Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2023
Forfattere
Kim Viggo Paulsen Weiby Sophie Julie Krizsan Ingjerd Dønnem Liv Østrem Margrete Eknæs Håvard SteinshamnSammendrag
Mitigating enteric methane (CH4) emissions is crucial as ruminants account for 5% of global greenhouse gas emissions. We hypothesised that less frequent harvesting, use of crops with lower WSC concentration, ensiling at low crop dry matter (DM) and extensive lactic acid fermentation would reduce in vitro CH4 production. Timothy (T), timothy + red clover mixture (T + RC) or perennial ryegrass (RG), cut either two or three times per season, was wilted to 22.5% or 37.5% DM and ensiled with or without formic acid-based additive. Silages were analysed for chemical composition and fermentation products. In vitro CH4 production was measured using an automated gas in vitro system. Methane production was, on average, 2.8 mL/g OM lower in the two-cut system than in the three-cut system (P < 0.001), and 1.9 mL/g OM lower in T than in RG (P < 0.001). Silage DM did not affect CH4 production (P = 0.235), but formic acid increased CH4 production by 1.2 mL/g OM compared to the untreated silage (P = 0.003). In conclusion, less frequent harvesting and extensive silage fermentation reduce in vitro CH4 production, while RG in comparison to T resulted in higher production of CH4.
Forfattere
Ravindu Panditharathne Miyuru Gunathilake Imiya M. Chathuranika Upaka Rathnayake Mukand S. Babel Manoj K. JhaSammendrag
Rainfall is one of the dominating climatic parameters that affect water availability. Trend analysis is of paramount significance to understand the behavior of hydrological and climatic variables over a long timescale. The main aim of the present study was to identify trends and analyze existing linkages between rainfall and streamflow in the Nilwala River Basin (NRB) of Southern Sri Lanka. An investigation of the trends, detection of change points and streamflow alteration, and linkage between rainfall and streamflow were carried out using the Mann–Kendall test, Sen’s slope test, Pettitt’s test, indicators of hydrological alteration (IHA), and Pearson’s correlation test. Selected rainfall-related extreme climatic indices, namely, CDD, CWD, PRCPTOT, R25, and Rx5, were calculated using the RClimdex software. Trend analysis of rainfall data and extreme rainfall indices demonstrated few statistically significant trends at the monthly, seasonal, and annual scales, while streamflow data showed non-significant trends, except for December. Pettitt’s test showed that Dampahala had a higher number of statistically significant change points among the six rainfall stations. The Pearson coefficient correlation showed a strong-to–very-strong positive relationship between rainfall and streamflow. Generally, both rainfall and streamflow showed non-significant trend patterns in the NRB, suggesting that rainfall had a higher impact on streamflow patterns in the basin. The historical trends of extreme climatic indices suggested that the NRB did not experience extreme climates. The results of the present study will provide valuable information for water resource planning, flood and disaster mitigation, agricultural operations planning, and hydropower generation in the NRB.
Sammendrag
Active canopy sensors (ACSs) are great tools for diagnosing crop nitrogen (N) status and grain yield prediction to support precision N management strategies. Different commercial ACSs are available and their performances in crop N status diagnosis and recommendation may vary. The objective of this study was to determine the potential to minimize the differences of two commonly used ACSs (GreenSeeker and Crop Circle ACS-430) in maize (Zea mays L.) N status diagnosis and recommendation with multi-source data fusion and machine learning. The regression model was based on simple regression or machine learning regression including ancillary information of soil properties, weather conditions, and crop management information. Results of simple regression models indicated that Crop Circle ACS-430 with red-edge based vegetation indices performed better than GreenSeeker in estimating N nutrition index (NNI) (R2 = 0.63 vs. 0.50–0.51) and predicting grain yield (R2 = 0.56–0.57 vs. 0.49). The random forest regression (RFR) models using vegetation indices and ancillary data greatly improved the prediction of NNI (R2 = 0.81–0.82) and grain yield (R2 = 0.87–0.89), regardless of the sensor type or the vegetation index used. Using RFR models, moderate degree of accuracy in N status diagnosis was achieved based on either GreenSeeker or Crop Circle ACS-430. In comparison, using simple regression models based on spectral data only, the accuracy was significantly lower. When these two ACSs were used independently, they performed similarly in N fertilizer recommendation (R2 = 0.57–0.60). Hybrid RFR models were established using vegetation indices from both ACSs and ancillary data, which could be used to diagnose maize N status (moderate accuracy) and make side-dress N recommendations (R2 = 0.62–0.67) using any of the two ACSs. It is concluded that the use of multi-source data fusion with machine learning model could improve the accuracy of ACS-based N status diagnosis and recommendation and minimize the performance differences of different active sensors. The results of this research indicated the potential to develop machine learning models using multi-sensor and multi-source data fusion for more universal applications.
