scholarly journals Aliphatic compounds, organic C and N and microbial biomass and its activity in long-term field experiment

2011 ◽  
Vol 51 (No. 6) ◽  
pp. 276-282 ◽  
Author(s):  
T. Šimon
Keyword(s):  
Microbial Biomass ◽  
Field Experiment ◽  
Basal Respiration ◽  
Aliphatic Compound ◽  
Hydrophobicity Index ◽  
Organic C ◽  
Aliphatic Compounds ◽  
C And N ◽  
Term Field

The content of aliphatic compounds, hydrophobicity index, organic C and N content and the microbial biomass and respiration activity were analysed in soil samples originating from different plots of a long-term field experiment (variants: nil, NPK – mineral fertilization: 64.6–100 kg/ha/year, FYM – farmyard manure and FYM + NPK) from three blocks (III, IV and B) with different crop rotation. Samples were taken from 0–200 mm layer in 2002 and 2003 (spring and autumn). The plots without any fertilization had the significantly lowest aliphatic compound content compared to variants fertilized by FYM or FYM + NPK in all the evaluated blocks in both years. The variants fertilized only by mineral NPK without any organic fertilization had the slightly increased aliphatic compound content but they did not exceed significantly the control variants in most cases. The aliphatic compound contents correlated significantly with the organic C contents in 2002 and 2003, as well. The values of the hydrophobicity index showed a similar trend like the data mentioned above. Organic manure increased the soil organic nitrogen content, similarly to the carbon content. In variants fertilized by FYM and FYM + NPK the higher microbial biomass content was found comparing to unfertilized variants. Correlations between aliphatic compound content and biomass differed in spring (2002: r = 0.065, 2003: r = 0.068) and autumn (2002: r = 0.407, 2003: r = 0.529). Organically fertilized variants had increased basal respiration, in autumn 2002 the basal respiration was higher in variants fertilized by mineral NPK, too. The highest specific respiration was recorded in the unfertilised plot in block B (autumn 2002 and 2003), where low microbial biomass exhibited high activity. Increased specific respiration was found also in plots fertilized by FYM and FYM + NPK (block III and IV, autumn samplings). Positive significant correlations between microbial biomass content and basal respiration were found in 2002 (spring: r = 0.716) and 2003 (spring: r = 0.765, autumn: r = 0.671).

scholarly journals The influence of long-term organic and mineral fertilization on soil organic matter

2008 ◽  
Vol 3 (No. 2) ◽  
pp. 41-51 ◽  
Author(s):  
T. Šimon
Keyword(s):  
Microbial Biomass ◽  
Basal Respiration ◽  
Hot Water ◽  
Microbial Biomass C ◽  
Mineral Fertilization ◽  
Respiration Activity ◽  
Organic C ◽  
Aliphatic Compounds ◽  
Control Variant

Parameters evaluating soil organic matter quantity (organic C and N content) and quality (hot water extractable C content, aliphatic compounds, microbial biomass C content, basal respiration activity) were determined in soils differently fertilized (NPK &ndash; mineral fertilization 64.6 kg N/ha/year, FYM &ndash; farmyard manure 38.6 kg N/ha/year, FYM + NPK &ndash; 103.3 kg N/ha/year) in long-term field experiment established in 1955 in Prague. Variant without any fertilization was used as a control. Nine years crop rotation (45% cereals, 33% root crops, 22% fodder crops) is practiced in this long-term experiment. Soil samples were taken from the arable layer (0&ndash;20 cm) in spring over the period of 1994&ndash;2004. Continual application of FYM and FYM + NPK increased the organic carbon content, hot water extractable C (HWC) content, aliphatic compounds content and microbial biomass C content significantly compared to control variant. Mineral fertilization (NPK) increased only organic C content significantly compared to control variant; HWC content, aliphatic compounds content and microbial biomass C content were increased not significantly. Basal respiration activity did not differ significantly between the variants but the influence of plants cropped in individual years on the basal respiration was observed. The total N content was increased significantly only in FYM + NPK variant as compared to control variant. Presence of lucerne in crop rotation contributed positively to the total nitrogen content in soil of all variants due to the symbiotic N<sub>2</sub> fixation. C:N ratio varied from 9.96 to 10.46. Significant positive relationships (r = 0.30 to 0.68; P &lt; 0.05) among the all parameters were determined with exception of basal respiration activity. The most of measured characteristics tended to be constant or slightly increase in the period of observation that shows evidence of stability of this soil management system.

Management of sugarcane harvest residues: consequences for soil carbon and nitrogen

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 13 ◽  
Author(s):  
Fiona A. Robertson ◽  
Peter J. Thorburn
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Microbial Activity ◽  
Soil N ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil Microbial ◽  
C And N

