Do different agronomic soil tests identify similar nutrient deficiencies?

Traditionally, locally calibrated soil tests were used for fertilizer and lime recommendations. Farmers and advisors are increasingly using new ‘universal’ soil tests without local calibration. The objective of this study was to compare five commercially available soil tests and to determine whether they would provide similar recommendations. In total, 24 fields in Western Finland were sampled for 4 years while being treated with fertilizers, lime and manure. The soil samples were analysed with Mehlich-3, ammonium acetate, H3A, hydrochloric acid and mild acetic acid (Spurway) extractants. In addition, Soil Health Tool (CO₂ burst, water-soluble C and N) and tissue testing were conducted. The different tests extracted different orders of magnitude of nutrients (especially P and Mg), but the results from the different extractions were correlated. Mehlich-3 degree of phosphorus saturation (DPS) presented a threshold, below which soluble phosphorus was not detected. Similar thresholds were found for P, S and Mg. Mehlich-3 and ammonium acetate provided similar results for Ca, Mg and K and can be used interchangeably for liming recommendations. Mehlich-3 identified more fields with Zn, Cu, B and S deficiencies and less fields with Mn deficiencies compared with ammonium acetate + EDTA and tissue testing. The tests had strong correlation, but the determination of nutrient deficiencies needs local calibration of deficiency limits.     

The cultural model of “the good farmer” and the environmental question in Finland

Farmers' relationship with nature isdetermined by the significance of agriculturefor human beings. When agriculture is definedas human activity that uses renewable naturalresources and aims to produce usable food andfiber products, agriculture is explicitlydefined as production. Farmers' relationshipwith nature is based on the principle ofproduction. This article discusses thecontradiction between the peasant values ofprotection of nature that many farmers inFinland still have and the environmental harmtheir production-oriented farming style causes.When farmers interpret their farming practicesas harmonious co-operation with nature, it isdifficult for them to see the polluting effectsof their work. Paul B. Thompson's suggestionthat three religious–philosophical doctrines(hard work, the doctrine of grace, and the mythof garden) have made it easy for farmers toadopt productionist farming strategy is used asa framework to interpret farmers' narrativesconcerning their relationship with nature. Theresearch is qualitative and biographical. Thedata include life stories and biographicaltexts farmers wrote for a competition in1997.     

The Applicability of Needle Chemistry for Diagnosing Heavy Metal Toxicity to Trees

Water, Air, &; Soil Pollution - To estimate the validity of needle chemistry as a tool for diagnosing heavy metal toxicity, we collected needle samples from mature pines and young seedlings and...     

Do same-aged but different height Norway spruce (Picea abies) clones affect soil microbial community?

The influence of individual trees in monocrop forests on soil microbial communities is poorly understood. We measured basal respiration, substrate-induced respiration and phospholipid fatty acids (PLFA), bacterial growth rate with the ³H-thymidine incorporation technique and fungal growth rate as ¹⁴C-acetate incorporation into ergosterol to investigate whether slow- and fast-growing 12-year-old Norway spruce (Picea abies) clones have affected differently on their associated soil microbial communities. Understorey vegetation, soil chemical properties and elemental concentrations of needles were also determined. The slow- and fast-growing spruce clones differed in PLFA profiles, understorey vegetation and elemental concentrations in needles suggesting that spruce clones have directly or indirectly affected soil microbes.     

The first detection of influenza in the Finnish pig population: a retrospective study

Background

Swine influenza is an infectious acute respiratory disease of pigs caused by influenza A virus. We investigated the time of entry of swine influenza into the Finnish pig population. We also describe the molecular detection of two types of influenza A (H1N1) viruses in porcine samples submitted in 2009 and 2010.This retrospective study was based on three categories of samples: blood samples collected for disease monitoring from pigs at major slaughterhouses from 2007 to 2009; blood samples from pigs in farms with a special health status taken in 2008 and 2009; and diagnostic blood samples from pigs in farms with clinical signs of respiratory disease in 2008 and 2009. The blood samples were tested for influenza A antibodies with an antibody ELISA. Positive samples were further analyzed for H1N1, H3N2, and H1N2 antibodies with a hemagglutination inhibition test. Diagnostic samples for virus detection were subjected to influenza A M-gene-specific real-time RT-PCR and to pandemic influenza A H1N1-specific real-time RT-PCR. Positive samples were further analyzed with RT-PCRs designed for this purpose, and the PCR products were sequenced and sequences analyzed phylogenetically.

