Grass litter decomposition rate and water-holding capacity in dry-hot valley of Jinshajiang River

The decomposition rate and the water-holding capacity of 6 kinds of grass litters were studied in the Jinshajing river dry-hot valley. The results showed that the dry weight remains reduced with time but didn’t have the direct correlation with time. The decomposition litters were affected by climate, character of litter, animalcule and soil animal. The climate factors of temperature and humidity were important especially. The water-holding capacity was in sequence of N. wightii (336%), P. notatum Flugge (248%), H. contortus (L.) Beauv (209%), B. pertusa (L.) A. Camus(206%), I. endecaphylla Jacq (174%), D. annulatum (Forsk.) Stapf (168%). After 24 months decomposition the remaining dry weight of the litter was in sequence as the following: 15.12% for N. wightii, 26.38% for I. endecaphylla Jacq, 27.23% for B. pertusa (L.) A. Camus, 30.78% for P. notatum Flugge, 39.72% for H. contortus (L.) Beauv and 39.76% for D. annulatum (Forsk.) Stapf. The decomposition rate and water-holding capacity of N. wightii are at the highest level. It is important for the development, improvement and conservation of the grassland soil. Foundation item: Supported by the National Science and Technology Supporting Program in the Eleventh Five-Year Plan of China (2006BAC01A11)