Phosphorus in Finnish soils in the 1900s with particular reference to the acid ammonium acetate soil test

Comprehensive research into phosphorus (P) in soils and crops began in Finland in the early 1900s. The average amount of total P in the ploughed topsoil layer of mineral soils was about two tonnes per hectare in the 1930s, before the abundant use of fertilisers. The main chemical fractions of P in mineral soils were organic matter, primary apatite and secondary complexes of the hydrous oxides of Al and Fe. Of the smaller amounts of P in light peat soils, as much as 80% was present in stable organic compounds. Field experiments showed that the native P reserves of Finnish soils are poorly available to plants, and that P fertilisers are inefficiently utilised because of the strong fixation of applied phosphate in soils. In evaluations before the late 1950s, all simple chemical tests appeared to be rather unreliable indicators of the supply of P from soils to plants, but later research has shown that the results were impaired by errors implicit in the research materials. Some soil test P values (STP)obtained from old samples stored for more than ten years evidently were too high, particularly for organic soils, and many of the soils studied were strongly acidic and therefore biologically less fertile than the chemical P tests indicated. The acid ammonium acetate method (pH 4.65) was introduced in the early 1950s and has since been used in routine soil testing in Finland, not only for P but for all macronutrients except N. In later evaluations of different methods used for estimating the requirement of P fertilisation, the acid ammonium acetate method has proven equal or superior to any other simple chemical method

Changes of yield responses and soil test values in Finnish soils in relation to cumulative phosphorus and potassium balances

Field experiments with five rates of annual P fertilisation were carried out at 24 sites in Finland 1977-1994. A summary of the yield results was calculated on the basis of the amounts of P recommended to cereals according to STP in early 1990s. The effects of repeated K fertilisation were studied at 21 sites in 1977-1994

Estimating bioavailable reserves and potential leaching of soil P by simple chemical tests

The amounts of P extracted with acid ammonium acetate are significantly correlated with the bioavailable P reserves of Finnish soils. Together with clay percentage the simple extraction method is fairly reliable. In routine soil testing clay% can be estimated visually. Additional improvement in accuracy is possible by extraction with a strong acid. Leaching losses of P are also significantly correlated with acetate-extractable soil P, but the concentration of dissolved phosphate at a certain soil test P value varies with other soil properties and increases with decreasing pH

New Colour-Mass to Light Relations: the role of the Asymptotic Giant Branch phase and of interstellar dust

Colour-M/L (mass-to-light) relations are a popular recipe to derive stellar mass in external galaxies. Stellar mass estimates often rely on near infrared (NIR) photometry, considered an optimal tracer since it is little affected by dust and by the "frosting" effect of recent star formation episodes. However, recent literature has highlighted that theoretical estimates of the NIR M/L ratio strongly depend on the modelling of the Asymptotic Giant Branch (AGB) phase. We use the latest Padova isochrones, with detailed modelling of the Thermally Pulsing AGB phase, to update theoretical colour-M/L relations in the optical and NIR and discuss the consequences for the estimated stellar masses in external galaxies. We also discuss the effect of attenuation by interstellar dust on colour-M/L relations in the statistical case of large galaxy samples.Comment: 17 pages, 13 figures. MNRAS in pres

Chinese Taster Lesson: Parts of the Body - Labelling Worksheet

Label the parts of the body. To be used in conjunction with the Chinese Taster Lesson Plan and Powerpoint

Royal Commission into Family Violence: issues paper

The purpose of this issues paper is to provide general guidance to individuals and organisations in making written submissions to the Royal Commission into Family Violence. Introduction The Royal Commission into Family Violence (‘the Royal Commission’) is seeking submissions from anyone directly affected by family violence, from individuals and organisations who have come into contact with people affected by family violence (whether directly working in the family violence sector or not), and from any others whose experiences and ideas may assist the work of the Royal Commission. Examples of individuals who do not work directly in the family violence sector but may wish to make a submission include general practitioners and other health professionals, social workers, disability workers and advocates, teachers and community or religious leaders. The purpose of this issues paper is to provide general guidance to individuals and organisations in making their written submissions. The Royal Commission is also accepting submissions that address its Terms of Reference1 without responding to the particular questions in this issues paper. Written submissions are just one of the ways in which the Royal Commission will gather views and information. It will also be examining more detailed questions through its research, community engagement and public hearing activities. Updates about the Royal Commission’s activities will appear on our website: www.rcfv.com.a

Soklin fosforimalmi fosforilannoitteena

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Humuspitoiset lannoitteet

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Maan vaihtumattoman reservikaliumin merkitys nurmilla

Maan luontaiset kaliumvarat riittävät useiksi vuosiksi hyviin nurmisatoihin paitsi useimmilla savikoilla myös joillakin kiillepitoisilla karkeilla mailla. Toisaalta melko hienotkin maat ovat paikoin aivan kiilteettömiä ja luonnostaan niin vähäkalisia, että kaliumlannoituksen niukentaminen heikentää nurmen kasvua melkein välittömästi. Kaliumin saantia voidaan ennustaa tarkasti ja luotettavasti määrittämällä viljavuustutkimuksessa vaihtuvan kalium lisäksi happoliukoinen reservikalium uudella, kylmään happouuttoon perustuvalla menetelmällä.vokmk

Peltojen viljavuudesta on pidettävä huolta

Väestön kunnollisen ravitsemuksen turvaava ja kestävä maatalous edellyttää teollisesti tuotettujen kasvinravinteiden käyttöä. Säännön vahvistavia poikkeuksia ovat vanhat jokilaaksojen korkeakulttuurit, jotka perustuivat peltojen kasteluun ravinteikkaalla vedellä. Viljavatkin maat menettävät vähitellen kasvuvoimansa, ellei sadoissa poistuvia välttämättömiä kasvutekijöitä korvata.vokmkfmp