scholarly journals Implications of carbon saturation model structure for simulated nitrogen mineralization dynamics

2014 ◽  
Vol 11 (6) ◽  
pp. 9667-9695 ◽  
Author(s):  
C. M. White ◽  
A. R. Kemanian ◽  
J. P. Kaye
Keyword(s):  
Soil Properties ◽  
N Mineralization ◽  
Storage Capacity ◽  
Clay Content ◽  
N Cycling ◽  
Transfer Efficiency ◽  
Net N Mineralization ◽  
Saturation Ratio ◽  
Carbon Saturation ◽  
C And N

Abstract. Carbon (C) saturation theory suggests that soils have a~limited capacity to stabilize organic C and that this capacity may be regulated by intrinsic soil properties such as clay content and mineralogy. While C saturation theory has advanced our ability to predict soil C stabilization, we only have a weak understanding of how C saturation affects N cycling. In biogeochemical models, C and N cycling are tightly coupled, with C decomposition and respiration driving N mineralization. Thus, changing model structures from non-saturation to C saturation dynamics can change simulated N dynamics. Carbon saturation models proposed in the literature calculate a theoretical maximum C storage capacity of saturating pools based on intrinsic soil properties, such as clay content. The extent to which current C stocks fill the storage capacity of the pool is termed the C saturation ratio, and this ratio is used to regulate either the efficiency or the rate of C transfer from donor to receiving pools. In this study, we evaluated how the method of implementing C saturation and the number of pools in a model affected net N mineralization from decomposing plant residues. In models that use the C saturation ratio to regulate transfer efficiency, C saturation affected N mineralization, while in those in which the C saturation ratio regulates transfer rates, N mineralization was independent of C saturation. When C saturation ratio regulates transfer efficiency, as the saturation ratio increases, the threshold C : N ratio at which positive net N mineralization occurs also increases because more of the C in the residue is respired. In a single-pool model where C saturation ratio regulated the transfer efficiency, predictions of N mineralization from residue inputs were unrealistically high, missing the cycle of N immobilization and mineralization typically seen after the addition of high C : N inputs to soils. A more realistic simulation of N mineralization was achieved simply by adding a second pool to the model to represent short-term storage and turnover of C and N in microbial biomass. These findings increase our understanding of how to couple C saturation and N mineralization models, while offering new hypotheses about the relationship between C saturation and N mineralization that can be tested empirically.

Carbon and nitrogen mineralization in soil amended with non-tabletized and tabletized poultry manure

2000 ◽  
Vol 80 (2) ◽  
pp. 271-276 ◽  
Author(s):  
T. Paré ◽  
H. Dinel ◽  
M. Schnitzer
Keyword(s):  
Nitrogen Mineralization ◽  
N Mineralization ◽  
Organic Fertilizer ◽  
Carbon Mineralization ◽  
Poultry Manure ◽  
Net N Mineralization ◽  
N Accumulation ◽  
Suitable Alternative ◽  
C And N Mineralization ◽  
C And N

The recycling of poultry (Gallus gallus domesticus) manure (PM) needs to be done in a manner that will not only improve soil physical, chemical and biological properties but also minimize environmental risks. Untreated PM is more difficult to handle and more expensive to apply than granular fertilizers; the application of PM in the form of tablets may be a suitable alternative. It is necessary to determine whether C and N mineralization in tabletized PM (T-PM) differs from non-tabletized PM (NT-PM). Net C and N mineralization from a Brandon loam soil (Typic Endoaquoll) amended with NT-PM and T-PM, were measured in an incubation study at 25 °C. After 60 d of incubation, about 62 and 77% of total PM carbon was mineralized in NT-PM and T-PM amended soils, respectively. Carbon mineralization was not stimulated by the addition of PM tablets containing NPK to soil, while in soils mixed with NT-PM + NPK, soil respiration was reduced. Net N mineralization was similar in soils amended with T-PM and NT-PM, although changes in ammonium (NH4+–N) concentrations during incubation differed. Generally more NH4+–N accumulated in soil amended with T-PM and T-PM + NPK than with NT-PM and NT-PM + NPK The concentrations of nitrate (NO3−–N) did not differ in soils amended with T-PM and NT-PM, indicating a reduction in nitrification and NH4+–N accumulation in soils amended with PM tablets. Key words: Poultry manure, tablets, carbon mineralization, nitrogen mineralization, organic fertilizer

scholarly journals Nitrogen Availability in Biochar-Amended Soils with Excessive Compost Application

