scholarly journals Effect of land use, season, and soil depth on soil microbial biomass carbon of Eastern Himalayas

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nima Tshering Lepcha ◽  
N. Bijayalaxmi Devi

Abstract Background Soil microbial biomass, an important nutrient pool for ecosystem nutrient cycling is affected by several factors including climate, edaphic, and land-use change. Himalayan soils are young and unstable and prone to erosion and degradation due to its topography, bioclimatic conditions and anthropogenic activities such as frequent land-use change. Through this study, we tried to assess how soil parameters and microbial biomass carbon (MBC) of Eastern Himalayan soils originated from gneissic rock change with land-use type, soil depth and season. Chloroform fumigation extraction method was employed to determine MBC from different land-use types. Results Soil physical and chemical properties varied significantly with season, land-use and soil depth (p < 0.001). The maximum values of soil properties were observed in the rainy season followed by summer and winter season in all the study sites. Annual mean microbial biomass carbon was highest in the forest (455.03 μg g− 1) followed by cardamom agroforestry (392.86 μg g− 1) and paddy cropland (317.47 μg g− 1). Microbial biomass carbon exhibited strong significant seasonal difference (p < 0.001) in all the land-use types with a peak value in the rainy season (forest-592.78 μg g− 1; agroforestry- 499.84 μg g− 1 and cropland- 365.21 μg g− 1) and lowest in the winter season (forest − 338.46 μg g− 1; agroforestry – 320.28 μg g− 1 and cropland − 265.70 μg g− 1). The value of microbial biomass carbon decreased significantly with soil depth (p < 0.001) but showed an insignificant increase in the second year which corresponds to a change in rainfall pattern. Besides, land-use type, season and soil depth, soil properties also strongly influenced microbial biomass carbon (p < 0.001). Microbial quotient was highest in the agroforestry system (2.16%) and least in the subtropical forest (1.91%). Conclusions Our results indicate that land-use, soil depth and season significantly influenced soil properties and microbial biomass carbon. The physical and chemical properties of soil and MBC exhibit strong seasonality while the type of land-use influenced the microbial activity and biomass of different soil layers in the study sites. Higher soil organic carbon content in cardamom agroforestry and forest in the present study indicates that restoration of the litter layer through retrogressive land-use change accelerates microbial C immobilization which further helps in the maintenance of soil fertility and soil organic carbon sequestration.

2020 ◽  
pp. 34-49
Author(s):  
Alex Amerh Agbeshie ◽  
Simon Abugre ◽  
Rita Adjei ◽  
Thomas Atta-Darkwa ◽  
Joseph Anokye

Land use conversion significantly impact on sensitive soil quality parameters such as microbial biomass and soil microbial quotient. Therefore, soil microbial biomass and physicochemical properties were compared under three different land use systems namely agricultural land, degraded mine land and an adjacent natural forest in the Newmont Gold Ghana Limited concessional areas, Kenyasi, Ghana. In our field experimentation, an area of 300 m2 was demarcated in each land use type for soil sampling. In each of the land use type, we collected soil 5 samples at a depth of 0-15 cm in both the dry and wet seasons respectively. Parameters we measured included soil bulk density, pH, particle size distribution, organic carbon, total nitrogen, available phosphorus, microbial biomass carbon and nitrogen, and moisture content. Our results revealed that land use type significantly impacted on soil microbial biomass and physicochemical properties. Microbial biomass carbon and nitrogen was higher in the forested land compared to the agricultural land and degraded mine land, which was due to relatively higher amounts of litter inputs. Microbial biomass carbon decreased between 20.23 - 88.36% when land use changed from forested land to other land uses. Significant positive correlation was observed between soil microbial biomass and water content, soil organic carbon, phosphorus, clay, nitrogen. Generally, seasonal variation in our study area did not influence soil physical and chemical properties, however, it significantly affected microbial biomass indices. Findings of our study further revealed the importance of forested area in the maintenance of soil quality parameters.


1996 ◽  
Vol 76 (4) ◽  
pp. 459-467 ◽  
Author(s):  
William R. Horwath ◽  
Eldor A. Paul ◽  
David Harris ◽  
Jeannette Norton ◽  
Leslie Jagger ◽  
...  

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


2020 ◽  
Vol 17 (4) ◽  
pp. e1104
Author(s):  
Adriana Montañez ◽  
Natalia Rigamonti ◽  
Silvana Vico ◽  
Carla Silva ◽  
Lucía Nuñez ◽  
...  

