The following is a quote from an article in the August 18, 1998, issue of The New York Times about the breakdown of cellulose and starch: “A drop of 18 degrees Fahrenheit [from 77°F to 59°F] lowers the reaction rate six times; a 36-degree drop [from 77°F to 41°F ] produces a fortyfold decrease in the rate.” (a) Calculate activation energies for the breakdown process based on the two estimates of the effect of temperature on rate. Are the values consistent? (b) Assuming the value of Ea calculated from the 36-degree drop and that the rate of breakdown is first order with a half-life at 25°C of 2.7 years, calculate the half-life for breakdown at a temperature of -15°C.
1 Plsc 101 Exam 3 Fertilizers 67 pH optimum uptake in soil Fertilizer Formulations liquid soluble forms solution in water; applied directly to plants and available immediately two slow release types: granular granules; noncoated; evenly spread around plants water aids breakdown of some medium vs. coarse grade & longevity coated coated with a plastic or sulfur moisture or temp activated ex: Osmocote® uses a porous plastic resin 201020: 20% nitrogen; 10% phosphate; 20% potassium [not always the whole % of phosphate & potassium because oxygen is also with it: P O ] 2 5 Nutrient Mobility chelation compound formed when a metallic ion (micronutrient) binds to a molecule (organic matter) increases solubility of Fe, Zn, Cu, & Mn always a metal that requires chelation Fertilizer Filler filler: carrier of fertilizer ensures even distribution of nutrients helps prevent fertilizer “burn” of plants [take up 2 many nutrients at once] types of filler: biosolids (sewage sludge)
