A comparison of the organic matter, biomass, adenosine triphosphate and mineralizable nitrogen contents of ploughed and direct-drilled soils

1981 ◽  
Vol 97 (3) ◽  
pp. 713-721 ◽  
Author(s):  
D. S. Powlson ◽  
D. S. Jenkinson
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Field Experiments ◽  
Microbial Biomass Carbon ◽  
Total Carbon ◽  
Biomass Carbon ◽  
Carbon And Nitrogen ◽  
Significant Difference ◽  
Mineralizable Nitrogen

SUMMARYSoil samples were taken from four field experiments on the growth of cereals in direct-drilled and in mouldboard-ploughed soil. When sampled, one of the experiments had run for 5 years, one for 6, one for 8 and one for 10 years. Sampling was to just below plough depth and was done on an ‘equivalent depth’ basis, i.e. the more compact direct-drilled plots were sampled more shallowly than the ploughed plots in such a way that both samples represented the same weight of soil per unit area. No significant differences in total nitrogen or in total organic carbon were observed between cultivation treatments at any of the four sites.In three of the four sites, there was no significant difference in microbial biomass carbon, adenosine 5'-triphosphate (ATP), or mineralizable nitrogen between directdrilled and ploughed soils. In the fourth, which contained more clay than the others, there was slightly more biomass carbon and ATP in the direct-drilled soil. As microbial biomass carbon (or ATP, which is closely correlated with microbial biomass carbon) responds more rapidly to changes in management than do total carbon and nitrogen, a change in biomass carbon should provide early warning of changes in soil organic matter, long before changes in total carbon and nitrogen become measurable. That no such change was observed, with one partial exception, is evidence that a change from traditional methods of cultivation to direct drilling has little effect on soil organic matter other than altering its distribution in the soil profile.

scholarly journals Evolution of Soil Biochemical Parameters in Rainfed Crops: Effect of Organic and Mineral Fertilization

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Marta M. Moreno ◽  
Carmen Moreno ◽  
Carlos Lacasta ◽  
Ramón Meco
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Biochemical Parameters ◽  
Crop Residues ◽  
Microbial Biomass Carbon ◽  
Cropping System ◽  
Biomass Carbon ◽  
Biological Fixation ◽  
Mineral Fertilization

In organic farming, crop fertilization is largely based on the decomposition of organic matter and biological fixation of nutrients. It is therefore necessary to develop studies conducted to know and understand the soil biological processes for the natural nutrient supplies. The effect of three fertilizer managements (chemical with synthetic fertilizers, organic with 2500 kg compost ha−1, and no fertilizer) in a rainfed crop rotation (durum wheat-fallow-barley-vetch as green manure) on different soil biochemical parameters in semi-arid conditions was investigated. Soil organic matter, microbial biomass carbon, organic matter mineralization, CO2production-to-ATP ratio, and NO3-N content were analysed. Fertilization was only applied to cereals. The results showed the scarce effect of the organic fertilization on soil quality, which resulted more dependent on weather conditions. Only soil organic matter and NO3-N were affected by fertilization (significantly higher in the inorganic treatment, 1.28 g 100 g−1and 17.3 ppm, resp.). Soil organic matter was maintained throughout the study period by the inclusion of a legume in the cropping system and the burying of crop residues. In fallow, soil microbial biomass carbon increased considerably (816 ng g−1), and NO3-N at the end of this period was around 35 ppm, equivalent to 100 kg N ha−1.

scholarly journals Soil CO2 emission and soil attributes associated with the microbiota of a sugarcane area in southern Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mara Regina Moitinho ◽  
Daniel De Bortoli Teixeira ◽  
Elton da Silva Bicalho ◽  
Alan Rodrigo Panosso ◽  
Antonio Sergio Ferraudo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
16S Rrna ◽  
Spatial Variability ◽  
Enzymatic Activity ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Soil Attributes ◽  
Dry Soil

