scholarly journals EFFECT OF WATER AVAILABILITY ON SOIL MICROBIAL BIOMASS IN SECONDARY FOREST IN EASTERN AMAZONIA

2015 ◽  
Vol 39 (2) ◽  
pp. 377-384 ◽  
Author(s):  
Lívia Gabrig Turbay Rangel-Vasconcelos ◽  
Daniel Jacob Zarin ◽  
Francisco de Assis Oliveira ◽  
Steel Silva Vasconcelos ◽  
Cláudio José Reis de Carvalho ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Microbial Biomass ◽  
Soil Water ◽  
Water Availability ◽  
Soil Microbial Biomass ◽  
Secondary Forest ◽  
Microbial Biomass Carbon ◽  
Basal Respiration ◽  
Soil Water Availability ◽  
Soil Microbial

Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to determine basal respiration (CO2-SMB). The metabolic quotient (qCO2) and ratio of microbial carbon:organic carbon (CMIC:CORG) were calculated based on those results. Soil moisture was generally significantly lower during the dry season and in the control plots. Irrigation raised soil moisture to levels close to those observed during the rainy season, but had no significant effect on SMB. The variables did not vary on a seasonal basis, except for the microbial C/N ratio that suggested the occurrence of seasonal shifts in the structure of the microbial community.

scholarly journals Soil properties under different land use systems of Mizoram, North East India

2019 ◽  
Vol 11 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Chowlani Manpoong ◽  
S.K. Tripathi
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Soil Microbial

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.

scholarly journals Microbial responses to doses of cover plant straw in cerrado piauiense oxisol

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Sarah Priscilla do Nascimento Amorim ◽  
Cacio Luiz Boechat ◽  
Lizandra de Sousa Luz Duarte ◽  
Daniela Fernandes de Oliveira ◽  
João Carlos Medeiros ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Microbial Population ◽  
Microbial Biomass Carbon ◽  
Basal Respiration ◽  
Microbial Biomass C ◽  
Biomass Carbon ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
Soil Basal Respiration

Carbon and nitrogen from the soil microbial biomass play a significant role in the rotation of C and N, and promote nutrient cycling. Thus, the objective of this study was to evaluate changes in the soil microbial biomass with growing doses of cover plant straw species. The cover plants cultivated in the cerrado biome region were incorporated an Oxisol Ustox. The straw of each cover plant was incorporated at doses of 0; 10; 20 and 30 Mg ha-1. The soil basal respiration was determined by incubating, after 21 days. The microbial biomass carbon and nitrogen were determined by the method the microwave irradiation. The microbial biomass carbon and nitrogen contents in extracts were determined by the wet combustion method and Kjeldahl-N. The metabolic quotient was calculated as the ratio between soil basal respiration rate and microbial biomass C, and the microbial quotient as the ratio between soil microbial biomass C and total carbon of soil. The soil microbial population measured by the attributes of quality responds to the addition of the of grass and legume straws incorporated to the soil; The treatments that cause the greatest stress to the microbial population, at 21 days, mediated by the metabolic quotient, are guandu-anão at a dose of 10 Mg ha-1; Guandu-anão and Guandu fava-larga at 20 Mg ha-1 and Brachiária at a dose of 30 Mg ha-1; The best result regarding microbial attributes of soil quality evaluated was observed with the incorporation of all doses of the straw of Crotalaria-ocroleuca.  

scholarly journals Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 508 ◽  
Author(s):  
Zhiwei Ge ◽  
Shuiyuan Fang ◽  
Han Chen ◽  
Rongwei Zhu ◽  
Sili Peng ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Microbial Biomass ◽  
Fine Root ◽  
Microbial Biomass Carbon ◽  
Critical Role ◽  
Stand Age ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Soil Microbial Biomass Carbon

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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