scholarly journals Comparative Study on Soil Microbial Biomass in Tarai and Hill Sal (Shorearobusta Gaertn.) Forests of Tropical Region in Eastern Nepal

2020 ◽  
Vol 19 (1) ◽  
pp. 16-25
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal
Keyword(s):  
Microbial Biomass ◽  
Comparative Study ◽  
Rainy Season ◽  
Turnover Rate ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
Soil Samples ◽  
Tropical Region ◽  
Soil Microbial ◽  
Sal Forest

A comparative study was conducted to investigate the effect of altitudinal variation and seasonality on soil microbial biomass carbon (MB-C), nitrogen (MB-N), and phosphorus (MB-P) between Tarai Sal forest (TSF) and Hill Sal forest (HSF) of the tropical region in eastern Nepal. Soil microbial biomass was estimated by chloroform fumigation - extraction method in summer, rainy and winter seasons in the upper (0-15 cm) soil depth in both forests. Pre-conditioned soil samples were saturated with purified liquid chloroform, represented fumigated sample. Another set of soil samples without using chloroform, represented unfumigated samples and soil biomass was estimated from these samples. MB-C, MB-N, and MB-P were higher by 66%, 31%, and 9%, respectively, in HSF than TSF. Distinct seasonality was observed in soil microbial biomass. It was maximum in summer and minimum in rainy season in both the forest stands. The value decreased from summer to rainy season by 46 to 67% in HSF and by 32 to 80% in TSF. Higher soil microbial biomass in the summer season may be due to its accumulation in soil when the plant growth and nutrient demand are minimal. Analysis of variance suggested that MB-C, MB-N, and MB-P were significantly different for both sites and seasons (P < 0.001). Soil organic carbon, TN, and TP were positively correlated with MB-C, MB-N, and MB-P in both the forests. In conclusion, the higher value of soil microbial biomass in HSF may be due to the higher concentration of soil organic matter and decreasing turnover rate of microbial biomass due to higher altitude. On the other hand, the lower value of microbial biomass at TSF may indicate its fast turnover rate due to lowland tropics to enhance the nutrient cycling process.

scholarly journals Defining a realistic control for the chloroform fumigation-incubation method using microscopic counting and 14C-substrates

1996 ◽  
Vol 76 (4) ◽  
pp. 459-467 ◽  
Author(s):  
William R. Horwath ◽  
Eldor A. Paul ◽  
David Harris ◽  
Jeannette Norton ◽  
Leslie Jagger ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Soil Depth ◽  
Temporal Trends ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Microbial C ◽  
Parameter Values ◽  
Chloroform Fumigation

Chloroform fumigation-incubation (CFI) has made possible the extensive characterization of soil microbial biomass carbon (C) (MBC). Defining the non-microbial C mineralized in soils following fumigation remains the major limitation of CFI. The mineralization of non-microbial C during CFI was examined by adding 14C-maize to soil before incubation. The decomposition of the 14C-maize during a 10-d incubation after fumigation was 22.5% that in non-fumigated control soils. Re-inoculation of the fumigated soil raised 14C-maize decomposition to 77% that of the unfumigated control. A method was developed which varies the proportion of mineralized C from the unfumigated soil (UFC) that is subtracted in calculating CFI biomasss C. The proportion subtracted (P) varies according to a linear function of the ratio of C mineralized in the fumigated (FC) and unfumigated samples (FC/UFC) with two parameters K1 and K2 (P = K1FC/UFC) + K2). These parameters were estimated by regression of CFI biomass C, calculated according to the equation MBC = (FC − PUFC)/0.41, against that derived by direct microscopy in a series of California soils. Parameter values which gave the best estimate of microscopic biomass from the fumigation data were K1 = 0.29 and K2 = 0.23 (R2 = 0.87). Substituting these parameter values, the equation can be simplified to MBC = 1.73FC − 0.56UFC. The equation was applied to other CFI data to determine its effect on the measurement of MBC. The use of this approach corrected data that were previously difficult to interpret and helped to reveal temporal trends and changes in MBC associated with soil depth. Key words: Chloroform fumigation-incubation, soil microbial biomass, microscopically estimated biomass, carbon, control, 14C

scholarly journals Impact of cadmium and lead on soil microbial biomass nitrogen of the botanical garden of ahmadu bello university, Zaria, Nigeria

