APPENDIX B 117 



in all sorts of conditions, from cattails in quiet pools to algae on rocks 

 in the swiftest water. Each has its problems, in a sense, of living suc- 

 cessfully there, but cannot manage the environment as man can. 



(3) The four plants groups or phyla should be observed, if possi- 

 ble, in one place. An exposed rock or cliff may provide the whole 

 picture of algae, lichen, moss, fern, shrub or tree, and grass. The soil 

 conditions will vary from raw rock to several inches of topsoil. The 

 way the various stages of plant succession alter the living conditions 

 may be easily seen by close examination and a little digging with the 

 fingers or a stick. The accumulation of humus, disintegrated rock, 

 and airborne dust not only have built soil but also a capacity for 

 holding water. 



CHAPTER VI 



(1) If topsoil is "the dispensing agent for the mineral salts 

 essential to life," and if "topsoil was fabricated by life and death," 

 we would suspect a close relation between the depth of topsoil and the 

 quality and amount of vegetation, dead and alive. While a spade, 

 mattock, or soil auger may be frightening implements to the unitiated, 

 there will be someone about with the lion's heart undoubtedly neces- 

 sary to tote and wield one of them. Explore the source of the dollar's 

 worth of minerals you are made of. Dig down in the soil to the rocky 

 parent material, the C horizon of the soil profile. Expose the topsoil 

 layer or A horizon, and the subsoil B horizon. The labor will be 

 negligible along a creek bank or road cut. You may find a steam- 

 shovelled excavation ready for your inspection. 



But, you have your weapon, so dig on the hilltop; dig on slopes 

 of various degrees ; dig in the bottomland. Dig in the woods ; dig in 

 the grasslands. Dig where the vegetation is succulent and heavy, and 

 where it is tough and scanty. Dig in virgin soil and in old, mistreated 

 cropland. 



When you dig, note the depth and color of the topsoil. Note the 

 amount of raw humus, the size of soil granules. Compare the amount 

 of roots in the topsoil with the amount of the subsoil. Smell the top- 

 soil; smell the subsoil; where is life and death? Then, always judge 

 the correlation between the condition of the topsoil and the vegetation 

 growing on it. 



What is the minimum depth of topsoil which supports a good 

 vegetative cover ? How many inches of topsoil would you spread on a 

 lawn, built of earth materials from a basement excavation, to insure 

 a good turf? Can commercial fertilizer (N P K nitrogen, phosphor- 

 ous, potash) take the place of humus laden topsoil? Why? 



If your county has a Soil Conservation District, the conserva- 

 tionist from the U.S. Department of Agriculture assigned thereto can 

 be of great help in learning about local soils. Look him up. 



(2) What has water done in shaping your environment ? Do you 

 live on the flat limestone floor of an ancient shallow sea, on the sandy 



