10 research outputs found
BIOMECHANICAL AND PHYSIOLOGICAL ASPECTS OF RIFLE SHOOTING IN SIMULATED BIATHLON COMPETITION
In biathlon competition heart rate levels are commonly approximately 93 % of individual maximum heart rate during skiing. During the shooting heart rate level usually decreases to 61-73 % of maximum (Hoffman & Street, 1992). The result of biathlon competition is mostly affected by VO2max and upper body capacity (Rundell & Bacharach, 1995) and shooting performance including shooting time and accuracy (Hoffman, Gilson, Westenburg & Spencer, 1992). Shooting performance is affected by stability of shooting stance and rifle hold, especially in standing shooting (Groslambert, Candau, Hoffman, Bardy, & Rouillon, 1999). Physical loading diminishes shooting performance the more upper body muscles are involved in exercise (Hoffman, et al. 1992; Groslambert, Candau, Gillot & Rouillon, 1996; Groslambert, et al. 1999). Physical exercise and increasing muscle fatigue results poorer control of balance and shooting posture. Balance control agilities of biathlon athletes have been investigated only by Bozsik, Bretz and Kaske (1995), but connection between balance agilities and shooting result have not been established by any research.
The aim of this project was to develop methods for measuring shooting performance in biathlon
Effects of softwood biochars on soil biota in medium-term field experiments in Finland
Biochar soil amendment could be used to sequester carbon, enhance soil fertility and potentially increase crop yields. It can have significant impacts on soil organic carbon levels and physicochemical conditions, which consequently affect soil micro- and macro-biota. It is therefore important to understand how key biological components in the soil such as microbial and earthworm communities response to biochar application in the long-term. This study was conducted in Southern Finland in a fertile Stagnosol and a nutrient deficient Umbrisol, four and five years after biochar amendment, respectively. Biochars were produced from spruce (Picea abies (L.) H.Karst.) and pine (Pinus sylvestris L.), and applied at the rates of 10 and 30 t ha-1, respectively. Earthworms and soil samples for microbial analyses were collected in September 2015. Soil microbial communities were studied by using phospholipid fatty acid profiling and 16S rRNA gene amplicon sequencing. Casts from the sampled earthworms were collected to investigate the consumption of biochar and the potential of earthworm bioturbation to affect biochar distribution. Additionally, greenhouse gas emissions from soil were measured. Biochar and fertilizer treatments or their interaction had no statistically significant effects on the earthworm abundance, community composition or greenhouse gas emissions in either field. Earthworms had ingested biochar as earthworm casts from biochar treated-plots contained significantly more black carbon than those in the control plots, demonstrating that earthworm bioturbation is a potentially important factor in the translocation of applied biochar in the soil profile. Microbial community structure data will be presented in the final presentation.Non peer reviewe
Soil organic carbon and clay content as deciding factors for net nitrogen mineralization and cereal yields in boreal mineral soils
To achieve appropriate yield levels, inherent nitrogen (N) supply and biological N fixation are often complemented by fertilization. To avoid economic losses and negative environmental impacts due to over-application of N fertilizer, estimation of the inherent N supply is critical. We aimed to identify the roles of soil texture and organic matter in N mineralization and yield levels attained in cereal cultivation with or without N fertilization in boreal mineral soils. First, the net N mineralization and soil respiration were measured by laboratory incubation with soil samples varying in clay and organic carbon (C) contents. Secondly, to estimate the inherent soil N supply under field conditions, both unfertilized and fertilized cereal yields were measured in fields on clay soils (clay 30-78%) and coarse-textured soils (clay 0-28%). In clay soils (C 2.5-9.0%), both the net N mineralization and the cereal yields (without and with fertilization) decreased with increasing clay/C ratio. Moreover, in soils with high clay/C ratio, the agronomic N use efficiency (additional yield per kg of fertilizer N) varied considerably, indicating the presence of growth limitations other than N. In coarse-textured soils, the yield increase attained by fertilization increased with increasing organic C. Our results indicate that for clay soils in a cool and humid climate, the higher the clay content, the more organic C is needed to produce reasonable yields and to ensure efficient use of added nutrients without high N losses to the environment. For coarse soils having a rather high mean organic C of 2.3%, the organic C appeared to improve agronomic N use efficiency. For farmers, simple indicators such as the clay/C ratio or the use of non-N-fertilized control plots may be useful for site-specific adjustment of the rates of N fertilization. Highlights We aimed to identify simple indicators of inherent soil N supply applicable at the farm level. In clay soils, the net N mineralization was found to correlate negatively with the clay/C ratio. In coarse-textured soils, agronomic N use efficiency improved with increasing soil organic C. Clay soils with high clay/C ratio are at risk of low yield levels.Peer reviewe
Biohiilen vaikutus lieroihin: välttämistesti ja kenttäkoe karkealla hiedalla:Effects of biochar on earthworms: avoidance test and field trial in a boreal loamy sand
Biohiilen vaikutus lieroihin: välttämistesti ja kenttäkoe karkealla hiedalla:Effects of biochar on earthworms: avoidance test and field trial in a boreal loamy sand
Effects of biochar on earthworms in arable soil:Avoidance test and field trial in boreal loamy sand
Special issue: Environmental benefits and risks of biochar application to soil /
Edited by Surinder Saggar, Marta Camps Arbestain and Jens Leifeld201