AbstractThe spatial structure of soil CO2 emission (FCO2) and soil attributes are affected by different factors in a highly complex way. In this context, this study aimed to characterize the spatial variability patterns of FCO2 and soil physical, chemical, and microbiological attributes in a sugarcane field area after reform activities. The study was conducted in an Oxisol with the measurement of FCO2, soil temperature (Ts), and soil moisture (Ms) in a regular 90 × 90-m grid with 100 sampling points. Soil samples were collected at each sampling point at a depth of 0–0.20 m to determine soil physical (density, macroporosity, and microporosity), particle size (sand, silt, and clay), and chemical attributes (soil organic matter, pH, P, K, Ca, Mg, Al, H + Al, cation exchange capacity, and base saturation). Geostatistical analyses were performed to assess the spatial variability and map soil attributes. Two regions (R1 and R2) with contrasting emission values were identified after mapping FCO2. The abundance of bacterial 16S rRNA, pmoA, and nifH genes, determined by real-time quantitative PCR (qPCR), enzymatic activity (dehydrogenase, urease, cellulase, and amylase), and microbial biomass carbon were determined in R1 and R2. The mean values of FCO2 (2.91 µmol m−2 s−1), Ts (22.6 °C), and Ms (16.9%) over the 28-day period were similar to those observed in studies also conducted under Oxisols in sugarcane areas and conventional soil tillage. The spatial pattern of FCO2 was similar to that of macropores, air-filled pore space, silt content, soil organic matter, and soil carbon decay constant. No significant difference was observed between R1 and R2 for the copy number of bacterial 16S rRNA and nifH genes, but the results of qPCR for the pmoA gene presented differences (p < 0.01) between regions. The region R1, with the highest FCO2 (2.9 to 4.2 µmol m−2 s−1), showed higher enzymatic activity of dehydrogenase (33.02 µg TPF g−1 dry soil 24 h−1), urease (41.15 µg NH4–N g−1 dry soil 3 h−1), amylase (73.84 µg glucose g−1 dry soil 24 h−1), and microbial biomass carbon (41.35 µg C g−1 soil) than R2, which had the lowest emission (1.9 to 2.7 µmol m−2 s−1). In addition, the soil C/N ratio was higher in R2 (15.43) than in R1 (12.18). The spatial pattern of FCO2 in R1 and R2 may not be directly related to the total amount of the microbial community (bacterial 16S rRNA) in the soil but to the specific function that these microorganisms play regarding soil carbon degradation (pmoA).

scholarly journals The changes in microbial biomass C and N in long-term field experiments

2008 ◽  
Vol 54 (No. 5) ◽  
pp. 212-218 ◽  
Author(s):  
J. Černý ◽  
J. Balík ◽  
M. Kulhánek ◽  
V. Nedvěd
Keyword(s):  
Microbial Biomass ◽  
Crop Rotation ◽  
Field Experiments ◽  
Microbial Biomass Carbon ◽  
Organic Fertilizers ◽  
Microbial Biomass C ◽  
Biomass Carbon ◽  
Microbial Biomass Nitrogen ◽  
Carbon And Nitrogen ◽  
C And N

Microbial biomass nitrogen and carbon were studied in long-term field experiments with continuous cultivation of silage maize and with crop rotation. A positive effect of organic fertilizers on the microbial biomass nitrogen and the carbon content in soil was observed. Statistically significant effect of organic fertilizers on the higher content of microbial biomass C and N was established in the first year after their application. During the application the content of microbial biomass carbon and nitrogen decreased, but there were higher biomass C and N contents compared to control, even without statistical significance. A negative effect on microbial biomass carbon and nitrogen content in soil came from the application of mineral nitrogen fertilizers in experiments with maize. Statistically significant effect of mineral N fertilizers was observed after their application. In the course of the N fertilizers application the content of microbial biomass carbon and nitrogen was lower than control. No statistically significant effects of mineral nitrogen fertilizers on the microbial biomass nitrogen and carbon content were observed in field experiments with crop rotation over the eight years of experiment duration. The higher effect of mineral and organic fertilizers application on the changes in microbial biomass C and N was reported in experiments with continuous cultivation of maize compared to experiments with crop rotation.

scholarly journals Reviews and syntheses: Soil resources and climate jointly drive variations in microbial biomass carbon and nitrogen in China's forest ecosystems

2015 ◽  
Vol 12 (22) ◽  
pp. 6751-6760 ◽  
Author(s):  
Z. H. Zhou ◽  
C. K. Wang
Keyword(s):  
Microbial Biomass ◽  
Forest Ecosystems ◽  
Microbial Biomass Carbon ◽  
Mean Annual Temperature ◽  
Biomass Carbon ◽  
Large Variability ◽  
Soil Resources ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
Microbial Quotient

