ENSC 1003 Study Guide - Midterm Guide: Anhydrite, Geologic Time Scale, Croup

• School: University of Arkansas
• Department: Environmental Science
• Course: ENSC 1003
• Professor: Lisa S.Wood

Document Summary

Organic n (nitrogen: 78% of atmosphere (n2: molecular nitrogen, rainfall= +10lb/ ac/ yr. Electrical storms, burning fossil fuels, oxidation of sunlight: pant, crop residue= decompose in soil=> form om, om: 4-5% n, 1-3% organic-n= converted for plant uptake. Legume plants= x nitrogen (add several hundreds of pounds/ ac/ yr) 10-40 lb n/ton manure: 1/2 of it= converted, => form available for plant uptake in 1st yr, each subsequent yr= less. Commercial fertilizers: plant available forms nh4+ & no3, microorganisms= transform organic-n into plant available forms. Ammoni cation (mineralization: conversion of organic-n-> ammonium (nh4+, by many soil microorganisms, can be aerobic/ anaerobic, retained by soil due to positive charge which is attracted & held tightly to clay, available to plants. Nitri cation: oxidation of nh4+ -> no2-(nitrite)-> no3-(nitrate, by nitrosomonas sp bacteria (use co2 & c source, not retained by soil (move w. water) Denitri cation: reduction of no3-/no2-> n2 (molecular nitrogen)/ nitrogen oxides, by nitrobacteria sp.