Effects of activated charcoal and quebracho tannins on the turnover of goat manure in irrigated organic agriculture of the subtropics

Agriculture in semi-arid and arid regions is constantly gaining importance for the security of the nutrition of humankind because of the rapid population growth. At the same time, especially these regions are more and more endangered by soil degradation, limited resources and extreme climatic conditions. One way to retain soil fertility under these conditions in the long run is to increase the soil organic matter. Thus, a two-year field experiment was conducted to test the efficiency of activated charcoal and quebracho tannin extract as stabilizers of soil organic matter on a sandy soil low in nutrients in Northern Oman. Both activated charcoal and quebracho tannin extract were either fed to goats and after defecation applied to the soil or directly applied to the soil in combination with dried goat manure. Regardless of the application method, both additives reduced decomposition of soil-applied organic matter and thus stabilized and increased soil organic carbon. The nutrient release from goat manure was altered by the application of activated charcoal and quebracho tannin extract as well, however, nutrient release was not always slowed down. While activated charcoal fed to goats, was more effective in stabilising soil organic matter and in reducing nutrient release than mixing it, for quebracho tannin extract the opposite was the case. Moreover, the efficiency of the additives was influenced by the cultivated crop (sweet corn and radish), leading to unexplained interactions. The reduced nutrient release caused by the stabilization of the organic matter might be the reason for the reduced yields for sweet corn caused by the application of manure amended with activated charcoal and quebracho tannin extract. Radish, on the other hand, was only inhibited by the presence of quebracho tannin extract but not by activated charcoal. This might be caused by a possible allelopathic effect of tannins on crops. To understand the mechanisms behind the changes in manure, in the soil, in the mineralisation and the plant development and to resolve detrimental effects, further research as recommended in this dissertation is necessary. Particularly in developing countries poor in resources and capital, feeding charcoal or tannins to animals and using their faeces as manure may be promising to increase soil fertility, sequester carbon and reduce nutrient losses, when yield reductions can be resolved.

How do consumers perceive organic food from different geographic origins? Evidence from Hong Kong and Shanghai

The objective of this paper is to understand how Chinese consumers perceive certified organic food, especially the differences between locally and nationally produced organic food compared to food produced overseas. In 2012, a consumer survey was conducted at supermarkets in Hong Kong and Shanghai (N=245). Participants were asked for their perception on four different food origins: locally produced organic food, organic food from China, imported organic food, and locally produced conventional food. Consumers in Hong Kong had a positive attitude towards local organic food and imported organic food. However, they were sceptical about organic food from China, in particular regarding chemical residues and the trustworthiness of producers. Consumers in Shanghai, in contrast, had a positive attitude towards all three tested geographical origins of organic food. Overall, the results suggest that it is challenging for marketers to promote and boost the sales of China-produced organic food in China. Better communication is essential to convince consumers that organic food from China is of similar quality as organic food produced elsewhere.

The role of organic farming for food security: local nexus with a global view

A convergence of factors has made food security one of the most important global issues. It has been the core concept of the Milan Expo 2015, whose title, Feeding the Planet, Energy for Life, embodied the challenge to provide the world’s growing population with a sustainable, secure supply of safe, nutritious, and affordable high-quality food using less land with lower inputs. Meeting the food security agenda using current agricultural production techniques cannot be achieved without serious degradation to the environment, including soil degradation, loss of biodiversity and climate change. Organic farming is seen as a solution to the challenge of sustainable food production, as it provides more nutritious food, with less or no pesticide residues and lower use of inputs. A limit of organic farming is its restricted capability of producing food compared to conventional agriculture, thus being an inefficient approach to food production and to food security. The authors maintain, on the basis of a scientific literature review, that organic soils tend to retain the physical, chemical and biological properties over the long term, while maintaining stable levels of productivity and thereby ensuring long-term food production and safety. Furthermore, the productivity gap of organic crops may be worked out by further investment in research and in particular into diversification techniques. Moreover, strong scientific evidence indicates that organic agricultural systems deliver greater ecosystem services and social benefits.

