“…The humification of plant material of different composition has been investigated primarily in the laboratory (KOLENBRANDER [1955], SPRINGER [1944SPRINGER [ , 1945SPRINGER [ , 1955, SPRINGER and LEHNER [1952a, b], SPRINGER and SEISCHAB [1961]). WAKSMAN and TENNEY [1927a, b] called attention to the fact that young plants with a low methoyxl lignin content decompose easier than older ones with a higher methoxyl content.…”