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.
2018
Sammendrag
The amount of rented farmland in Norway has increased steadily since the 1950s. Concerns have been raised questioning whether farmland is treated less well by tenants compared to landowners. This study aims to investigate how farmers perceive their treatment of rented farmland, which factors impact their decisionmaking related to this and if farmers are concerned about farmland elements that are less important for productivity but mainly of interest for cultural heritage or environmental management reasons. Semi-structured interviews with a group of randomly selected farmers were carried out in an area dominated by intensive agriculture. Independent of, for example, amount of rented land or duration of the rental agreement, all farmers agreed that rented land was treated well. A strong competition for farmland in combination with farmers being dependent on renting land was the most important reason. Results from this study may be transferrable to other farming areas, at least where competition for farmland is comparable. We do suggest, however, that any further research on treatment of rented farmland in Norway should take a regional approach, since national statistics may cover significant regional differences.
Forfattere
Kaishan Song Zhidan Wen Yingxing Shang Hong Yang Lili Lyu Ge Liu Chong Fang Jia Du Ying ZhaoSammendrag
As a major fraction of carbon in inland waters, dissolved organic carbon (DOC) plays a crucial role incarbon cycling on a global scale. However, the quantity of DOC stored in lakes and reservoirs was notclear to date. In an attempt to examine the factors that determine the DOC storage in lakes and reservoirsacross China, we assembled a large database (measured 367 lakes, and meta-analyzed 102 lakes from fivelimnetic regions; measured 144 reservoirs, and meta-analyzed 272 reservoirs from 31 provincial units) ofDOC concentrations and water storages for lakes and reservoirs that are used to determine DOC storagein static inland waters. We found that DOC concentrations in saline waters (Mean/median ± S.D: 50.5/30.0 ± 55.97 mg/L) are much higher than those in fresh waters (8.1/5.9 ± 6.8 mg/L), while lake DOCconcentrations (25.9/11.5 ± 42.04 mg/L) are much higher than those in reservoirs (5.0/3.8 ± 4.5 mg/L). Interms of lake water volume and DOC storage, the Tibet-Qinghai lake region has the largest water volume(552.8 km3), 92% of which is saline waters, thus the largest DOC (13.39 Tg) is stored in these alpine lakeregion; followed by the Mengxin lake region, having a water volume of 99.4 km3in which 1.75 Tg DOCwas stored. Compared to Mengxin lake region, almost the same amount of water was stored in East Chinalake region (91.9 km3), however, much less DOC was stored in this region (0.43 Tg) due to the lower DOCconcentration (Ave: 3.45 ± 2.68 mg/L). According to our investigation, Yungui and Northeast lake regionshad water storages of 32.14 km3and 19.44 km3respectively, but relatively less DOC was stored in Yungui(0.13 Tg) than in Northeast lake region (0.19 Tg). Due to low DOC concentration in reservoirs, especiallythese large reservoirs having lower DOC concentration (V > 1.0 km3: 2.31 ± 1.48 mg/L), only 1.54 Tg wasstored in a 485.1 km3volume of water contained in reservoirs across the entire country.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Inge Stupak Tat Smith Nicholas Clarke Teodorita Al-Seadi Lina Beniušienė Niclas Scott Bentsen Quentin Cheung Virginia Dale Jinke van Dam Rocio Diaz-Chavez Uwe Fritsche Martyn Futter Jianbang Gan Kaija Hakala Thomas Horschig Martin Junginger Yoko Kitigawa Brian Kittler Keith Kline Charles Lalonde Søren Larsen Dagnija Lazdina Thuy P. T. Mai-Moulin Maha Mansoor Edmund Mupondwa Shyam Nair Nathaniel Newlands Liviu Nichiforel Marjo Palviainen John Stanturf Kay Schaubach Johanny Arilexis Perez Sierra Vita Tilvikiene Brian Titus Daniela Thrän Sergio Ugarte Liisa Ukonmaanaho Iveta Varnagyrite-Kabasinkiene Maria WellischSammendrag
Det er ikke registrert sammendrag
Forfattere
Volkmar Timmermann Mari Mette Tollefsrud Halvor Solheim Isabella Børja Nina Elisabeth Nagy Ari HietalaSammendrag
Det er ikke registrert sammendrag
Sammendrag
The effect of controlled nutrient feeding during the period of short day (SD) induction of flowering has been studied in three SD berry crops. An experimental system with standardized plant material grown with trickle fertigation in controlled environments was used. In strawberry, flowering was advanced and increased when an additional N pulse was given 1-2 weeks after commencement of a 4-week SD induction period, while the opposite resulted when the treatment was applied 2 weeks before start of SD. In blackcurrant, the highest flowering and yield were obtained when fertilization was applied shortly after the natural photoperiod had declined to the inductive length in September. While generous nutrient supply during spring and summer reduced berry soluble solids in blackcurrant, this was not observed with autumn fertilization. Autumn fertilization did not adversely affect plant winter survival or growth vigour in spring. Withdrawal of fertilization prior to, or at various stages during floral induction, did not significantly affect flowering and yield in raspberry, but marginally advanced flowering and fruit ripening.
