Short-term C and N dynamics in a soil amended with pig slurry and barley straw: a field experiment

2001 ◽  
Vol 81 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Martin H Chantigny ◽  
Philippe Rochette ◽  
Denis A Angers
Keyword(s):  
Microbial Biomass ◽  
Field Experiment ◽  
Crop Residues ◽  
Barley Straw ◽  
Microbial Biomass C ◽  
N Availability ◽  
Pig Slurry ◽  
Soil N ◽  
Short Term ◽  
C And N

Interactions between animal slurries and crop residues can impact on soil N availability during decomposition. Our objective was to study the short-term decomposition of pig slurry and barley straw incorporated alone or in combination. A field experiment was conducted on a sandy loam unamended (control) or amended with 60 m3 ha–1 pig slurry (PS) or 4 Mg ha–1 barley straw (BS), or both (PSBS). Surface CO2 and N2O fluxes, soil water content and temperature, microbial biomass C, and NO3− and NH4+ contents were monitored during 28 d in the 0- to 20-cm soil layer. Large CO2 fluxes occurred during the first 4 h of the experiment in slurry-amended plots that were attributed to carbonate dissociation when slurry was mixed to the soil. Specific respiration activity (ratio of CO2-C fluxes-to-microbial biomass C) was increased in slurry-amended soils for the first 7 d, likely due to the rapid oxidation of volatile fatty acids present in slurry. After 28 d, 26% more C had been evolved in PSBS than the sum of C released from PS and BS, indicating a synergistic interaction during decomposition of combined amendments. Adding straw caused a net but transient immobilisation of soil N, especially in PSBS plots where 36% of slurry-added NH4+ was immobilised after 3 d. Slurry-NH4+ was rapidly nitrified (within 10 d), but N2O production was not a significant source of N loss during this study, representing less than 0.3% of slurry-added NH4+. Nevertheless, about twice the amount of N2O was produced in PS than in PSBS after 28 d, reflecting lower soil N availability in the presence of straw. Our study clearly illustrates the strong interaction existing between soil C and N cycles under field conditions as slurry mineral N appeared to stimulate straw-C mineralisation, whereas straw addition caused a net immobilisation of slurry N. Key words: Animal slurry, crop residues, C-N relationships, organic amendments

Carbon and nitrogen mineralization in cultivated and grassland soils in subtropical Queensland

Soil Research ◽  
1993 ◽  
Vol 31 (5) ◽  
pp. 611 ◽  
Author(s):  
FA Robertson ◽  
RJK Myers ◽  
PG Saffigna
Keyword(s):  
Microbial Biomass ◽  
Specific Activity ◽  
Continuous Cultivation ◽  
Microbial Biomass C ◽  
N Availability ◽  
Grassland Soils ◽  
Prolonged Incubation ◽  
Cultivated Soil ◽  
C And N ◽  
Cultivated Soils

Availability of N in the clay soils of the brigalow region of Queensland declines rapidly under sown pasture, but under continuous cultivation and cropping, it remains high enough to supply the needs of cereal crops for at least 20 years. The aim of this work was to determine whether the low availability of N under pasture was due to low microbial activity or to rapid re-immobilization of mineralized N. Microbial biomass C and N (0-28 cm) were 420 and 68 �g g-1 respectively in pasture soil but only 214 and 41 �g g-1 respectively in cultivated soil. Pasture soils respired more CO2 (Cresp) and mineralized less N (Nmin) than cultivated soils (219 and 93 �g C g-1 and 3.1 and 5.9 �g N g-1 respectively) during 10-day incubations over 2 years. Increased Crop under pasture was due to an increase in the amount rather than the specific activity of the microbial biomass. The smaller Nmin in grassland soils was due to more rapid immobilization rather than reduced gross mineralization of N, as the ratio Cresp : Nmin was larger and the ratio Nmin :biomass N was smaller in the grassland than in the cultivated soil. On prolonged incubation. with progressive loss of CO2 through respiration, Nmin increased and N immobilization decreased in the grassland soils. Prolonged incubation of the cultivated soils reduced Nmin because of C limitation. The above patterns of C and N mineralization in the grassland and cultivated soils helped to explain the differences in N availability in the two systems.