2018 ◽  
Vol 3 (3) ◽  
pp. 94-97
Author(s):  
Oijagbe IJ ◽  
Abubakar BY ◽  
Edogbanya PRO
Keyword(s):  
Microbial Biomass ◽  
Room Temperature ◽  
Soil Microbial Biomass ◽  
Botanical Garden ◽  
Soil Samples ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial ◽  
Soil Microbial Biomass Nitrogen ◽  
Cadmium And Lead ◽  
Chloride Salts

This study is aimed at evaluating the effect of heavy metals on soil microbial processes. The effects of Lead (Pb) and Cadmium (Cd) at different concentrations were investigated over a period of eight weeks. Chloride salts of Pb and Cd were added singly and in combination to soil samples at room temperature (27°C) in different polythene bags. Samples were taken from the bags at two weeks interval and measurements were taken of the rate of microbial biomass nitrogen (MBN). The results showed that there was a significant decrease in the microbial biomass for all treated soils from the second week to the sixth week. But there was an observed increase in microbial biomass Nitrogen on the eight week. On the 6thweek, 40mgkg-1Cd gave the most significant decrease (16µg/g) and 1000mgkg-1 Pb gave the least significant decrease (70µg/g) of MBN.

scholarly journals Grass-Legume Mixtures for Improved Soil Health in Cultivated Agroecosystem

2018 ◽  
Vol 10 (8) ◽  
pp. 2718 ◽  
Author(s):  
Dhruba Dhakal ◽  
M. Islam
Keyword(s):  
Microbial Biomass ◽  
Production System ◽  
Soil Microbial Biomass ◽  
Soil Health ◽  
Soil Samples ◽  
N Fertilizer ◽  
Entire Study ◽  
Soil C ◽  
Soil Microbial ◽  
C And N

Planting grass-legume mixtures may be a good option to improve soil health in addition to increased forage productivity, improved forage nutritive value, and net farm profit in a hay production system. A field experiment was conducted from 2011 to 2014 at Lingle, Wyoming to evaluate soil microbial biomass under different seeding proportions of two forage grasses (meadow bromegrass, Bromus biebersteinii Roem. & Schult.; and orchardgrass, Dactylis glomerata L.) and one legume (alfalfa, Medicago sativa L.). Nine treatments included monoculture grass, monoculture legume, one grass and one legume mixture, two grasses and one legume mixture, and a control (not seeded with grass or legume). Monoculture grass received either no nitrogen (N) or N fertilizer (150 kg N ha−1 year−1 as urea) whereas monoculture legume, grass-legume mixtures, and control plots received no N fertilizer. The study was laid out as a randomized complete block design with three replications. The plots were harvested 3–4 times each year after the establishment year. Soil samples were collected and analyzed for microbial biomass using phospholipid fatty acid (PLFA) analysis at the end of May in 2013 and 2014. Soil samples were also analyzed for mineralizable carbon (C) and N in 2013 and 2014. The total above-ground plant biomass was higher in 50–50% mixture of grass and alfalfa than monoculture alfalfa and monoculture grass (with and without N fertilizer) during the entire study period. The application of N fertilizer to the grass hay production system had little effect on improving mineralizable soil C, N, and soil microbial biomass. However, grass-legume mixture without N fertilizer had great effect on improvement of mineralizable soil C and N, and total, bacterial, and actinomycetes microbial biomass in soil. The 50–50% mixture of grass and alfalfa performed consistently well and can be considered to use in Wyoming conditions for improving soil health and forage productivity.

scholarly journals Stoichiometric characteristics of microbial biomass in oil-contaminated soil in the loess hilly region