Forfattere
Santiago A. Utsumi Shelemia Nyamuryekung'e Andres Perea Maximiliano Spetter Andrew Cox Lara Macon Richard Estell Glenn DuffSammendrag
Virtual fencing is a promising alternative to contain livestock dispersal without using physical barriers. This technology uses smart-wearable collars that deliver predictable warning tones to animals when they approach virtual boundaries paired with mild electric pulses. Virtual fencing allows for dynamic management of livestock grazing, based on site-specific variations in the quality and quantity of forages. However, several factors can affect the efficacy of virtual fencing, including the length of prior experience with virtual fencing, climatic conditions, forage availability inside and outside virtual fencing paddocks and collar configuration schedules. Lactation requirements and social interactions between collared cows and uncollared calves can also influence the efficacy of the technology. Virtual fencing trials were conducted at the New Mexico State University’s Chihuahuan Desert Rangeland Research Center from August 27 to December 21 of 2022 to evaluate the efficacy of virtual fencing to manage rangeland cows during late lactation and following weaning. Twenty-six Brangus cows previously trained to use NoFence C2 collars (NoFence, Batnfjordsøra, Norway), were monitored for 30 days during late lactation and 28 days after weaning. Collared cows and uncollared calf pairs were allocated to four virtual fence pastures in late lactation and after weaning, with pasture duration (4.2 ± 0.6 d), size (72 ± 19 ha) and perimeter (4,523 ± 352 m) varying according to forage availability and access to fresh drinking water. Audio cues, electric pulses and ratio of electric pulses to audio cues before and after weaning were compared by ANOVA in a Completely Randomized Design replicated across pre-weaning and post-weaning pastures (n = 8). The average number of electric pulses per cow was greater (P < 0.0004) for pre-weaning (3.7 ± 0.2) than for post-weaning post-weaning (1.6 ± 0.3) pastures. The number of audio warnings per cow was also greater (P < 0.0001) for pre-weaning (52 ± 3.3) than post-weaning (34 ± 3.3) pastures. Conversely, cows had decreased (P < 0.0001) ratios of electric pulses relative to audio tones on post-weaning (4.8 ± 0.5%) than pre-weaning (7.0 ± 0.8%) pastures. These results suggest that cows responded better to virtual fencing after weaning, likely because weaned cows were no longer affected by social interactions with uncollared calves. Furthermore, cows after weaning apparently relied on warning tones and fewer electric pulses to interact safely with virtual fences. However, it is important to note that sources of variation not accounted for or controlled by the present experimental design may have also affected the recorded interactions with virtual fences in the present study.
