Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Authors
Inger MartinussenAbstract
No abstract has been registered
Authors
Inger MartinussenAbstract
No abstract has been registered
Authors
Grete H. M. JørgensenAbstract
No abstract has been registered
Authors
Grete Helen Meisfjord Jørgensen Knut Egil BøeAbstract
No abstract has been registered
Abstract
In Norway, most lambs are slaughtered at the end of the grazing season in September. An increased demand for fresh meat during the off-season may change this pattern. Castration of male lambs is not permitted, and off-season slaughtering may affect the acceptability of the meat. The objective of this study was to determine the effect of gender on meat quality from Norwegian White Sheep lambs slaughtered in September at the age of five months. Twenty-nine male lambs and 46 female lambs were included in the experiment. Loin samples of M. Longissimus dorsi were analysed for sensory profile. Meat from male lambs had higher scores for the less pleasant sensory attributes of cloying (P < 0.05) and rancid (P = 0.08) flavour, and lower scores for the more pleasant attributes of sour and sweet taste (P < 0.05 for both attributes) compared to meat from female lambs. The differences were more apparent between lambs grazing ryegrass than between lambs fed a concentrate and roughage diet. It is concluded that even at the normal slaughtering time in September, significant differences between genders may occur.
Abstract
Abstract: This paper reviews several studies of earthworms in agricultural soils in Norway. Crops and management significantly influence the earthworm fauna. Beneficial impacts of earthworms on plant growth are likely, but challenging to prove. Earthworm casts contain high amounts of extractable plant nutrients, which probably contribute to plant nutrient uptake. Geophagous (soil-eating) species such as Aporrectodea caliginosa and A.rosea dominate the earthworm fauna in our arable soils1. Lumbricus terrestris is also present and was found also in all-arable crop rotations with annual ploughing2. In southern Norway, L. rubellus and A. longa are also common. Earthworm populations, recorded in autumn, vary between 30 and 350 individuals m-2, with the lowest values found in all-arable systems2. The inclusion of leys in the crop rotation increases the abundance of channels, earthworm numbers and their biomass2. Since most earthworms prefer living in the upper soil layer, shallow ploughing (15 cm depth) might be expected to be detrimental. However we found that the number and biomass of earthworms was not lower with shallow than with deep ploughing (25 cm)1. In a study, green manure management affected the biomass, species and number of earthworms3. More worms were found in plots where the green manure was left on the field, compared with where it was removed. L. rubellus responded positively and rapidly to mulching, and so did A.caliginosa in clay soil. The use of biogas slurry from green manure in one season gave no effect on number and biomass of earthworms3. Long-term use of solid animal manure positively influenced some earthworm parameters, even three years after the last application1, compared to mineral fertilizer. Utilizing animal manure to produce biogas may reduce fossil fuel usage and emissions of greenhouse gases. However, there is limited information on how the recycling of digested manure as a fertilizer affects soil fertility in the long run. Reduced recycling of carbon to the soil, may harm soil fauna, including earthworms. In a newly started project on the organic research farm at Tingvoll, Norway, anaerobically digested manure is compared with undigested slurry in perennial ley and arable crops. Effects on crop yields, soil fauna, microbial communities, soil structure, organic matter and nutrient concentrations are being measured. Initial studies showed that several earthworm species were present (A.caliginosa, A.rosea, L.terrestris, L.rubellus, Octolasion cyaneum). Earthworm casts (excrements) from the detritivorous species L. terrestris (that feeds on plant residues) have been shown to be richer in nutrients than bulk soil, but little was known previously about the casts of geophagous species (that ingest mostly soil). Casts from two soil depths (13 and 25 cm) were collected by means of litter bags, to study whether such casts also contained more plant available nutrients than the bulk soil. A.caliginosa and A.rosea were the dominant species in these fields. The casts had considerably higher concentrations of plant nutrients than the bulk soil. The content of total-N was 28 % higher in casts, total-C was 37% higher, the contents of available P and K were 40-60%, whilst those of Ca and Mg were 10-20 % higher. On average for the two sites, these differences corresponded to the following amounts (kg ha-1 y-1): 5.6 for P, 8.9 for K, 5.3 for Mg, 144 for N and 2542 for C. With earthworm densities such as those found in farming systems incl. ley and animal manure (ca. 230 individuals m-2), about 220 tonnes of topsoil per hectare passes through the earthworm digestive tract each year. Our study indicated that earthworm casts are valuable sources of plant nutrients even in soils where the fauna is dominated by geophagous species.