Soil microbial biomass, C and N mineralization, and enzyme-activities in a hill pasture - Influence of grazing management

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 943 ◽  
Author(s):  
DJ Ross ◽  
TW Speir ◽  
HA Kettles ◽  
KR Tate ◽  
AD Mackay
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
N Mineralization ◽  
Microbial Biomass C ◽  
N Availability ◽  
Net N Mineralization ◽  
High Background ◽  
C And N Mineralization ◽  
C And N ◽  
Legume Growth

Grazing and fertilizer management practices are of prime importance for maintaining summer-moist hill pastures of introduced grasses and clovers in New Zealand for sheep and cattle production. The influence of withholding grazing (a pastoral fallow) from spring to late summer on microbial biomass, C and N mineralization, and enzyme activities was investigated in a Typic Dystrochrept soil from unfertilized and fertilized (rock phosphate and elemental S) low-fertility pastures at a temperate hill site. The fallow increased pasture but not legume growth in the following year in the unfertilized treatment, but had no effect on pasture or legume growth in fertilized plots. High background levels of the biochemical propel-ties examined, and very variable rates of N mineralization, complicated data interpretation. Extractable-C concentration and CO2-C production were enhanced at the completion of the fallow. Increases in net N mineralization (14-56 days incubation), following initial immobilization, after the fallow were clearly indicated in the unfertilized treatment, but were less distinct, in the fertilized treatment. The fallow had no detectable influence on the concentrations of total C and N or microbial C and P, or on invertase, phosphodiesterase and sulfatase activities. Some small changes in microbial N and an increased proportion of bacteria in the microbial population were, however, suggested. Results are consistent with the concept of fallowing giving a short-term increase in pools of readily decomposable soil organic matter. Generally, the changes that did occur in these soil biochemical properties are, with the partial exception of increased N availability, unlikely to have had any pronounced impact on subsequent pasture performance.

scholarly journals Short-Term Effect of Nitrogen Fertilization on Carbon Mineralization during Corn Residue Decomposition in Soil

Nitrogen ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 444-460
Author(s):  
Tanjila Jesmin ◽  
Dakota T. Mitchell ◽  
Richard L. Mulvaney
Keyword(s):  
Microbial Biomass ◽  
C:N Ratio ◽  
Carbon Mineralization ◽  
N Fertilization ◽  
Co2 Production ◽  
Microbial Biomass C ◽  
N Availability ◽  
Soil C ◽  
Residue Decomposition ◽  
C And N

The effect of N fertilization on residue decomposition has been studied extensively; however, contrasting results reflect differences in residue quality, the form of N applied, and the type of soil studied. A 60 d laboratory incubation experiment was conducted to ascertain the effect of synthetic N addition on the decomposition of two corn (Zea mays L.) stover mixtures differing in C:N ratio by continuous monitoring of CO2 emissions and periodic measurement of microbial biomass and enzyme activities involved in C and N cycling. Cumulative CO2 production was greater for the high than low N residue treatment, and was significantly increased by the addition of exogenous N. The latter effect was prominent during the first month of incubation, whereas N-treated soils produced less CO2 in the second month, as would be expected due to more rapid substrate depletion from microbial C utilization previously enhanced by greater N availability. The stimulatory effect of exogenous N was verified with respect to active biomass, microbial biomass C and N, and cellulase and protease activities, all of which were significantly correlated with cumulative CO2 production. Intensive N fertilization in modern corn production increases the input of residues but is not conducive to soil C sequestration.

EFFECT OF CROP ROTATION AND FERTILIZATION ON SOME BIOLOGICAL PROPERTIES OF A LOAM IN SOUTHWESTERN SASKATCHEWAN

1984 ◽  
Vol 64 (3) ◽  
pp. 355-367 ◽  
Author(s):  
V. O. BIEDERBECK ◽  
C. A. CAMPBELL ◽  
R. P. ZENTNER
Keyword(s):  
Microbial Biomass ◽  
Crop Residues ◽  
Biological Properties ◽  
Organic N ◽  
Microbial Biomass C ◽  
Rotation Length ◽  
Continuous Type ◽  
Mineralizable N ◽  
P Fertilizer ◽  
Potentially Mineralizable N