Forfattere
Tomás Brůna Rishi Aryal Olga Dudchenko Daniel James Sargent Daniel Mead Matteo Buti Andrea Cavallini Timo Hytönen Javier Andrés Melanie Pham David Weisz Flavia Mascagni Gabriele Usai Lucia Natali Nahla Bassil Gina E. Fernandez Alexandre Lomsadze Mitchell Armour Bode Olukolu Thomas Poorten Caitlin Britton Jahn Davik Hamid Ashrafi Erez Lieberman Aiden Mark Borodovsky Margaret WorthingtonSammendrag
Blackberries (Rubus spp.) are the fourth most economically important berry crop worldwide. Genome assemblies and annotations have been developed for Rubus species in subgenus Idaeobatus, including black raspberry (R. occidentalis), red raspberry (R. idaeus), and R. chingii, but very few genomic resources exist for blackberries and their relatives in subgenus Rubus. Here we present a chromosomelength assembly and annotation of the diploid blackberry germplasm accession “Hillquist” (R. argutus). “Hillquist” is the only known source of primocane-fruiting (annual-fruiting) in tetraploid fresh-market blackberry breeding programs and is represented in the pedigree of many important cultivars worldwide. The “Hillquist” assembly, generated using Pacific Biosciences long reads scaffolded with high-throughput chromosome conformation capture sequencing, consisted of 298Mb, of which 270Mb (90%) was placed on 7 chromosome-length scaffolds with an average length of 38.6Mb. Approximately 52.8% of the genome was composed of repetitive elements. The genome sequence was highly collinear with a novel maternal haplotype-resolved linkage map of the tetraploid blackberry selection A-2551TN and genome assemblies of R. chingii and red raspberry. A total of 38,503 protein-coding genes were predicted, of which 72% were functionally annotated. Eighteen flowering gene homologs within a previously mapped locus aligning to an 11.2Mb region on chromosome Ra02 were identified as potential candidate genes for primocane-fruiting. The utility of the “Hillquist” genome has been demonstrated here by the development of the first genotyping-by-sequencing-based linkage map of tetraploid blackberry and the identification of possible candidate genes for primocane-fruiting. This chromosome-length assembly will facilitate future studies in Rubus biology, genetics, and genomics and strengthen applied breeding programs.
Sammendrag
Weeds affect crop yield and quality due to competition for resources. In order to reduce the risk of yield losses due to weeds, herbicides or non-chemical measures are applied. Weeds, especially creeping perennial species, are generally distributed in patches within arable fields. Hence, instead of applying control measures uniformly, precision weeding or site-specific weed management (SSWM) is highly recommended. Unmanned aerial vehicle (UAV) imaging is known for wide area coverage and flexible operation frequency, making it a potential solution to generate weed maps at a reasonable cost. Efficient weed mapping algorithms need to be developed together with UAV imagery to facilitate SSWM. Different machine learning (ML) approaches have been developed for image-based weed mapping, either classical ML models or the more up-to-date deep learning (DL) models taking full advantage of parallel computation on a GPU (graphics processing unit). Attention-based transformer DL models, which have seen a recent boom, are expected to overtake classical convolutional neural network (CNN) DL models. This inspired us to develop a transformer DL model for segmenting weeds, cereal crops, and ‘other’ in low-resolution RGB UAV imagery (about 33 mm ground sampling distance, g.s.d.) captured after the cereal crop had turned yellow. Images were acquired during three years in 15 fields with three cereal species (Triticum aestivum, Hordeum vulgare, and Avena sativa) and various weed flora dominated by creeping perennials (mainly Cirsium arvense and Elymus repens). The performance of our transformer model, 1Dtransformer, was evaluated through comparison with a classical DL model, 1DCNN, and two classical ML methods, i.e., random forest (RF) and k-nearest neighbor (KNN). The transformer model showed the best performance with an overall accuracy of 98.694% on pixels set aside for validation. It also agreed best and relatively well with ground reference data on total weed coverage, R2 = 0.598. In this study, we showed the outstanding performance and robustness of a 1Dtransformer model for weed mapping based on UAV imagery for the first time. The model can be used to obtain weed maps in cereals fields known to be infested by perennial weeds. These maps can be used as basis for the generation of prescription maps for SSWM, either pre-harvest, post-harvest, or in the next crop, by applying herbicides or non-chemical measures.
Sammendrag
Denne rapporten gir en oversikt over tilstanden i skog som var vernet per. 1.1.2021. Datamaterialet som er utgangspunktet for rapporten er registreringer gjennomført av Landsskogtakseringen, gjennom «Overvåkingsprogrammet for skog i verneområder». Registreringene er utført i løpet av femårsperioden 2017-2021. Utvalgte resultater: • Vernet skog omfattet per 1.1. 2021 totalt 592 481 ha, tilsvarende 4,9 prosent av det totale skogarealet. • 3,7 prosent av den produktive skogen, og 7,9 prosent av den uproduktive skogen i landet finnes i vernet skog, der skogbruk ikke er tillatt. • I produktiv skog er andelen skogareal i klassene middels og høy+ svært høy bonitet underrepresentert samlignet med skogen generelt. • Skogen i verneområder er generelt eldre og har en større andel skog i senere utviklingstrinn. Biologisk gammel skog etter Landsskogtakseringens definisjon utgjør nærmere tre ganger så høy andel i den produktive delen av vernet skogareal som i produktiv skog totalt. • Det stående volumet i verneområdene utgjør 4,1 prosent av totalt stående volum. • Gjennomsnittlig tilvekst i skog som var vernet per 1.1.2016 er lavere enn gjennomsnittet for skog generelt. • Vernet skog inneholder mer volum død ved per hektar i gjennomsnitt enn øvrig skog. • I produktiv skog er MiS-livsmiljøene “liggende dødved” og “stående dødved”, samt “gamle trær” vanligere i verneområdene. For uproduktiv skog er “gamle trær” vanligere. I tillegg presenteres resultater som viser hvordan den vernede skogen har utviklet seg siden forrige taksering, som ble gjennomført 2012-2016.
