Accumulation of soil organic matter after yearly application % of organic materials for 4 years 20 〔r1+2+r3=r4) tter 的(2/、m1(1 100 /d, Decomposition Decomposition rate for 4 years rate after 1 year ld. +d+d+d Decomposition rate in one year after yearly applications over 4 cars 60 d,: after 2 years 100 Remaining id. after 3 rate after years year 20 fdo after 4 years r. after 2 years (5 3 years after 4 years 3 200 Time years]