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Lei Shi ◽  
Zhongzheng Liu
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Contaminated Soil ◽  
Soil Microbial Biomass ◽  
Oil Pollution ◽  
Soil Samples ◽  
Oil Well ◽  
Soil Microbial ◽  
Petroleum Contaminated Soil ◽  
Petroleum Pollutants

Abstract Purpose The present study envisaged the stoichiometry of microbial biomass in petroleum-contaminated soil, in order to study the influence of the petroleum-contaminated soil on the ecosystem stability. Methods A typical oil well area in the Northern Shaanxi was considered the research object and the oil pollution status was assessed by studying the physical, chemical, and microbiological characteristics of the soil in the area. Results From the measurement and analysis of the petroleum pollutants in the soil samples, it was observed that the concentration of the petroleum pollutants around all the oil well areas was higher than the critical value of 500 mg/kg. Furthermore, the C to N ratio of 8 soil samples around the oil wells (0.8:1~13.3:1) was lower than that of the control soil samples in most cases and could not reach the nutrient proportion level required by soil microorganisms. It was observed that the oil organic carbon content at 0~10 m from the wellhead was obviously higher than that in other areas, and decreased with an increase in the distance from the well. Based on the determination of soil organic carbon, total nitrogen, total phosphorus, and the soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and phosphorus content analysis, it was observed that only the soil organic carbon was significantly positively correlated to the oil pollutants in soil. Conclusions Imbalance in the C to N, SMBC, and SMBN ratio can lead to an acute shortage of the required nutrients than microorganisms, limit the soil microbial reproduction and growth, and thereby slow down the rate of indigenous microbial degradation of petroleum hydrocarbons, so as to reduce the impact of oil pollution on the stability of the entire ecosystem. Therefore, during the remediation of petroleum-contaminated soil in this study area, adequate nutrients need to be reasonably added to the soil.

scholarly journals Soil fungal and bacterial biomass determined by epifluorescence microscopy and mycorrhizal spore density in different sugarcane managements

2014 ◽  
Vol 44 (4) ◽  
pp. 588-594 ◽  
Author(s):  
Adriana Pereira Aleixo ◽  
Glaciela Kaschuk ◽  
Odair Alberton
Keyword(s):  
Microbial Biomass ◽  
Nutrient Cycling ◽  
Soil Microbial Biomass ◽  
Bacterial Biomass ◽  
Soil Samples ◽  
Epifluorescence Microscopy ◽  
Spore Density ◽  
Native Forest ◽  
Soil Microbial ◽  
Dry Soil

Crop productivity and sustainability have often been related to soil organic matter and soil microbial biomass, especially because of their role in soil nutrient cycling. This study aimed at measuring fungal and bacterial biomass by epifluorescence microscopy and arbuscular mycorrhizal fungal (AMF) spore density in sugarcane (Saccharum officinarum L.) fields under different managements. We collected soil samples of sugarcane fields managed with or without burning, with or without mechanized harvest, with or without application of vinasse and from nearby riparian native forest. The soil samples were collected at 10cm depth and storage at 4°C until analysis. Fungal biomass varied from 25 to 37µg C g-1 dry soil and bacterial from 178 to 263µg C g-1 dry soil. The average fungal/bacterial ratio of fields was 0.14. The AMF spore density varied from 9 to 13 spores g-1 dry soil. The different sugarcane managements did not affect AMF spore density. In general, there were no significant changes of microbial biomass with crop management and riparian forest. However, the sum of fungal and bacterial biomass measured by epifluorescence microscopy (i.e. 208-301µg C g-1 dry soil) was very close to values of total soil microbial biomass observed in other studies with traditional techniques (e.g. fumigation-extraction). Therefore, determination of fungal/bacterial ratios by epifluorescence microscopy, associated with other parameters, appears to be a promising methodology to understand microbial functionality and nutrient cycling under different soil and crop managements.

scholarly journals Soil microbial biomass in relation to fine root in Kiteni hill Sal forest of Ilam, eastern Nepal