Authors
Erik J. JonerAbstract
No abstract has been registered
Authors
Reidun Pommeresche Anne-Kristin LøesAbstract
Abstract: Little is known about Collembola in arable soil, at least in Norway. Recently, a study includ. this group has been initiated in a Norwegian field experiment (Soileffects). Collembola (springtails) are a group of small animals (1-3 mm) living in vegetation, litter and in the pores and caves in the soil to a depth of ca 15 cm. They are important decomposers of dead plant material, eating fungi, algae and microorganisms in soil and on organic debris. Their grazing and decomposing activity contribute significantly to the nutrient circulation in the soil. The name springtail refers to a furca on their back, usually folded in under the body, but released in need of a rapid escape. In one jump, Collembola can jump more than 50 times their own body length. In Norway 334 species are known; in the world more than 6000. Two main groups are found: Entomobryomorpha; species with a clearly elongated segmented body and Symphyleona; species with a more or less globular body with fused segments, reminding of small “rabbits”. Whereas species living in the vegetation and in the upper soil litter are often pigmented, have long antennas, large furca and visible eyes, soil living species are smaller (< 0.5 mm), and have shorter extremities and lack eyes or have small eyespot. They are often white or grey in color. The general distribution of species in Norway is well studied by Arne Fjellberg1. European papers about Collembola in agricultural soil are available23, but not too much is known about this group of animals in arable soil. On the organic research farm in Tingvoll, NW Norway, an experiment was established in 2011 to compare anaerobically digested manure with undigested slurry in perennial ley and arable crops. Effects on crop yields, soil fauna, microbial communities, soil structure, organic matter and nutrient concentration are recorded. There is limited information on how the manure digestion impacts soil fertility in the long run. A reduced supply of carbon to the soil may impact the soil fauna, which is dependent on this source of energy, because almost none of them produce organic matter themselves. In addition to earthworms, Collembola are studied in this project, called “Soileffects”. Collembola were sampled from 12 plots in the ley part of the Soileffects experimental trail in April 2011. This, to get a start characterization of the fauna. We used small metal rings (5,8 cm in diam, 3,8 cm high) to take out soil cores. The fauna in the samples were extracted by using a variant of Tullgren funnels, where drying the soil force the Collembola out. In cooperation with Arne Fjellberg, we found 250 collembolas and identified them to 17 species, comprising a large variation in colors and body forms. A mean of 21 individuals in each sample, gave an estimate of 7980 individuals m-2 in our ley field. We found species belonging to the Entomobryomorpha and species belonging to the Symphyleona. A numerous species was Isotomurus graminis, with a greenish color, medium long antenna and a solid furca. Isotoma viridis, also greenish, but with purple edges of each segment. In this species, the body hairs are better preserved in alcohol, than mostly found for I. graminis. Of the small, white soil living species, Protaphorura armata, Stenaphorura lubbocki and Mesaphorura macrochaeta were the most numerous species. Possible effects of 3 years manure application with anaerobically digested manure and non-digested manure (slurry) will be measured in 2013. 1 Fjellberg. 1998 and 2007. The Collembola of Fennoscandia and Denmark. Part I and II. Fauna Entoml. Scand. 2 Bardgett and Cook. 1998. Functional aspects of soil animal diversity in agricultural grasslands. Appl. Soil Ecol. 3 Gutierrez-Lopez et al.2011. Movement response of Collemb. to the excreta of two earthw….Soil Biol. Biochem.
Authors
Christian Uhlig Christian Guido BrucknerAbstract
No abstract has been registered
Abstract
No abstract has been registered