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.
1997
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Jorunn Elisabeth Olsen Olavi Junttila Jarle Nilsen M. E. Eriksson Inger Martinussen Olaf Olsson Göran Sandberg Thomas MoritzSammendrag
Resultatene i arbeidet indikerer at den fotoperiodiske responsen hos tre kan være regulert av mengde PHYA genuttrykk, og at mengden av fytokrom A påvirker metabolismen av GAs (gibberelliner) og IAA (auxin).
Forfattere
K. FurubergSammendrag
Det er ikke registrert sammendrag
Forfattere
Hugh RileySammendrag
Det er ikke registrert sammendrag
Forfattere
Hugh RileySammendrag
The biproduct (algal fibre) which remains after alginate extraction from seaweed contains substantial amounts of plant nutrients, including nitrogen, potassium, sulphur and some phosphorus as well as bases such as sodium, magnesium and calcium. It also contains perlite, which is used to filter out the fibre material. This gives the biproduct a high potential as a physical soil ameliorant, as demonstrated in earlier studies. This study investigated the effects of applying algal fibre at rates of 20 and 40 tonnes DM/ha in spring, on the yield and quality of potatoes and on the nutrient status of the soil at the end of the growing season. Treatments with the use of zero, half-normal and normal rates of mineral compound fertilizer were included on subplots, in order to estimate the fibre"s comparative fertilizer value. The soil used was a relatively fertile gravelly loam, with extremely low moisture holding capacity. The trial was irrigated regularly in dry periods. The weather conditions were characterised by an extremely wet spring, followed by warmer and drier conditions than normal during the remainder of the growing season. The algal fibre had a large, positive effect on the yield of potatoes. In the absence of mineral fertilizer, this amounted to increases in total tuber yield of 30% and 70% with the use of 20 and 40 tonnes DM/ha, respectively.The responses were smaller when mineral fertilizer was used, declining to 7% and 17% at the highest fertilizer level. This suggests that the effect of algal fibre was mainly due to improved nutrient supply. The yield of potatoes of a size suitable for table use (>45 mm) was especially favoured. Assuming that the effect of algal fibre was attributable mainly to its supply of nitrogen, its fertilizer value per tonne of dry matter may be interpolated as being equivalent to the use of 2-2.5 kg N in compound fertiliser. This suggests that about 20% of the nitrogen contained in the algal fibre had become available during the first growing season. Algal fibre had a positive effect on tuber DM concentration when used alone, but had a negative effect when used in conjunction with a high level of mineral fertilizer. The latter effect may be attributed to a delay in maturation due to over-optimum nutrient supply. Despite its high base content, the algal fibre had no effect on the level of the skin disorder "common scab", which is normally associated with high soil pH on light soils. Mineral fertilization, on the other hand, gave an unexpected reduction in its occurrence. The use of algal fibre considerably increased nitrogen concentrations in both haulm and tubers. Effects on other mineral contents were mostly negligible, with the exception of sodium concentration. The latter increased markedly, but this was not thought to reduce their eating quality. Soil reserves of plant-available phosphorus, potassium and calcium at harvest were not affected by the use of algal fibre, whereas that of magnesium increased slightly and that of sodium rose sharply. This led to increased electrical conductivity in the soil. The values measured were nevertheless well below the limit at which plant growth is likely to be impaired. Soil pH increased significantly, by about 0.015 units per tonne DM/ha used. Residual levels of mineralised nitrogen in the soil were increased by both algal fibre and mineral fertilizer. When no fertiizer had been used, the use of 40 tonnes DM/ha of fibre gave an increase of 35 kg N/ha in the topsoil at harvest. When the normal level of mineral fertilizer was used in addition, the figure rose to 66 kg/ha. Such reserves may be utilized by following crops if these are established soon afterwards, but may otherwise be lost through leaching during the winter.
Forfattere
Toril Drabløs Eldhuset Per Holm NygaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor MykingSammendrag
Det er ikke registrert sammendrag
Forfattere
Atle Hindar Petter Nilsen A. Skiple R. HøgbergetSammendrag
Det er ikke registrert sammendrag
Sammendrag
We compared diversity of birds in 35 study plots of equal size (58 ha) and productivity in western Norway, ranging from pure native pine Pinus sylvestris forests (n = 7), through different mosaics of native pine forests and spruce Picea spp. plantations (n = 21), to pure spruce plantations (n = 7). Diversity was evaluated by means of species richness, diversity indices, relative abundance curves and rarefaction. The diversity indices appeared to be less suitable for our purpose. Species richness was higher in pine forest than in spruce forest. However, a peak in species richness was found in mosaic forest. For pooled samples (408 ha), 11 bird species recorded in pine forest were not found in spruce forest, seven species were found in spruce forest but not in pine forest, and seven species were confined to the medium mosaics of pine and spruce forest (on average 56% pine and 44% spruce). We argue that, when mixing two habitat types A and B, the ratio of these habitats that maximize avian diversity depends on the ratio of species confined to habitat A and B, as well as the number of species favoured by the mixture of A and B. Existing spruce plantations (13% of the area) in native pine forests of western Norway have reduced the diversity of birds locally, but increased the diversity of birds on the landscape and regional scale.
Forfattere
Hans Christian PedersenSammendrag
Det er ikke registrert sammendrag