2013 ◽  
Vol 2 ◽  
pp. 80-87
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Total Nitrogen ◽  
Root Biomass ◽  
Soil Microbial Biomass ◽  
Fine Root ◽  
Sandy Loam ◽  
Fine Root Biomass ◽  
Soil Microbial ◽  
Sal Forest

Soil microbial biomass in relation to fine root was studied in Kiteni hill Sal (Shorea robusta) forest of Ilam during summer season. The forest had sandy loam type of soil texture. Organic carbon was higher in 0-15 cm depth (2.09%) than in 15-30 cm depth (1.53%). Total nitrogen of 0- 15 cm depth was 0.173% and in 15-30 cm depth was 0.124%. Soil microbial biomass of carbon of Kiteni hill sal forest was (445.14 ?g g-1) and microbial biomass of nitrogen was (49.07 ?g g-1). Fine root biomass of this forest was 2.34 t ha-1 (<2 mm diameter) and 0.93 t ha-1 (2-5 mm diameter) in 0-15 cm depth and 0.73 t ha-1 (<2 mm diameter) and 0.46 t ha-1 (2-5 mm diameter) in 15-30 cm depth. Organic carbon, total nitrogen, soil microbial biomass carbon and nitrogen of upper layer soil were negatively correlated with fine root biomass of forest. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7493 Nepalese Journal of Biosciences 2 : 80-87 (2012)

scholarly journals Soil microbial biomass in cropland and forest ecosystem in eastern Nepal

2013 ◽  
Vol 3 (1) ◽  
pp. 69-74
Author(s):  
T.N. Mandal
Keyword(s):  
Microbial Biomass ◽  
Forest Ecosystem ◽  
Paddy Field ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Cropping Systems ◽  
Natural Ecosystem ◽  
Soil Microbial ◽  
Sal Forest ◽  
Nutrients Cycling

Soil microbial biomass carbon (MB-C) and nitrogen (MB-N) were estimated in some man-made cropland ecosystems and Sal forest natural ecosystem in eastern Nepal. In these cropping systems MB-C ranged between 244 µg g-1 and 425 µg g-1 soil, minimum in tea cultivation and maximum in uncultivated paddy field. MB –N ranged from 24.7 µg g-1 to 43.2 µg g-1 soil, which was minimum in paddy field at mature crop stage and maximum in uncultivated paddy field. Towards natural ecosystem five landslide damaged sites selected in Sal forest ecosystem were 1 yr., 4yr., 15yr., 40yr., and 58-year old. Under these sites MB-C was minimum (132μg g-1) in 1-yr old site and maximum (638 µg g-1) in 58- yr old site. Similarly, MB-N was also minimum (14 µg g-1) in 1-yr and maximum (55 µg g-1) in 58- yr old site. In comparison to undisturbed mature Sal forest 58 year old site showed 82 % recovery in soil microbial biomass which indicates the re-establishment of soil nutrients and restitution of nutrients cycling.

scholarly journals Changes in Soil Microbial Biomass, Community Composition, and Enzyme Activities After Half-Century Forest Restoration in Degraded Tropical Lands

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1124 ◽  
Author(s):  
Huiling Zhang ◽  
Xin Xiong ◽  
Jianping Wu ◽  
Jianqi Zhao ◽  
Mengdi Zhao ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Soil Depth ◽  
Microbial Properties ◽  
Soil Microbial ◽  
Eucalyptus Forest ◽  
Different Seasons ◽  
Microbial Groups