The Australian sugar industry is moving away from the practice of burning the crop before harvest to a system of green cane trash blanketing (GCTB). Since the residues that would have been lost in the fire are returned to the soil, nutrients and organic matter may be accumulating under trash blanketing. There is a need to know if this is the case, to better manage fertiliser inputs and maintain soil fertility. The objective of this work was to determine whether conversion from a burning to a GCTB trash management system is likely to affect soil fertility in terms of C and N. Indicators of short- and long-term soil C and N cycling were measured in 5 field experiments in contrasting climatic conditions. The effects of GCTB varied among experiments. Experiments that had been running for 1–2 years (Harwood) showed no significant trash management effects. In experiments that had been running for 3–6 years (Mackay and Tully), soil organic C and total N were up to 21% greater under trash blanketing than under burning, to 0.10 or 0.25 m depth (most of this effect being in the top 50 mm). Soil microbial activity (CO2 production) and soil microbial biomass also increased under GCTB, presumably as a consequence of the improved C availability. Most of the trash C was respired by the microbial biomass and lost from the system as CO2. The stimulation of microbial activity in these relatively short-term GCTB systems was not accompanied by increased net mineralisation of soil N, probably because of the greatly increased net immobilisation of N. It was calculated that, with standard fertiliser applications, the entire trash blanket could be decomposed without compromising the supply of N to the crop. Calculations of possible long-term effects of converting from a burnt to a GCTB production system suggested that, at the sites studied, soil organic C could increase by 8–15%, total soil N could increase by 9–24%, and inorganic soil N could increase by 37 kg/ha.year, and that it would take 20–30 years for the soils to approach this new equilibrium. The results suggest that fertiliser N application should not be reduced in the first 6 years after adoption of GCTB, but small reductions may be possible in the longer term (>15 years).

scholarly journals The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization

2008 ◽  
Vol 54 (No. 11) ◽  
pp. 463-470 ◽  
Author(s):  
V. Nedvěd ◽  
J. Balík ◽  
J. Černý ◽  
M. Kulhánek ◽  
M. Balíková
Keyword(s):  
Field Experiment ◽  
N Fertilization ◽  
Hot Water ◽  
Control Treatment ◽  
Organic N ◽  
Total N ◽  
C And N ◽  
N Compounds ◽  
Term Field

Content of N and C in soil were investigated in a long-term field experiment under different systems of N fertilization. Chernozem and Cambisol were extracted using hot water (N<sub>hws</sub>, C<sub>hws</sub>) and 0.01M CaCl<sub>2</sub> (N<sub>CaCl2</sub>, C<sub>DOC</sub>). The C<sub>t</sub>/N<sub>t</sub> ratio in Chernozem was 9.6:1 and in Cambisol 6.1:1. The lowest C<sub>t</sub>/N<sub>t</sub> ratio in both experiments was found in the control treatment. Results showed that C and N compounds are less stable in Cambisol, which leads to a higher rate of mineralization. In the Chernozem, N<sub>hws</sub> formed 3.66% from the total N content in the soil whereas N<sub>CaCl2</sub> formed only 0.82%. C<sub>hws</sub> formed 2.98% and C<sub>DOC</sub> 0.34% from total C content. Cambisol contains 4.81% of N<sub>hws</sub> and 0.84% of N<sub>CaCl2</sub> from the total N amount and 5.76% of C<sub>hws</sub> and 0.70% of C<sub>DOC</sub> from the total C content, respectively. Nitrogen extracted by 0.01M CaCl2 formed only 22.4% of N extractable by hot water in Chernozem and 17.5% in Cambisol. The lowest C/N ratios were obtained after the CaCl<sub>2</sub> extraction (3.0–6.2:1). The application of manure increased the content of soil organic N and C compared to the sewage sludge treatments.

KMnO4 determination of active carbon for laboratory routines: three long-term field experiments in Austria

Soil Research ◽  
2015 ◽  
Vol 53 (2) ◽  
pp. 190 ◽  
Author(s):  
M. Tatzber ◽  
N. Schlatter ◽  
A. Baumgarten ◽  
G. Dersch ◽  
R. Körner ◽  
...  
Keyword(s):  
Field Experiment ◽  
Field Experiments ◽  
Cropping Systems ◽  
Organic Amendments ◽  
Sodium Oxalate ◽  
Tillage Systems ◽  
Organic C ◽  
Significant Difference ◽  
Term Field

Recent studies show that a labile soil carbon (C) fraction determined with potassium permanganate (KMnO4) reflects the type of soil management. The present study combines the method for determining the active C (AC) pool with an alternative titration of the 0.02 m KMnO4 solution with sodium oxalate (Na2C2O4) for routine laboratory analyses. Three long-term field experiments investigated: (i) different cropping systems and 14C-labelled organic amendments, (ii) three different tillage systems, and (iii) the application of four different kinds of compost. The results showed the depletion of AC in the permanent bare-fallow system of the 14C-labelled field experiment. When calculating the ratio AC/total organic C (TOC), the depletion of the AC/TOC curve reflected a priming effect, in accord with previous work. We obtained significant positive correlations of AC with TOC, total nitrogen (Nt), humic acid-C and remaining 14C-labelled material. The AC in the tillage systems experiment was significantly (P < 0.05) different between all three tillage treatments at 0–10 cm depth, and the ratio AC/TOC also revealed a significant difference between minimum and conventional tillage treatments at 10–20 cm. For the compost field experiment, significant differences occurred between plots fertilised solely with N and plots receiving organic amendments. The AC/TOC ratio of the sewage sludge amendment was significantly lower than in all other systems. Correlations of AC with TOC for all samples of the different long-term field experiments revealed different behaviours in different soil types. The correlations of AC with Nt showed higher coefficients than with TOC. The applied methodology has a potential for sensitive and reliable detections of differences in soil organic matter characteristics.

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