Abstract. Microbial metabolism plays a key role in regulating the biogeochemical cycle of forest ecosystems, but the mechanisms driving microbial growth are not well understood. Here, we synthesized 689 measurements on soil microbial biomass carbon (Cmic) and nitrogen (Nmic) and related parameters from 207 independent studies published up to November 2014 across China's forest ecosystems. Our objectives were to (1) examine patterns in Cmic, Nmic, and microbial quotient (i.e., Cmic / Csoil and Nmic / Nsoil rates) by climate zones and management regimes for these forests; and (2) identify the factors driving the variability in the Cmic, Nmic, and microbial quotient. There was a large variability in Cmic (390.2 mg kg−1), Nmic (60.1 mg kg−1, Cmic : Nmic ratio (8.25), Cmic / Csoil rate (1.92 %), and Nmic / Nsoil rate (3.43 %) across China's forests. The natural forests had significantly greater Cmic (514.1 mg kg−1 vs. 281.8 mg kg−1) and Nmic (82.6 mg kg−1 vs. 39.0 mg kg−1) than the planted forests, but had less Cmic : Nmic ratio (7.3 vs. 9.2) and Cmic / Csoil rate (1.7 % vs. 2.1 %). Soil resources and climate together explained 24.4–40.7 % of these variations. The Cmic : Nmic ratio declined slightly with Csoil : Nsoil ratio, and changed with latitude, mean annual temperature and precipitation, suggesting a plasticity of microbial carbon-nitrogen stoichiometry. The Cmic / Csoil rate decreased with Csoil : Nsoil ratio, whereas the Nmic / Nsoil rate increased with Csoil : Nsoil ratio; the former was influenced more by soil resources than by climate, whereas the latter was influenced more by climate. These results suggest that soil microbial assimilation of carbon and nitrogen are jointly driven by soil resources and climate, but may be regulated by different mechanisms.

scholarly journals Soil resources and climate jointly drive variations in microbial biomass carbon and nitrogen in China's forest ecosystems

2015 ◽  
Vol 12 (14) ◽  
pp. 11191-11216 ◽  
Author(s):  
Z. H. Zhou ◽  
C. K. Wang
Keyword(s):  
Microbial Biomass ◽  
Microbial Growth ◽  
Forest Ecosystems ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Large Variability ◽  
Soil Resources ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
Microbial Quotient

Abstract. Microbial metabolism plays a key role in regulating the biogeochemical cycle of forest ecosystems, but the mechanisms driving microbial growth are not well understood. Here, we synthesized 689 measurements on soil microbial biomass carbon (Cmic) and nitrogen (Nmic) and related parameters from 207 independent studies published during the past 15 years across China's forest ecosystems. Our objectives were to (1) examine patterns in Cmic, Nmic, and microbial quotient (i.e., Cmic / Csoil and Nmic / Nsoil rates) by climate zones and management regimes for these forests; and (2) identify the factors driving the variability in the Cmic, Nmic, and microbial quotient. There was a large variability in Cmic (390.2 mg kg−1), Nmic (60.1 mg kg−1), Cmic : Nmic ratio (8.25), Cmic / Csoil rate (1.92 %), and Nmic / Nsoil rate (3.43 %) across China's forests, with coefficients of variation varying from 61.2 to 95.6 %. The natural forests had significantly greater Cmic and Nmic than the planted forests, but had less Cmic : Nmic ratio and Cmic / Csoil rate. Soil resources and climate together explained 24.4–40.7 % of these variations. The Cmic : Nmic ratio declined slightly with the Csoil : Nsoil ratio, and changed with latitude, mean annual temperature and precipitation, suggesting a plastic homeostasis of microbial carbon-nitrogen stoichiometry. The Cmic / Csoil and Nmic / Nsoil rates were responsive to soil resources and climate differently, suggesting that soil microbial assimilation of carbon and nitrogen be regulated by different mechanisms. We conclude that soil resources and climate jointly drive microbial growth and metabolism, and also emphasize the necessity of appropriate procedures for data compilation and standardization in cross-study syntheses.

scholarly journals Ratio of soil microbial biomass carbon to soil organic carbon in Himalayan rangeland

2018 ◽  
Vol 2 ◽  
pp. 96-101
Author(s):  
Dil Kumar Limbu ◽  
Madan Koirala
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Soil Microbial Biomass Carbon ◽  
Microbial Carbon

The soil microbial biomass carbon to soil organic carbon ratio is a useful measure to monitor soil organic matter and serves as a sensitive index than soil organic carbon alone. Thus, the objective of this study is to identify and quantify the present status of ratio of soil microbial biomass carbon to soil organic carbon in Himalayan rangeland and to make recommendations for enhancing balance between microbial carbon and organic carbon of the soil. To meet the aforementioned objective, a field study was conducted from 2011 to 2013 following the Walkley-Black, Chromic acid wet oxidation method, and chloroform fumigation method for analysis of microbial carbon and organic carbon respectively. The study showed that the heavily grazed plot had significantly less value of ratio than occasionally grazed and ungrazed plots. The ratio was significantly high on legume seeding plot compared to nonlegume plot, but the ratio was independent of soil depth. Soil microbial biomass appeared to be more responsive than soil organic matter.

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