Sammendrag
Vipe (Vanellus vanellus) har de siste tiårene hatt en sterk nedgang i bestanden. Statsforvalteren i Rogaland innførte tiltaket ‘vipestriper’ i Time kommune i 2019 og for hele fylket i 2020, som del av RMP. Målsetningen for dette prosjektet har vært å evaluere bruk og effekt av vipestriper, og finne ut hvorvidt stripene oppleves som et vellykket tiltak for å ta vare på vipa i jordbrukslandskapet. Vi har gjennomført en spørreundersøkelse og arrangert et folkemøte med gårdbrukere som har etablert vipestriper eller som har vist interesse for disse. Resultatene er basert på svarene til de 40 deltakerne som gjennomførte spørreundersøkelsen, samt samtaler under folkemøtet og tilbakemeldinger via e-post. Vi konkluderer med at vipestriper generelt har en positiv effekt, som varierer noe avhengig av omkringliggende arealer. Vi anbefaler at tiltaket videreføres med følgende hensyn: Vipestriper bør anlegges særlig der fuglene hekker jevnlig, og i nærheten av våte arealer. Vipestriper bør ikke anlegges nærmere enn 50 m fra høye busker og heller ikke på høstsådd areal. Turgåere bør kanaliseres vekk fra vipestriper og andre områder med mye vipe i hekkesesongen.
Forfattere
Martina Paponov Jörg Ziegler Ivan PaponovSammendrag
Light acts as a trigger to enhance the accumulation of secondary compounds in the aboveground part of plants; however, whether a similar triggering effect occurs in roots is unclear. Using an aeroponic setup, we investigated the effect of long term exposure of roots to LED lighting of different wavelengths on the growth andp hytochemical composition of two high-value medicinal plants, Artemisia annua and Hypericum perforatum. In A. annua, root exposure to white, blue, and red light enhanced the accumulation of artemisinin in the shoots by 2.3-, 2.5-, and 1.9-fold, respectively. In H. perforatum, root exposure to white, blue, red, and green light enhanced the accumulation of coumaroylquinic acid in leaves by 89, 65, 84, and 74%, respectively. Root lighting also increased flavonol concentrations. In contrast to its effects in the shoots, root illumination did not change phytochemical composition in the roots or root exudates. Thus, root illumination induces a systemic response, resulting in modulation of the phytochemical composition in distal tissues remote from the light exposure site.
Redaktører
Giuseppe E. Scarascia-Mugnozza Vicente Guallart Fabio Salbitano Giovanna Ottaviani Aalmo Stefano BoeriSammendrag
This edited volume centers around the concept of BioCities, which aim to unify nature and urban spaces in order to reverse the effects of global climate change and inequity. Following this principle, the authors propose multiple approaches for sustainable city growth. The discussed concepts are not only relevant for newly constructed cities, but offer transformative perspectives for existing settlements as well. Placing nature at the forefront of city planning is not an entirely new concept, so the authors build on established ideas like the garden city, green city, eco-city, or smart city. All chapters aim to highlight aspects to develop a city that is a resilient nature-based socio-ecological system. Many of these concepts were formed in an effort to copy the best traits of a forest ecosystem: a home for many different species that build complex communities. Much like many of our forests, urban areas are managed by humans for multifunctional purposes, using living and abiotic components. This viewpoint helps to understand the potential and limitations of sustainable growth. With these chapters, the authors want to inspire planners, ecologists, urban foresters and decision makers of the future.