or hoofs. Seed germination and emergence started similarly in all coverage ranges. However, as time progressed clover seedlings started to die at a coverage dependent rate, and at the final harvest red clover dry matter (RCDM) was the lowest on plots with the highest pre-seeding coverage level. Dose-response curves explained these relationships and allowed estimating the effective-coverage ( ECov80 ), being the initial sward coverage at which 80% of all established red clover plants contributed significantly to the total biomass. Above 2500 kg ha−1 RCDM were produced on timothy ( ECov80 : 15–50%) in SUM, while less than 1000 kg ha−1 RCDM were produced on ryegrass ( ECov80:±10% ), indicating better conditions for clover establishment in timothy compared with ryegrass. In SPR, an ECov80 : 10–15% allowed a good red clover estabishment in ryegrass at cut 3, while RCDM was important and significant in timothy even between ECov80 20 and 60%, at cut 2 and cut 3, respectively. These thresholds for sod-seeding mark the challenges to introduce red clover in dense swards and could be applicable for grassland renovation with other desirable legume and grasses species. Our findings represent particular soil and climatic characteristics of the study site, thus should be taken with caution. Due to the lack of experimentally and sytematically determined thresholds for reseeding, future studies could benefit from our experimental approach, as a base for more complex, multi-site and multi-seasonal investigations, and farmers could use these thresholds for decision making on successful grassland renovation, to avoid wasting seed resources and yield loses.

To document See dataset

Abstract

There is a large potential in Europe for valorization in the vegetable food supply chain. For example, there is occasionally overproduction of tomatoes for fresh consumption, and a fraction of the production is unsuited for fresh consumption sale (unacceptable color, shape, maturity, lesions, etc.). In countries where the facilities and infrastructure for tomato processing is lacking, these tomatoes are normally destroyed, used as landfilling or animal feed, and represent an economic loss for producers and negative environmental impact. Likewise, there is also a potential in the tomato processing industry to valorize side streams and reduce waste. The present paper provides an overview of tomato production in Europe and the strategies employed for processing and valorization of tomato side streams and waste fractions. Special emphasis is put on the four tomato-producing countries Norway, Belgium, Poland, and Turkey. These countries are very different regards for example their climatic preconditions for tomato production and volumes produced, and represent the extremes among European tomato producing countries. Postharvest treatments and applications for optimized harvest time and improved storage for premium raw material quality are discussed, as well as novel, sustainable processing technologies for minimum waste and side stream valorization. Preservation and enrichment of lycopene, the primary health promoting agent and sales argument, is reviewed in detail. The European volume of tomato postharvest wastage is estimated at >3 million metric tons per year. Together, the optimization of harvesting time and preprocessing storage conditions and sustainable food processing technologies, coupled with stabilization and valorization of processing by-products and side streams, can significantly contribute to the valorization of this underutilized biomass.

Abstract

Rhodiola rosea is a highly valued herbal medicinal plant. It is growing wild in most parts of Norway and mountainous areas around the world. The marker compounds are salidroside, cinnamyl alcohol, glycosides (rosine, rosavine, rosarine), flavonoids (rhodionin, rhodiosin, rhodiolin) and terpens (Galambosi 1999), where the rosavins are unique to R. rosea. In Norway, germplasm collections of R. rosea are maintained by NIBIO; at Apelsvoll in Southern Norway, consisting of 97 different clones. The ranges in content of secondary metabolites in the collection are for rosavin 2.90-85.95 mg g-1, salidroside 0.03-12.85 mg g-1, rosin 0.08-4.75 mg g-1, tyrosol 0.04-2.15 mg g-1 and cinnamyl alcohol 0.02-1.18 mg g-1. A number of different studies have been performed on how biotic and abiotic factors affects the yield of the roots as well the content in metabolites. We find that the flowering of the plant is dependent on cool temperatures during dormancy and thus climatic changes may affect the plant development as well as the production of metabolites. Studies performed in Norway as well as between European countries shows that geographical location affects the content of metabolites and here also variation in clones are a player. In the present presentation results from these and more studies will be presented. Also comprising results on the effect of white-, blue- and red light on the growth and chemical composition of greenhouse grown plants.