( Humus ( ( is ( ( ( the ( organic residues ) ) ( of ( zillions ( of ( living beings ) ) ) ) ) ( ( ( whose life ) chemicals ) ( take ( ( varying periods ) ( of ( time ( to decay ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Humus)) (VP (VBZ is) (NP (NP (DT the) (JJ organic) (NNS residues)) (PP (IN of) (NP (NP (NNS zillions)) (PP (IN of) (NP (NN living) (NNS beings))))) (SBAR (WHNP (WP$ whose) (NN life) (NNS chemicals)) (S (VP (VBP take) (NP (NP (VBG varying) (NNS periods)) (PP (IN of) (NP (NP (NN time)) (PP (TO to) (NP (NN decay))))))))))) (. .)))
Humus is the organic residues of zillions of living beings whose life chemicals take varying periods of time to decay.
(ROOT (S (NP (NP (DT The) (JJ decayed) (NNS remains)) (PP (IN of) (NP (VBG living) (NNS organisms)))) (VP (VBZ is) (VP (VBN called) (NP (NNS humus)))) (. .)))