Soil carbon (C) sequestration and stabilization are determined by not only the C input to the soil but also the decomposition rate of soil organic matter (SOM), which is mainly mediated by soil microbes. Afforestation, an effective practice to restore forests from degraded or bare lands, may alter soil microbial properties, and thus soil C and nitrogen (N) dynamics. The aim of this study was to investigate the impacts of different afforestation strategies on soil microbial compositions and activities after afforestation for half a century. Soil samples were collected from two afforested sites (i.e., a restored secondary forest (RSF) and a managed Eucalyptus forest (MEP)) and two reference sites (i.e., a nearby undisturbed forest (UF), representing the climax vegetation and a bare land (BL), representing the original state before restoration) in south China. We quantified the soil microbial biomass, microbial community compositions, and activities of nine extracellular enzymes at different soil depths and in different seasons. Results showed that the soil microbial biomass, all the main soil microbial groups, and the activities of all extracellular enzymes were significantly increased after afforestation compared to the BL sites, while the ratios of fungi/bacteria (F/B), specific enzyme activities, and the ecoenzymatic stoichiometry were significantly decreased regardless of the season and soil depth. Between the two afforested sites, these microbial properties were generally higher in the RSF than MEP. However, the microbial properties in the RSF were still lower than those in the UF, although the differences varied with different seasons, soil depths, and microbial groups or enzymes. Our findings demonstrated that afforestation might significantly improve microbial properties. Afforestation is more effective in mixed-species plantation than in the monoculture Eucalyptus plantation but needs a much longer time to approach an equivalent level to the primary forests.

Effects of Nitrogen Deposition on Soil Microbial Biomass, Microbial Functional Diversity and Enzyme Activities in Fir Plantations of Subtropical China

2012 ◽  
Vol 610-613 ◽  
pp. 323-330 ◽  
Author(s):  
Ying Hong Yuan
Keyword(s):  
Microbial Biomass ◽  
Functional Diversity ◽  
Polyphenol Oxidase ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
N Deposition ◽  
Soil Parameters ◽  
Microbial Functional Diversity ◽  
Soil Microbial

The effects of simulated nitrogen (N) deposition on soil microbial biomass, microbial functional diversity and enzyme activities involved in C cycling (sucrase, β-glucosidase, cellulose, amylase, polyphenol oxidase and peroxidase) were studied in southeast Chinese fir plantation (Cunninghamialanceolata (Lamb.)). All soil parameters measured decreased with increasing soil depth. The results indicated that low N (N1) deposition could accelerate soil microbial biomass and functional diversity, but moderate or high N deposition (N2, N3) restrain them. Nitrogen additions promoted soil sucrase, β-glucosidase and cellulase activities, while inhibited soil amylase, polyphenol oxidase and peroxidase activities to some extent, suggesting that decomposition of labile and recalcitrant organic matter were promoted and restricted by extra N deposition, respectively. Changes in microbial community biomass and function under extra N deposition indicated soil ecosystems experienced functional shifts under the current or future condition of human-accelerated N supply.

Variation in soil microbial biomass in the dry tropics: impact of land-use change

Soil Research ◽  
2014 ◽  
Vol 52 (3) ◽  
pp. 299 ◽  
Author(s):  
Mahesh Kumar Singh ◽  
Nandita Ghoshal
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
Natural Forest ◽  
Microbial Biomass C ◽  
Soil Microbial Biomass C ◽  
Soil Microbial ◽  
Land Use Types ◽  
C And N

The impact of land-use change on soil microbial biomass carbon (C) and nitrogen (N) was studied through two annual cycles involving natural forest, degraded forest, agroecosystem and Jatropha curcas plantation. Soil microbial biomass C and N, soil moisture content and soil temperature were analysed at upper (0–10 cm), middle (10–20 cm) and lower (20–30 cm) soil depths during the rainy, winter and summer seasons. The levels of microbial biomass C and N were highest in the natural forest, followed in decreasing order by Jatropha curcas plantation, degraded forest and the agroecosystem. The highest level of soil microbial biomass C and N was observed during summer, decreasing through winter to the minimum during the rainy season. Soil microbial biomass C and N decreased with increasing soil depth for all land-use types, and for all seasons. Seasonal variation in soil microbial biomass was better correlated with the soil moisture content than with soil temperature. The microbial biomass C/N ratio increased with the soil depth for all land-use types, indicating changes in the microbial community with soil depth. It is concluded that the change in land-use pattern, from natural forest to other ecosystems, results in a considerable decrease in soil microbial biomass C and N. Jatropha plantation may be an alternative for the restoration of degraded lands in the dry tropics.

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