Application of chemometric methods in the evaluation of chemical and spectroscopic data on organic matter from Oxisols in sewage sludge applications

Chemometric methods can contribute to soil research by permitting the extraction of more information from the data. The aim of this work was to use Principal Component Analysis to evaluate data obtained through chemical and spectroscopic methods on the changes in the humification process of soil organic matter from two tropical soils after sewage sludge application. In this case, humic acids extracted from Typic Eutrorthox and Typic Haplorthox soils with and without sewage sludge application for 7 consecutive years were studied. The results obtained for all of the samples and methods showed two clusters: samples extracted from the two soil types. These expected results indicated the textural difference between the two soils was more significant than the differences between treatments (control and sewage sludge application) or between depths. In this case, an individual chemometric treatment was made for each type of soil. It was noted that the characterization of the humic acids extracted from soils with and without sewage sludge application after 7 consecutive years using several methods supplies important results about changes in the humification degree of soil organic matter, These important result obtained by Principal Component Analysis justify further research using these methods to characterize the changes in the humic acids extracted from sewage sludge-amended soils. (C) 2009 Elsevier B.V. All rights reserved.

Characterization by Fluorescence of Organic Matter from Oxisols under Sewage Sludge Applications

Sewage sludge from wastewater treatment contains organic matter and plant nutrients that can play an important role in agricultural production and the maintenance of soil fertility, The present study has aimed to evaluate the degree of humification following sewage sludge application of soil organic matter by laser-induced fluorescence and humic acids using ultraviolet-visible fluorescence, and including comparison with Fourier-transform infrared spectroscopy and elemental analysis. Sewage sludge applications to the soil caused a decrease in the degree of humification of the soil organic matter and humic acids for both a Typic Eutrorthox (clayey) soil and a Typic Haplorthox (sandy) soil of around 14 and 27%, respectively. This effect is probably clue to incorporation of newly formed humic substances from the sewage sludge into the characteristics of less humified material, and to the indigenous soil humic substances. The minor alterations observed in the clay soil probably occurred due to both the greater mineral association, which better stabilized the indigenous soil organic matter, and the higher microbial activity in this soil, which accelerated sewage sludge mineralization. Sewage sludge applications increased the C content for the clay and sandy soils by 7.4 and 15.4 g kg(-1), respectively, suggesting a positive effect on these two soils.

One rapidly growing market of Sweden: organic food : A qualitative study portraying some consumers’ decision to purchase organic food

In recent years there has been a significantly rising trend amongst consumers for health and environmental issues, which has resulted in greater attention for and sales of organic food. Organic food production strives to use natural resources, such as land, energy and water in a sustainable way and the products does not contain artificial fertilizers or chemical pesticides. However, organic food products are also often more expensive and less available in comparison to conventional food products. Despite this, interest for and sales of organic food products have increased around the globe, and in Sweden particularly, the increase in sales has grown largely from an international perspective. This thesis is of qualitative character and is focused on studying some consumers from the Swedish market of organic food. The purpose of this thesis is to contribute with a better understanding on the buying decision process regarding organic food purchase. To achieve this, the authors have studied some consumers that purchase organic food and have searched for patterns that could be identified in the decision process. The consumer buying decision process model has been used for portrayal of the chosen consumers’ decision to purchase organic food products. Interviews with six Swedish consumers were conducted, whereas each respondent continuously purchase organic food products. Results show that the purchase of organic food products begins with discovering an unsatisfied need state, which the consumers of this study desired to change with the purchase of organic food products. This study show how six consumers reason when passing through the stages of the buying decision process, in order to satisfy their desired need state. The authors found that the respondents feel satisfied with purchasing organic food products, which lead them in to continuously buying these products. Altogether, the findings contribute with knowledge that can come to be helpful when wanting to understand more about the consumer decision to purchase organic food.

Organic Farms and Local Food Retailers in Maine

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Organic Farms and Agricultural Chemicals in Maine

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