Aim of study: This study evaluated the effect of the application of liquid aerobic treated manure (continuous liquid composting, CLC) on physical, chemical and biological soil properties, with the objective of monitoring changes induced by soil management with CLC as a biofertilizer.Area of study: Colonia, Uruguay (lat. 34,338164 S, long. 57,222630 W).Material and methods: Soil’s chemical properties, including nitrogen mineralization potential (NMP) and 15 microbiological properties (microbial biomass carbon, MBC; mesophylic aerobic bacteria; actinobacteria; filamentus fungi; fluorescein diacetate hydrolysis; dehydrogenase; with NMP; acid and alkaline phosphatase; cellulolose degraders; P-solubilizing bacteria; nitrifying; denitrifying and free-living N-fixing microorganisms; glomalin; and soil-pathogenicity index, SPI) were evaluated in two sites with similar cropping history, with one and three years of respective CLC application.Main results: CLC application had significant effects on soil microbial biomass (p<0.05), soil enzyme (p<0.1) and functional groups activity (p<0.05). SPI decreased in both sites with CLC application. No significant variations were detected for the chemical variables, with the exception of NMP, which was significantly high (p<0.05) in soil treated with CLC at both sites.Research highlights: The improved biological soil properties analyzed (MBC, soil enzyme activities and SPI, together with NMP) emerged as reasonable indicators to assess and monitor the effects of CLC application.


2019 ◽  
Vol 11 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Chowlani Manpoong ◽  
S.K. Tripathi

Changes in land use and improper soil management have led to severe land degradation around the globe through the modification in soil physicochemical and biological processes. This study aimed to assess the soil properties of different land use system types. Soil samples (0-15 cm depth) were collected from five land uses; Rubber Plantation (RP), Oil Palm Plantation (OPP), Bamboo Forest (BF), Fallow Land (FL) and Natural Forest (NF) and analyzed for bulk density, soil texture, soil pH, soil moisture, soil carbon, total nitrogen, ammonium, nitrate, soil microbial biomass carbon, soil respiration. Soil pH was lower than 4.9 in all the sites indicating that the surface soil was highly acidic. Soil organic carbon (SOC) and total nitrogen (TN) values ranged from 2.02% to 2.81% and 0.22% to 0.3% respectively. Soil organic carbon (SOC), total nitrogen (TN) and soil microbial biomass (SMBC) were highly affected by soil moisture. NH4+-N and NO3--N ranged from 5.6 mg kg-1 to 10.2 mg kg-1 and 1.15 mg kg-1 to 2.81 mg kg-1 respectively. NF soils showed the maximum soil microbial biomass carbon (SMBC) whereas the minimum was observed in BF with values ranging from 340 mg kg-1 to 345 mg kg-1. Basal respiration was highest in RP (375 mg CO2 m-2 hr-1) and lowest in BF (224 mg CO2 m-2 hr-1). The findings demonstrated significant effect (p<0.05) of land use change on soil nutrient status and organic matter. Findings also indicated that land use change deteriorated native soil physicochemical and biological properties, but that land restoration practices through longer fallow period (>10 years) likely are successful in promoting the recovery of some soil characteristics.


Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 508 ◽  
Author(s):  
Zhiwei Ge ◽  
Shuiyuan Fang ◽  
Han Chen ◽  
Rongwei Zhu ◽  
Sili Peng ◽  
...  

Soil resident water-stable macroaggregates (diameter (Ø) > 0.25 mm) play a critical role in organic carbon conservation and fertility. However, limited studies have investigated the direct effects of stand development on soil aggregation and its associated mechanisms. Here, we examined the dynamics of soil organic carbon, water-stable macroaggregates, litterfall production, fine-root (Ø < 1 mm) biomass, and soil microbial biomass carbon with stand development in poplar plantations (Populus deltoides L. ‘35’) in Eastern Coastal China, using an age sequence (i.e., five, nine, and 16 years since plantation establishment). We found that the quantity of water-stable macroaggregates and organic carbon content in topsoil (0–10 cm depth) increased significantly with stand age. With increasing stand age, annual aboveground litterfall production did not differ, while fine-root biomass sampled in June, August, and October increased. Further, microbial biomass carbon in the soil increased in June but decreased when sampled in October. Ridge regression analysis revealed that the weighted percentage of small (0.25 mm ≤ Ø < 2 mm) increased with soil microbial biomass carbon, while that of large aggregates (Ø ≥ 2 mm) increased with fine-root biomass as well as microbial biomass carbon. Our results reveal that soil microbial biomass carbon plays a critical role in the formation of both small and large aggregates, while fine roots enhance the formation of large aggregates.


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