IMPACT OF ELEMENTAL SULFUR FERTILIZATION ON AGRICULTURAL SOILS. I. EFFECTS ON MICROBIAL BIOMASS AND ENZYME ACTIVITIES

1988 ◽  
Vol 68 (3) ◽  
pp. 463-473 ◽  
Author(s):  
V. V. S. R. GUPTA ◽  
J. R. LAWRENCE ◽  
J. J. GERMIDA

This study investigated the impact of repeated application of S° fertilizer on microbial and biochemical characteristics of two Grey Luvisolic soils. The Waitville pasture plots received Agri-Sul at a rate of 22 or 44 kg S° ha−1 yr−1 for 5 yr, whereas the Loon River canola-summerfallow plots received single or double applications of Flow-able Sulfur (50 kg S° ha−1) or Agri-Sul (100 kg S° ha−1). Application of S° fertilizer significantly decreased the pH in both soils. Organic C declined in S°-treated plots of the Waitville soil, and there was a narrowing of C:N:S ratios in both soils. Application of S° fertilizer significantly increased the total S, HI-S and sulfate sulfur levels of both soils. There was a 29–45% and 2–51% decline in microbial biomass carbon content due to S° fertilizer application in Waitville and Loon River soils, respectively. Repeated application of S° also resulted in a decline in respiration, dehydrogenase, urease, alkaline phosphatase and arylsulfatase activities, along with populations of protozoa, algae and nitrifiers in both soils. Significant correlations observed among related characteristics further emphasized the treatment effects. These results indicate that the impact of repeated application of S° fertilizer on microbial biomass and activity should be considered when recommending S° as a fertilizer for sulfur-deficient soils. Key words: Sulfur (elemental), microbial biomass, dehydrogenase, urea, phosphomonoesterases, arylsulfatase

Soil Research ◽  
2008 ◽  
Vol 46 (2) ◽  
pp. 141 ◽  
Author(s):  
Joginder Kaur ◽  
O. P. Choudhary ◽  
Bijay-Singh

Long-term sodic-water irrigation may adversely affect the quality of soil organic carbon along with some soil properties. The extent to which the adverse effects can be ameliorated through the use of gypsum and amendments needs to be known. Soil properties and microbial biomass carbon (MBC) were studied after 14 years of sodic water (SW) irrigation and application of different levels of gypsum, farmyard manure (FYM), green manure (GM), and wheat straw (WS) to a sandy loam soil. Irrigation with SW increased pH, electrical conductivity, sodium adsorption ratio, exchangeable sodium percentage (ESP), and bulk density, and decreased final infiltration rate of soil. Application of gypsum and organic amendments reversed these trends. Decrease in MBC due to SW irrigation was from 132.5 to 44.6 mg/kg soil in the 0–75 mm soil layer and from 49.0 to 17.3 mg/kg soil in the 75–150 mm soil layer. Application of gypsum and organic amendments significantly increased MBC; GM and FYM were more effective than WS. Changes in soil ESP explained 85 and 75% variation in MBC in the unamended and organically amended SW treatments, respectively. Soil pH as additional variable improved the predictability of MBC to 96% and 77%. Irrigation with SW reduced yield of rice plus wheat by 5 t/ha. Application of gypsum and organic amendments significantly increased the rice and wheat yield; it was significantly correlated with MBC (r = 0.56**, n = 60). It confirms that MBC rather than organic C is a more sensitive indicator of environmental stresses in soils caused by long-term sodic water irrigation.


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 274 ◽  
Author(s):  
Víctor Fernández-García ◽  
Elena Marcos ◽  
Otilia Reyes ◽  
Leonor Calvo

Global change is altering fire frequency and severity in many regions across the world. In this work, we studied the impact of different frequency and severity regimes on the soil biochemical properties in burned areas with different environmental conditions. We selected three sites dominated by pine ecosystems along a Mediterranean-Transition-Oceanic climatic gradient, where we determined the fire frequency, and severity of the last wildfire. Four years after the last wildfire, we established 184 4 m2 plots. In each plot, we collected a composed soil sample from a 3 cm depth, and measured several ecological variables potentially affected by the fire frequency and severity (cover of bare soil, cover of fine and coarse plant debris, cover of vegetation, and vegetation height). From each soil sample, we analyzed the enzymatic activities corresponding to the biogeochemical cycles of carbon, nitrogen, and phosphorus (β-glucosidase, urease, and acid-phosphatase, respectively), and the microbial biomass carbon. The results indicated that fire frequency only played a significant role in soil biochemical properties at the Mediterranean and Transition sites. Specifically, we found that increases in frequency contributed to increased urease and phosphatase activities (at the Transition site), as well as microbial biomass carbon (at the Mediterranean and Transition sites). In relation to burn severity, we found opposite patterns when comparing the Mediterranean and Oceanic sites. Specifically, increased severity significantly decreased β-glucosidase, urease, and microbial biomass carbon at the Mediterranean site, whereas at the Oceanic one, severity significantly increased them. Burn severity also decreased microbial biomass carbon at the Transition site. Our results also indicated that, overall, fire frequency determined the studied ecological variables at the Mediterranean and Transition sites, but clear indirect effects on biochemical properties due to changes in ecological variables were not found. This study adds to the knowledge on the impact of shifts in fire regimes on soils in the current context of change.