Perception of quality in certified organic pineapples by farmers in Kayunga district, Central Uganda: Implications for food security

In East Africa, Uganda is one of the major producers of organic pineapples for export. These pineapples are mainly produced in central Uganda and have to meet stringent quality standards before they can be allowed on international markets. These quality standards may put considerable strain on farmers and may not be wholly representative of their quality interpretation. The aim of this paper is therefore, to determine the Ugandan organic pineapple farmers’ quality perception, the activities they carry out in order to attain that quality and challenges (production, postharvest & marketing) faced on the same. Qualitative semi-structured interviews were carried out among 28 organic pineapple farmers in Kayunga district, central Uganda. Findings suggest that quality of organic pineapples is mainly perceived in terms of product attributes particularly appearance followed by food security provision. Certification plays a minor role in what farmers describe as organic quality. High production input costs (labour and coffee husks) coupled with a stagnant premium are some of the major challenges faced by farmers in attaining organic quality. The paper argues that currently there are concealed negative food security effects embroiled in these pineapple schemes. It is recommended that the National Organic Agricultural Movement of Uganda (NOGAMU) works with all relevant stakeholders to have the farmer premium price raised and an official organic policy enacted.

Different implications for enterprises of an organic production

This paper reviews the concept of “organic”, its meaning and emphasizes a comparison with conventional goods. It develops the background of organic goods in the past 20 years, quotations different definitions of organic and developing a main definition. Also it states certain criteriab and variables in order to develop a deeper business analysis. And it has the objective to define the advantages, disadvantages, key points and strategies for companies that want to venture an organic production, and if it’s recommendable to pursue. After a cross case and SWOT analysis it is possible to determine that depending of the core strategy and type of company if an enterprise can decide to venture the organic market.

AQA A2 Unit 4 Chemistry : kinetics, equilibria and organic chemistry.

Guía de apoyo para alumnos de educación secundaria de segundo ciclo que sigan la especificación de AQA (Assessment and Qualifications Alliance) en el nivel A2 del área de química. Está dividida en tres secciones: una introducción con consejos y técnicas para la realización del examen; una guía de contenido con los principales conceptos y temas (cinética, equilibrio, ácidos y bases, nomenclatura e isomería en química orgánica, compuestos del grupo carbonilo, química aromática, aminas, aminoácidos, polímeros, análisis y síntesis orgánica y determinación de estructura); y una sección con preguntas de examen y respuestas comentadas por un examinador.

Basis set and electron correlation effects on initial convergence for vibrational nonlinear optical properties of conjugated organic molecules

The level of ab initio theory which is necessary to compute reliable values for the static and dynamic (hyper)polarizabilities of three medium size π-conjugated organic nonlinear optical (NLO) molecules is investigated. With the employment of field-induced coordinates in combination with a finite field procedure, the calculations were made possible. It is stated that to obtain reasonable values for the various individual contributions to the (hyper)polarizability, it is necessary to include electron correlation. Based on the results, the convergence of the usual perturbation treatment for vibrational anharmonicity was examined

Availability and use of organic matter in stream ecosystems: the role of biofilms

La comunitat bentònica dels ecosistemes fluvials processa una gran quantitat de la matèria orgànica que arriba als rius. L'origen de les entrades de material (autòctones o al·lòctones), la seva composició química i la seva quantitat (freqüència de les entrades i concentració assolida en el riu), determinen l'estructura de la comunitat bentònica autotròfica i heterotròfica, les seves relacions tròfiques i les seves interaccions potencials (competència, sinergisme). L'objectiu d'aquesta tesi és posar de manifest la utilització de la matèria orgànica dissolta (MOD) per part dels biofilms bacterians bentònics fluvials i determinar l'eficiència del sistema fluvial en l'ús dels diferents materials que hi circulen. Amb aquesta finalitat s'han portat a terme diversos experiments, tant de camp com de laboratori, per tal de conèixer els efectes de la disponibilitat de la matèria orgànica (quantitat) i la seva qualitat (composició química i biodegradabilitat) i els efectes deguts a l'augment de temperatura de l'aigua del riu.

The role of fungi and bacteria on the organic matter decomposition process in streams: interaction and relevance in biofilms

L'objectiu d'aquest estudi és el d'investigar sobre l'ús de matèria orgànica per part dels fongs i bacteris que colonitzen diferents substrats bentònics en rius Mediterranis i analitzar l'efecte dels factors ambientals i antròpics sobre l'estabilitat estructural i funcional de les comunitats del biofilm. La metodologia emprada en aquest estudi consisteix en: i) anàlisi de la biomassa bacteriana i fúngica, ii) anàlisi de la composició de les comunitats bentòniques (identificació d'hifomicets aquàtics i anàlisi del 16S rDNA bacterià), i iii) anàlisi de l'activitat enzimàtica extracel·lular relacionada amb el reciclatge de matèria orgànica en rius.