Rate of Decomposition of Plant Litter and Factors Affecting it

The plant materials largely consist of lignified cell wall materials viz cellulose, hemi-cellulose and lignin being the three major structural components. The present study revealed the lignocellulosic factors affecting the decomposition of different plant residues. The litters of different plants do not decompose at the same rate under similar environmental conditions. Coniferous litter decomposes very slowly upto 31 years as compared to deciduous litters that decompose rapidly, considerable difference exists between different types. The difference may be due to difference in anatomy of litters, nutrient status and the possible production of substances toxic to microorganisms. Even the two different parts of the same plant, may have different rates of decomposition. The nutrient contents of plant litters have significant correlation with the rate of decomposition. Addition of nitrogen, phosphorus and iron accelerated the rate of decomposition in optimum concentration. The rate of decomposition is also affected with placement of litter as incorporated litter in to soil decompose more rapidly as compared to those left on the soil surface. The ratio of pentosans to lignin also controls the rate of decomposition of litters; if the ratio of pentosans to lignin was more than 1, the rate of decomposition will be faster; if 1.0–0.5 then the rate of decomposition will be slow and if 0.5–0.3 then, it will be decomposed very slowly. The optimum temperature and the moisture have been found to be a major controlling factor in rate of litter decomposition.