HUMUS

Read the given statements and select the correct option. Statement 1 : Decompsotion is the physical and chemical breakdown of complex organic matter into simple inorganic substances. Statements 2: Humification is the process of formation of humus from detritus or organic remains.

Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil and one a control without humus. The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in humus-enriched soil. The best explanation for this difference is that