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 444 ◽  
Author(s):  
Chen-Chi Tsai ◽  
Yu-Fang Chang
Keyword(s):  
N Mineralization ◽  
Nitrogen Availability ◽  
Agricultural Soils ◽  
Inorganic Nitrogen ◽  
Clay Content ◽  
N Availability ◽  
Net N Mineralization ◽  
Mineral N ◽  
Mineralization Potential ◽  
The Impact

Adding biochar to excessive compost amendments may affect compost mineralization rate and nitrogen (N) availability. The objective of this 371-day incubation study was to evaluate the effects of four proportions of woody biochar (0%, 0.5%, 1.0%, and 2.0%) from lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C through dynamic mineral N and N mineralization rates in three rural soils (one Oxisol and two Inceptisols). In each treatment, 5% poultry–livestock manure compost was added to serve as an excessive application. The results indicated that the biochar decreased available total inorganic nitrogen (TIN) (NO3−-N+NH4+-N) by on average 6%, 9% and 19% for 0.5%, 1.0% and 2.0% treatments, respectively. The soil type strongly influenced the impact of the biochar addition on the soil nitrogen mineralization potential, especially the soil pH and clay content. This study showed that the co-application of biochar and excessive compost benefited the agricultural soils by improving NO3−-N retention in agroecosystems. The application of biochar to these soils to combine it with excessive compost appeared to be an effective method of utilizing these soil amendments, as it diminished the net N mineralization potential and reduced the nitrate loss of the excessive added compost.

scholarly journals The effect of long-term CO2 enrichment on carbon and nitrogen content of roots and soil of natural pastureland

2021 ◽  
Vol 48 (2) ◽  
pp. 180-190
Author(s):  
Manal Al-Traboulsi ◽  
Brian Wilsey ◽  
Catherine Potvin
Keyword(s):  
N Mineralization ◽  
Co2 Enrichment ◽  
Net N Mineralization ◽  
Soil N ◽  
N Content ◽  
Total N ◽  
Soil C ◽  
Soil N Mineralization ◽  
C And N ◽  
The Impact

Abstract Increasing levels of atmospheric CO2 may change C and N dynamics in pasture ecosystems. The present study was conducted to examine the impact of four years of CO2 enrichment on soil and root composition and soil N transformation in natural pastureland. Plots of open-top growth chambers were continuously injected with ambient CO2 (350 µL L–1) and elevated CO2 (625 µL L–1). Soil cores exposed to ambient and elevated CO2 treatment were incubated and collected each year. Net N-mineralization rates in soil (NH4 +-N plus NO3ˉ–-N), in addition to total C and N content (%) of soil and root tissues were measured. Results revealed that elevated CO2 caused a significant reduction in soil NO3 (P < 0.05), however, no significant CO2 effect was found on total soil C and N content (%). Roots of plants grown under elevated CO2 treatment had higher C/N ratios. Changes in root C/N ratios were driven by changes in root N concentrations as total root N content (%) was significantly reduced by 30% (P < 0.05). Overall, findings suggest that the effects of CO2 enrichment was more noticeable on N content (%) than C content (%) of soil and roots; elevated CO2 significantly affected soil N-mineralization and total N content (%) in roots, however, no substantial change was found in C inputs in CO2-enriched soil.

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.

Nitrogen accumulations and relative rates of mineralization in two soils following legume green manuring

1994 ◽  
Vol 74 (1) ◽  
pp. 23-28 ◽  
Author(s):  
D. C. Jans-Hammermeister ◽  
W. B. McGill ◽  
T. L. Jensen
Keyword(s):  
N Mineralization ◽  
Clay Content ◽  
Soil Conditions ◽  
Net N Mineralization ◽  
Soil N ◽  
Soil Mineral ◽  
N Accumulation ◽  
Green Manuring ◽  
Controlled Environments ◽  
Cycling System