Forfattere
Daniel R. Hirmas Daniel Gimenez Attila Nemes Ruth Kerry Nathaniel A. Brunsell Cassandra J. WilsonSammendrag
Soil macroporosity affects field-scale water-cycle processes, such as infiltration, nutrient transport and runoff1,2, that are important for the development of successful global strategies that address challenges of food security, water scarcity, human health and loss of biodiversity3. Macropores—large pores that freely drain water under the influence of gravity—often represent less than 1 per cent of the soil volume, but can contribute more than 70 per cent of the total soil water infiltration4, which greatly magnifies their influence on the regional and global water cycle. Although climate influences the development of macropores through soil-forming processes, the extent and rate of such development and its effect on the water cycle are currently unknown. Here we show that drier climates induce the formation of greater soil macroporosity than do more humid ones, and that such climate-induced changes occur over shorter timescales than have previously been considered—probably years to decades. Furthermore, we find that changes in the effective porosity, a proxy for macroporosity, predicted from mean annual precipitation at the end of the century would result in changes in saturated soil hydraulic conductivity ranging from −55 to 34 per cent for five physiographic regions in the USA. Our results indicate that soil macroporosity may be altered rapidly in response to climate change and that associated continental-scale changes in soil hydraulic properties may set up unexplored feedbacks between climate and the land surface and thus intensify the water cycle.
Forfattere
Katharina Strobl Claudia Schmidt Johannes KollmannSammendrag
Phytometers are indicator transplants that provide information on site conditions based on plant survival,growth and reproduction. Since this is a relatively new approach, standards for its implementation remain to bedefined, for example, during peatland restoration. Peatland restoration frequently aims at recovering char-acteristic communities, and a key attribute of successfully restored ecosystems is their capacity to sustain viablepopulations of target species. When not actively introduced, these species are expected to establish on their ownafter improving site conditions, for example by rewetting. Assessments to determine whether this goal is metrequire the long-term monitoring of species’ presence, whereas the underlying causes of these observations, i.e.site or dispersal limitation, often remain unknown. Using phytometers within ecological restoration helps ad-dressing this question. The goal of this study is to compare the responses of several species and traits to en-vironmental conditions in restored peatlands. Three target species (Drosera rotundifolia, Eriophorum vaginatum,Vaccinium oxycoccos) were planted in restored montane peatlands in central Germany, while in a greenhouseexperiment, the same species were grown on peat from the field sites and exposed to two water levels. Severalplant traits were measured and compared with variation in light, water and soil conditions. The response tohabitat conditions was species-specific, indicating that the use of different phytometers increases the reliabilityof monitoring. Survival and growth traits were suitable to assess a wide range of abiotic conditions, whiledifferences in reproductive output were more time-consuming to measure. Survival provided the most conclusiveresults for species sensitive to stressful habitat conditions. Biomass and other size metrics of the phytometers, aswell as growth and reproductive traits were partly redundant. Thus, we suggest recording survival and biomassand use non-destructive growth measurements for repeated assessments, while the choice of the most suitablesize trait should depend on the growth form. Our study stresses the potential of phytometers for monitoring therestoration outcome, while highlighting the importance of species and trait selection.
Forfattere
Zelalem Bekeko Chemeda Fininsa Shimelis Hussien Temam Hussien Dagne Wegari Belachew Asalf TadesseSammendrag
Fourteen advanced maize inbred lines and locally adapted hybrid maize (BH-540) as a check were used to investigate their reaction to GLS disease. Field experiments were conducted at Bako National Maize Research Centre in 2015 and 2016 main plan ng seasons arranged in a randomized complete block design (RCBD) with three replications. Artificial inoculation with Cercospora zeae-maydis was conducted by applying dry, ground, infected maize leaves into the whorls of younger maize plants. Data on agronomic and disease parameters (latent period, disease severity, disease incidence and lesion type) were recorded from the middle two rows. From the combined analysis of variance, maize genotypes showed significant differences with reaction to GLS indicating the existence of genetic variability among the selected genotypes. Highly significant differences were also observed among entries for all agronomic parameters in both seasons. Gray leaf spot incidence and severity varied among genotypes and between years. The mean GLS incidence and severity were higher in 2016 than 2015. GLS disease incidence in two years ranged from 35% on Sc22 to 95% on CML-387 and severity ranged from 15% on A-7016 to 75% on CKL05003. Significant differences in epidemic variability were also observed among genotypes and seasons. From the analysis of disease progress curves Logistic model (R2=94.55) better described the disease progress curves than the Gompertz model (R2=91.50). Parents; P6 and P8 had the most desirable quality for the most of agronomic traits whereas P2, P7 and P9 were the best parents for grain yield. Among all inbred lines, P6, P7 and P14 were iden fied as the most desirable sources of genes for GLS disease resistance. But P6, P7, P8 and P14 were iden fied as the best genotypes in yield, yield related traits and GLS disease parameters. Thus, these parents were recommended to be used in breeding programs with a purpose of developing high yielder and GLS disease resistant open pollinated varieties. In conclusion this study identified potential and promising high yielding and GLS resistant open pollinated genotypes (CKL05017-B-B, CML-395, CML-387, A-7016, Gu o and Sc22). Therefore, it is recommended that these OPVs can be used by resource poor farmers for direct production where this disease is the most prevalent and/or for further breeding programs in generating novel hybrids for future use.
Forfattere
Monika Suškevičs Sebastian Eiter Stanislav Martinat Dina Stober Elis Vollmer Cheryl L. de Boer Matthias BucheckerSammendrag
Det er ikke registrert sammendrag