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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

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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.

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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.

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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.