Author(s):  
T. L. Ataikiru ◽  
G. S. C. Okpokwasili ◽  
P. O. Okerentugba

This study aimed at determining the impact of Carbofuran and Paraquat use on soil microbial biomass and microbial population as soil health index. Pot experiment, set-up as a randomized block design with replicates was done, with both pesticides applied at recommended rates for eight weeks. Twenty-four (24) soil samples were taken from the pesticides polluted soil as well as the unpolluted soil. These samples were used to assess the effect of pesticides on microbial biomass carbon (MB-C), nitrogen (MB-N) and phosphorus (MB-P). Also, microbial population (determined by aerobic spread plate count) of the pesticide-polluted soils was used as health index. The assessments were done weekly. The microbial biomass values increased from 273.48 µg/g to 293.15 µg/g (MB-C), 17.275 µg/g to 18.52 µg/g (MB-N) and 10.605 µg/g to 11.37 µg/g (MB-P) in carbofuran treated soil while increases from 277.26 µg/g to 288.365 µg/g (MB-C), 17.515 µg/g to 18.22 µg/g (MB-N) and 10.745 µg/g to 11.18 µg/g (MB-P) were observed in paraquat treated soil. The microbial counts in treated soils were within the ranges of 1.95 x 106 cfu/g to 1.03 x 107 cfu/g, 8.83 x 104 to 1.90 x 105 cfu/g, 1.08x 104 to 2.43 x 104, 1.15 x105 to 2.17 x 105 cfu/g, 1.38 x 105 to 2.22 x 105 cfu/g for total heterotrophic bacterial, fungal, actinomycetes, phosphate solubilizers, nitrifiers counts, respectively. The pesticides had no negative effects on the MB-C, MB-N, MB-P and soil microorganisms at recommended field rates, hence their use must be strictly based on these rates. These findings indicate that the relationship between soil nutrients and microbial biomass is significant in facilitating the use of microbial biomass as an important soil quality indicator.


1970 ◽  
Vol 25 (1) ◽  
pp. 21-25
Author(s):  
SM Abdur Rahman ◽  
ARM Solaiman

Microbial biomass carbon (C) and nitrogen (N) and their contribution to soil organic carbon and total N contents were assessed in soils collected from Bilashchara Tea Estate under Bangladesh Tea Research Institute (BTRI), Srimangal of Moulavibazar district, and Sripur Tea Garden under Jaintapur of Sylhet district. Microbial biomass C and N in Bila shchara Tea Estate soils varied from 90.4-144.0 and 20.5-29.0 mg/kg soil, and that of Sripur Tea Garden soils varied from 120.7-362.0 and 26.6-59.5 mg/kg soil, respectively. Within the two tea growing areas biomass C/N ratios ranged from 3.35-6.12. Relationships between biomass C and organic carbon and biomass N and total N were positively correlated. The contribution of biomass C to soil organic C was 1.23%, ranging from 0.9-1.55% and the contribution of biomass N to total N content of the soils ranged from 1.19-2.89%. Keywords: Biomass carbon (C); Biomass nitrogen (N); Organic C; Total N; Tea soilDOI: http://dx.doi.org/10.3329/bjm.v25i1.4850 Bangladesh J Microbiol, Volume 25, Number 1, June 2008, pp 21-25


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2462
Author(s):  
Muhammad Aamer ◽  
Muhammad Bilal Chattha ◽  
Athar Mahmood ◽  
Maria Naqve ◽  
Muhammad Umair Hassan ◽  
...  

Biochar application is considered an effective approach to mitigating nitrous oxide (N2O) emissions from agricultural soils. However, the mechanisms of biochar to mitigate N2O emissions from acidic red soils are still unclear. Therefore, the present study aims to underpin mechanisms associated with rice residue-based biochar in mitigating N2O emissions from acid soils. Soil treated with different rates of biochar control, from 1%, 2%, and 3%, and different soil properties, including soil pH, microbial biomass carbon (MBC), NH4+-N, NO3−-N, genes abundance (nosZ, nirK, AOA, and AOB), and enzymatic activities ((nitrate reductase (NR) and urease (UR)) were studied. The application of 3% biochar increased the soil pH (5.21–6.48), MBC (565–685 mg/kg), NO3−-N contents (24.23–44.5 mg/kg), genes abundance (nosZ, nirK, AOA, and AOB) and UR activity. The highest N2O emission (43.60 μg kg−1) was recorded and compared with the application of 1% (26.3 μg kg−1), 2% (18.33 μg kg−1), and 3% biochar (8.13 μg kg−1). Applying 3% biochar effectively reduced the N2O emission due to increased soil pH, MBC, NO3−-N contents, genes abundance (nosZ, nirK, AOA, and AOB), and weakened NH4+-N and NR activities. Therefore, increasing soil pH, genes abundance, and weakened nitrification following the addition of rice residue-based biochar can effectively reduce the N2O emissions from acidic red soils.


2000 ◽  
Vol 32 (5) ◽  
pp. 581-587 ◽  
Author(s):  
E.G. Gregorich ◽  
B.C. Liang ◽  
C.F. Drury ◽  
A.F. Mackenzie ◽  
W.B. McGill

2021 ◽  
Vol 25 (11) ◽  
pp. 34-37
Author(s):  
Anis Naushi ◽  
Ajay Kumar Arya

This investigation was aimed toward assessing the impact of heavy metals on soil microbial cycles. The impacts of lead (Pb) and cadmium (Cd) at various concentrations were researched over a time of about two months. Chloride salts of Pb and Cd were added independently and in blend to soil samples at room temperature (27ºC) in various polythene packs. Samples were taken from the sacks at about fourteen days span and estimations were taken of the microbial biomass carbon (MBC). The outcomes showed that there was a significant reduction in the microbial biomass carbon for all treated soils from the second week to the 6th week. However, on 8th week, increase in microbial biomass carbon was observed. At the 6th week, 2000mgkg-1Pb and 40mgkg-1Cd gave the main reduction (P < 0.05) in microbial biomass carbon of 98%. A critical decrease in biomass carbon in metal contaminated soil demonstrated that this parameter is a decent marker of toxicity of metals on soil microflora.


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