Tables a in chl 1. (10) compare and contrast ca, p and fe with respect to (a) how they are classified in chapter with respect to relative plant uptake, (b) what their ionic form(s) would be in soil solution, and (c) for ca and p, approximately how much (kg/ha/15 cm) of each ion would be found in a typical humid region soil in total, exchangeable, and solution forms (each) at a given time. a.) 2. (10) (a) define the "pedosphere" concept and give a brief description of its four major component domains and associated fields of science. (b) of these various domains, which one is the primary reservoir of essential plant nutrients and which one actually provides those nutrients to the plant root for uptake? (c) which domain has been subject to the most environmental regulation and public concern over the past 30 to 40 years?