Specialists can be promoted to corporal, the lowest rank of non-commissioned officer, or NCO. An NCO is an enlisted man with the responsibility to lead other soldiers. Corporals lead teams of a few soldiers within a squad. Each squad of as many as 10 soldiers is led by one or more sergeants or a staff sergeant. In squads with a staff sergeant, the staff sergeant commands any other sergeants in the squad.
Organic soil is soil that contains more than 30 percent of decayed organic material from dead leaves, stems and animals, and this material gives the soil a rich color and fibrous texture. Organic soil also receives and retains moisture, which makes it highly supportive for plant growth.
Clay is the tiniest soil particle. Compared to sand particles, which are generally round, clay particles are thin, flat and covered with tiny plates. Clay particles tend to stick together and make very little movement through soil.umus-rich soils are naturally friable, clay soils are tight and almost impenetrable when dry and sandy soils are loose and coarse and need frequent watering to maintain plant growth. Each of these soils resulted from parent material and climatic effects. An ideal soil contains all three of these different soil types.