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.
1998
Forfattere
Hugh RileySammendrag
A tillage trial was performed on morainic loam soil in south-east Norway over the years 1985-97. Two times of moulboar
Forfattere
Hugh RileySammendrag
The article contains results from seven long-term tillage trials in Norway, 6 on loam and 1 on clay soil. The emphasis of the report is on the ability to maintain crop yields under reduced tillage systems.
Forfattere
Hugh RileySammendrag
Det er ikke registrert sammendrag
1997
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.
Sammendrag
Det er ikke registrert sammendrag
Populærvitenskapelig – Jord- og plantekultur 1997 Korn - Frøavl - Potet - Grønnsaker
Unni Abrahamsen
Forfattere
Unni AbrahamsenSammendrag
Det er ikke registrert sammendrag
1992
Sammendrag
Det er ikke registrert sammendrag