Effects of rotation length, fallow-substitute crops, and N and P fertilizer on some physical and biological properties of a Brown Chernozemic loam in southwestern Saskatchewan were determined over a period of 16 yr. After 12 yr, the erodible fraction in the top 15 cm of soil (i.e., < 0.84 mm) was inversely related to trash conserved and thus rotation length. Soil organic N (in the top 15 cm) increased from 0.18 to 0.20% in continuous-type rotations receiving an average 32 kg N∙ha−1∙yr−1 and adequate P, but it did not increase in continuous wheat receiving P only, nor in fallow rotations, except the one that included fall rye (Secale cereale L.). This N increase was credited partly to fertilizer and partly to more efficient use and cycling of subsoil NO3-N via plant roots and crop residues. After 10 yr, well-fertilized continuous-type rotations had a 13% greater C content than fallow rotations and continuous wheat receiving only P. In the top 7.5 cm of soil under the four rotations examined in detail, bacterial numbers were lowest in fallow-wheat, intermediate in fallow-wheat-wheat, higher in continuous wheat receiving N and P, and highest in continuous wheat receiving only P. Similarly, microbial biomass C in these four rotations was 180, 226, 217 and 357 kg∙ha−1; biomass N was 52, 65, 54 and 72 kg∙ha−1; and biomass C/N ratios were 3.4, 3.5, 4.1 and 5.1, respectively. Differences in biomass C/N, respiration rates and numbers of bacteria, actinomycetes and yeasts indicated both quantitative and qualitative microbial changes and reflected increasing rotation length and differences in fertility. Potentially mineralizable N (No) was 192 kg∙ha−1 for adequately fertilized continuous wheat, and exceeded No in fallow-wheat by 45%, in fallow-wheat-wheat by 17% and in continuous wheat receiving only P by 25%. The latter rotation contained a large but fairly inactive microbial population. We concluded that land degradation caused by frequent summerfallowing can be arrested and the decline in amount and quality of organic matter reversed by use of available agronomic technology. Key words: Microbial biomass, microbial activity, potentially mineralizable N, respiration, soil erodibility

scholarly journals The Influence of Selected Meteorological Factors on Microbial Biomass and Mineralization of Two Organic Fertilizers

2011 ◽  
Vol 39 (1) ◽  
pp. 107
Author(s):  
Mignon S. SANDOR ◽  
Traian BRAD ◽  
Aurel MAXIM ◽  
Constantin TOADER
Keyword(s):  
Biological Activity ◽  
Microbial Biomass ◽  
Soil Ph ◽  
Soil Microbial Biomass ◽  
Organic Fertilizers ◽  
Barley Straw ◽  
Short Term ◽  
Soil Microbial ◽  
Fertilized Soil ◽  
Mineralization Processes

A mesocosm study was conducted in order to evaluate the effects of short-term rainfall and temperature variation on soil microbial biomass and bacteria to fungi ratio. In addition, the relation between the decomposition process of two organic fertilizers, cattle manure and barley straw, and the activity of soil microbial biomass was also studied. In order to assess the effect of biological activity on soil fertility the dynamics of soil pH, N-NO3-, N-NH4+, Corg and Nt during plant growing season was measured. The results suggest that short-term variation of climate had a significant effect on microbial biomass with dry periods distinguished by a reduced microbial biomass compared to wet periods. The ratio bacteria to fungi seems also to be sensitive to variations in rainfall and temperature regime, however further studies are required to draw a definitive conclusion. Regarding the type of fertilizer used, the straw treatments showed higher microbial biomass than the manure treatments, but higher decomposition rate was observed in manure fertilized soil. The effect of soil biological activity on soil pH was limited for both manure and straw treatments while the changes of the soil nitrate amounts are related to the microbial biomass. The study indicates that nitrate immobilization and mineralization processes are influenced by meteorological conditions and microbial biomass dynamics. In contrast, soil organic carbon and total nitrogen did not seem to be affected by variations in temperature, rainfall and microbial activity.

Distribution of carbon and nitrogen in a long-term cropping system and permanent pasture system

1993 ◽  
Vol 44 (6) ◽  
pp. 1323 ◽  
Author(s):  
FA Robertson ◽  
RJK Myers ◽  
PG Saffigna
Keyword(s):  
Microbial Biomass ◽  
Crop Residues ◽  
Perennial Grass ◽  
Cropping System ◽  
N Availability ◽  
Continuous Cropping ◽  
Organic C ◽  
Soil Microbial ◽  
Permanent Pasture ◽  
Standing Dead

Nitrogen (N) limitation to productivity of sown perennial grass pastures on the brigalow lands of S.E. Queensland contrasts with adequate N supply to annual crops grown on the same soil. In order to understand this anomaly, the distribution of N and carbon (C) under permanent green panic pasture and under continuous cropping with grain sorghum was compared in an 18 month field study. Total soil N and organic C (0-10 cm) were, respectively, 0.37 and 3.20% under green panic and 0.23 and 2.31% under sorghum. Soil microbial biomass (0-28 cm) contained 246 kg N and 1490 kg C ha-1 under green panic and 147 kg N and 744 kg C ha-1 under sorghum. Enhanced microbial growth under pasture was attributed to the continuous input of available C from surface litter and roots. The C/N ratio of pasture residues was high (greater than 50) and conducive to immobilization of N. Availability of N under pasture was further reduced by approximately 50% of plant N being immobilized in standing dead tissue. Under sorghum, the microbial biomass was well supplied with N, but was limited by C availability. The soil under sorghum received a single large C input when crop residues were returned after harvest. The differences in N availability, and hence productivity, of these soils under cropping and permanent pasture were due primarily to differences in the timing and quality of C inputs.

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