Soil Chemical Analysis

B6nassy, C., 1955. R6marques sur deux Aphelinid6s: Aphelinus mytilaspidis Le Baron et Aphytis proclia Walker. Annls l~piphyt. 6: 11-17. Lord, F. T. & MacPhee, A. W., 1953. The influence of spray programs on the fauna of apple orchards in Nova Scotia II. Oyster shell scale. Can. Ent. 79: 196-209. Pickett, A. D., 1946. A progress report on long term spray programs. Rep. Nova Scotia Fruit Grow. Ass. 83 : 27-31. Pickett, A. D., 1967. The influence of spray programs on the fauna of apple orchards in Nova Scotia XIV. Can. Ent. 97: 816-821. Tothill, J. D., 1918. The predacious mite Hemisarcoptes malus Shimer and its relation to the natural control of the oyster shell scale Lepidosaphes ulmi L. Agric. Gaz. Can. 5 : 234-239.

http://link.springer.com/content/pdf/10.1007/BF01976688.pdf

Soil enzymes: Kuprevich, V. F. & Shcherbakova, T. A.: Translated from the Russian edition (1966), published by the Indian National Scientific Documentation Centre, New Delhi 1971. 392 pp., offset printing from type script, paper cover. Obtainable from U.S. Department of Commerce, National Technical Information Service, Springfield, Va. 22151

Citizen and Subject: Contemporary Africa and the legacy of late colonialism

Positive ions that are available in soils absorb on grain surfaces. The total sum of cations that can be absorbed bij a soil/sediment at a certain PH is defined by the cation-exchange capacity (CEC, in meq g-1: mol equivalents per gram). The uptake of cations is an important parameter in agriculture and the larger the CEC, the more cations can be absorbed to the soil. The CEC depends highly on the pH of soil and sediments, where the CEC decreases with decreasing PH (increasing acidity). The exchange of ions on sediments occurs commonly fast on geological time scales, but the kinetics of adsorption in natural environments is still poorly understood. The strength of the bonding between the cations and the sediments varies from weak Van der Waals bondings (physical adsorption) to strong chemical bonds. The CEC is widely used for agricultural assessment because it is a measure of general soil fertility as well as an indicator of structural stability because CED is capabel of enhancing development of shrinkage cracks. The list below shows the CEC for different types of minerals. The data indicate that the CEC can vary over 2 orders of magnitude for various types of , minerals and can vary one order of magnitude within one soil type. Cation exchange capacity for different types of sediment (Eisma, 1992; Locher and de Bakker, 1990):

Cation exchange capacity.

Statistics: Methods and Applications.

Acinetobacter are a major concern because of their rapid development of resistance to a wide range of antimicrobials, and rapid profundity in transformation, surviving desiccation and persistinge in the environment for a very long time. The organisms are associated with bacteraemia, pulmonary infections, meningitis, diarrhea and notorious nosocomial infections with mortality rates of 20 to 60%. Transmission is via person-to-person contact, water and food contamination, and contaminated hospital equipment. The increasing virulence and rapid development of multidrug resistance by these organisms highlights the need to search for alternatives for chemotherapy. A poor understanding of the organisms and dearth of information about their occurrence especially in developing countries informed the need for this review paper.

https://www.jstage.jst.go.jp/article/jsme2/26/2/26_ME10179/_pdf

The Ecology, Biology and Pathogenesis of Acinetobacter spp.: An Overview

Soil enzymes regulate ecosystem functioning and in particular play a key role in nutrient cycling. In this review we briefly summarise potential roles of selected enzymes such as amylase, arylsulphatases, -glucosidase, cellulose, chitinase, dehydrogenase, phosphatase, protease and urease in the ecosystem. We also highlight areas where further research is needed to increase our understanding of other possible role(s) of enzymes and factors that may affect their activities in the ecosystem.

/pdf/selected-soil-enzymes-examples-of-their-potential-roles-in-4szgze8xsy.pdf

Selected soil enzymes: Examples of their potential roles in the ecosystem

Vermicompost contains plant nutrients including N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu and B, the uptake of which has a positive effect on plant nutrition, photosynthesis, the chlorophyll content of the leaves and improves the nutrient content of the different plant components (roots, shoots and the fruits). The high percentage of humic acids in vermicompost contributes to plant health, as it promotes the synthesis of phenolic compounds such as anthocyanins and flavonoids which may improve the plant quality and act as a deterrent to pests and diseases.

	 

	Key words: Phenolic acid, humic acid, earthworms, Eisenia fetida, organic, compost, fertilizer, leachate, photosynthesis, chlorophyll.

http://digitalknowledge.cput.ac.za/bitstream/11189/7527/1/Potential%20of%20vermicompost%20produced%20from%20plant%20waste.pdf

Potential of vermicompost produced from plant waste on the growth and nutrient status in vegetable production

The interest in plants with antimicrobial properties has been revived due to current problems associated with the use of antibiotics with the increased prevalence of multidrug resistant (MDR) bacterial strains. Some emerging species of bacteria such as Escherichia coli 0517: H7 and Acinetobacterspecies that are verocytotoxin producers present further chemotherapeutic challenges because of the increased level of toxin production in medium when challenged with antibiotics. The abundant medicinal plant resources and their antioxidant properties and possibly undiscovered novel modes of action can be a solution to the control of multidrug resistant verocytotoxic bacteria.

	 

	Key words: Antimicrobial, multi-drug resistance, chemotherapy.

http://digitalknowledge.cput.ac.za/bitstream/11189/2637/4/Doughari_JH_Human_IS_Bennade_S_Ndakidemi_PA_AppSci_2009.pdf

Phytochemicals as chemotherapeutic agents and antioxidants: Possible solution to the control of antibiotic resistant verocytotoxin producing bacteria

Flavonoids and nitrogenous metabolites such as alkaloids, terpenoids, peptides and amino acids are major components of plant seeds. Conjugated forms of these compounds are soluble in water, and therefore, are easily released as chemical signals following imbibition. Once in the soil, these metabolites are first in line to serve as eco-sensing signals for suitable rhizobia and arbuscular mycorrhizal (AM) fungal partners required for the establishment of symbiotic mutualisms. They may also serve as defence molecules against pathogens and insect pests, as well as playing a role in the control of parasitic members of the family Scrophulariaceae, especially Striga, a major plant pest of cereal crops in Africa. Seed metabolites such as flavonoids, alkaloids, terpenoids, peptides and amino acids define seedling growth and, ultimately, crop yields. Thus, an improvement in our understanding of seed chemistry would permit manipulation of these molecules for effective control of pathogens, insect pests, Striga and destructive weeds, as well as for enhanced acquisition of N and P via symbioses with soil rhizobia and AM fungi.

Patrick A. Ndakidemi

Papers

The Ecology, Biology and Pathogenesis of Acinetobacter spp.: An Overview

Selected soil enzymes: Examples of their potential roles in the ecosystem

Potential of vermicompost produced from plant waste on the growth and nutrient status in vegetable production

Phytochemicals as chemotherapeutic agents and antioxidants: Possible solution to the control of antibiotic resistant verocytotoxin producing bacteria

Legume seed flavonoids and nitrogenous metabolites as signals and protectants in early seedling development.