Results

In the blood samples from pigs in special health class farms producing replacement animals and in diagnostic blood samples, the first serologically positive samples originated from the period July–August 2008. In samples collected for disease monitoring, < 0.1%, 0% and 16% were positive for antibodies against influenza A H1N1 in the HI test in 2007, 2008, and 2009, respectively. Swine influenza A virus of avian-like H1N1 was first detected in diagnostic samples in February 2009. In 2009 and 2010, the avian-like H1N1 virus was detected on 12 and two farms, respectively. The pandemic H1N1 virus (A(H1N1)pdm09) was detected on one pig farm in 2009 and on two farms in 2010.

Conclusions

Based on our study, swine influenza of avian-like H1N1 virus was introduced into the Finnish pig population in 2008 and A(H1N1)pdm09 virus in 2009. The source of avian-like H1N1 infection could not be determined. Cases of pandemic H1N1 in pigs coincided with the period when the A(H1N1)pdm09 virus was spread in humans in Finland.     

Duration of vegetative and generative development phases in oat cultivars released since 1921

Genetic yield improvements in oat (Avena sativa L.) cultivars grown at high latitudes have resulted from marked changes in harvest index and yield components. This study was designed to investigate whether such changes have entailed alterations in duration of different developmental phases: vegetative, generative and grain filling phases and pre-anthesis generative sub-phases such as pre-fertile, pre-abortion, fertile pre-abortion, fertile and abortion sub-phases. We tested 14 oat cultivars released between 1921 and 1988 and 6 breeding lines. Ten randomly sampled plants of each oat entry were collected every 3–4 d (18 times) from seedling emergence until pollination, and apical developmental stages were determined on the most advanced spikelet. Cumulated degree-days (Cdd) for each critical developmental stage and component phases were determined (5 °C as a base temperature). At each measurement the number of leaves, green leaves and tillers on main shoot, apex length (mm) and height to the uppermost node, and stipule (cm) were recorded. Phyllochron (°C d leaf⁻¹) and relative elongation rates (RER) for height characterising traits were calculated. Grain filling was the only period altered by breeding, while no consistent effects on duration of vegetative and generative pre-anthesis phases and sub-phases were detected. Different developmental phases were interrelated: in some cases cultivars with similar duration of pre-anthesis phase, however, differed in duration of some pre-anthesis sub-phases. Their duration was not, however, consistently associated with measured growth and yield parameters. Likely long days that make the northern growing conditions exceptional and unique, substantially narrowed the differences among oat entries in duration of different developmental phases, thereby making their role also less critical in yield determination contrary to the situation in the main global temperate cereal production regions.     

The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature

Abstract

In grassland areas where herbage production has no economic value, the cut grass is often left on the sward surface where its decomposition is influenced by weather conditions. Although the influence of temperature and humidity on decomposition has been investigated under controlled lab conditions, experimentation has generally been under ideal moisture conditions that have not tested the combinations of climatic limitations that might occur in the field. The decomposition of mown turfgrass clippings deposited at different times of vegetation period was studied in situ using nylon bags during the first 8 weeks after deposition to investigate the effect of weather conditions (the air temperature, relative humidity, precipitation) on decomposition. Decomposition is the highest in the case of high air humidity and temperature of 10°C. Limiting factors for decomposition at temperatures above 10°C is the air humidity and below 10°C the air temperature. The general tendency was that the rate of decomposition increased with increasing air temperature up to 10°C, but with further increases of air temperature the decomposition rate slowed down. Relative air humidity had a variable impact (at the beginning of the decomposition process (weeks 1–2) the influence was negative, during weeks 3–8 of the decomposition process the effect was positive), and hence had no generalized relationship with decomposition over the studied decomposition period (weeks 1–8). The most significant influence of weather conditions on the decomposition rate was recorded directly after cutting. If the cutting was done during hot weather conditions, the material was drying fast and therefore decomposed slowly. Our results indicate that for fast decomposition of clippings it is important to maintain the freshness of material. Lower decomposition rates occurred during conditions of hot and dry weather, and also cooler (temperature near to 0°C) weather, and can be compensated as soon as favourable weather arrives.