Soil Microbial Biomass Carbon and Nitrogen in Himalayan Rangeland of Eastern Nepal: a Comparison between Grazed and Ungrazed Rangeland

Document Type: Research and Full Length Article

Authors

1 Central Department of Environmental Science, Tribhuvan University, Kathmandu

2 Biology, Central Campus of Technology, Dharan, Tribhuvan University

3 School of Life Science, Lanzhou University

Abstract

Soil microbial biomass plays an important role in nutrient transformation in terrestrial ecosystems. Microbial biomass is also an early indicator of changes in total soil organic carbon (C). Thus, the main objective of this study is to identify and quantify the present status of soil microbial biomass carbon and nitrogen at various management practices in Himalayan rangeland. To meet the aforementioned objectives, the field study was conducted in 2011 -2013 in Tinjure Milke Jaljale (TMJ) eastern Himalaya Nepal. Soil samples were collected from depths of 0 – 15 cm at 3 soil cores in each quadrat. Quadrat size was 30 cm x 30 cm and core size was 4.00 cm in diameter and 15 cm deep. Composite soil sample was made with mixing of all sample of a quadrat. 5 quadrats were taken from each subplot. Soil core was separated into three sections viz. 0-5, 5-10 and 10-15 cm slice with 5 cm length of each slice. Soil sample analysis was carried out by the process of chloroform fumigation method. The study showed that soil microbial biomass carbon range from 219.84 mg/kg to 987.5 mg/kg. The soil microbial biomass carbon was in increasing trend with decreasing of grazing intensity of the rangeland and differences were significant. Similarly, the value of soil microbial biomass nitrogen was significantly highest in occasional grazing plot, 207.72 mg/kg. Soil microbial biomass carbon and nitrogen values were in decreasing trend with increasing of soil depth of the rangeland.

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