The distribution and dynamics of N following green manuring of full bloom field pea (Pisum sativum ’Sirius’) were investigated in the soil mineral, microbial and non-microbial organic (NMO N) fractions at two contrasting field sites in central Alberta; one on a Chernozemic (Dark Brown) soil near Provost and the other on a Luvisolic (Gray Luvisol) soil near Rimbey. Soils were sampled four times during a 1-yr period. The accumulations of N in the whole soil and in the soil mineral and microbial fractions were similar between sites. Net mineralization rates under controlled environments were strongly influenced by pre-incubation soil conditions. The short-term dynamics of N were distinguished best between the two soils by mineralization rates normalized to selected soil fractions rather than on the basis of N accumulation in these fractions. Net N mineralization rates expressed on the basis of soil N, microbial N or NMO N were greater in the Luvisolic soil indicating a more rapid internal N cycling system and greater activity of microbial biomass. These observations were consistent with the hypothesis that higher rates are associated with soils of lower clay content. Key words: Soil N dynamics, N mineralization rate, legume green manuring, Chernozemic, Luvisolic

scholarly journals Composition and Decomposition of Peanut Residues in Georgia

2004 ◽  
Vol 31 (1) ◽  
pp. 6-11 ◽  
Author(s):  
K. S. Balkcom ◽  
C. W. Wood ◽  
J. F. Adams ◽  
B. H. Wood
Keyword(s):  
N Mineralization ◽  
Sandy Loam ◽  
Soil Types ◽  
Net N Mineralization ◽  
Limited Information ◽  
Arachis Hypogaea L ◽  
C And N Mineralization ◽  
Subsequent Crop ◽  
C And N ◽  
Harvest Residue

Abstract Legumes typically mineralize rapidly and can contribute to nitrogen (N) requirements of succeeding crops, but limited information exists on the mineralizable N content of peanut (Arachis hypogaea L.) residue. The objective of this study was to determine net N mineralization from two types of peanut residue for two soil types. Aboveground peanut residue (cv. Georgia Green) was collected 1 d prior to digging (PRE) and immediately after peanut threshing (POST). Leaf and stem residues were mixed and analyzed for carbon (C), N, lignin, and cellulose. Peanut residue equivalent to 4.5 Mg/ha was applied to a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults) and a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudult) and aerobically incubated for 98 d in the dark at 25 C to determine C and N mineralization. Each soil was incubated simultaneously, with and without residue. PRE harvest residue had lower C, lignin, and cellulose concen-trations, but higher N concentrations than POST harvest residue. Differences in residue quality corresponded to differences in cumulative C mineralized and C turnover for the Tifton soil, but did not result in differences for cumulative N mineralized or relative N mineralized within either soil type. These data indicate that peanut residue will not supply significant amounts of N to a subsequent crop for these two soil types.

Effects of carbon and lime additions on mineralization of C and N in humus from cutovers of western red cedar–western hemlock forests on northern Vancouver Island

1994 ◽  
Vol 24 (12) ◽  
pp. 2432-2438 ◽  
Author(s):  
C.E. Prescott ◽  
M.A. McDonald
Keyword(s):  
N Mineralization ◽  
Potato Starch ◽  
Western Hemlock ◽  
N Availability ◽  
Net N Mineralization ◽  
Glucose Addition ◽  
Red Cedar ◽  
C And N Mineralization ◽  
C And N ◽  
Western Red Cedar

The potential for amendments of simple C compounds or lime to improve N availability in humus from cedar–hemlock cutovers was tested in laboratory incubations and a greenhouse bioassay. Rates of C and N mineralization in samples of humus and woody humus during aerobic incubations in the laboratory were not affected by additions of potato starch. Mineralization of C was stimulated and net N mineralization was reduced after glucose addition. Microorganisms in humus may not be capable of degrading starch, and simpler C sources such as glucose increase immobilization of N in microbial biomass. The biomass of seedlings of western red cedar (Thujaplicata Donn), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Sitka spruce (Piceasitchensis (Bong.) Carr.) grown in pots containing cedar–hemlock humus amended with dolomitic lime was similar to the biomass of seedlings grown in unamended humus after 18 months. Seedlings grown in humus amended with N and P fertilizers were significantly larger than those grown in unamended or lime-amended humus. It is unlikely that applications of C or lime to cedar–hemlock cutovers would increase rates of N mineralization from humus. Additions of nutrients appear to be the only practical means of alleviating the nutrient supply problems on these sites.

C and N mineralization of composted and anaerobically stored ruminant manure in differently textured soils

2000 ◽  
Vol 135 (2) ◽  
pp. 151-159 ◽  
Author(s):  
INGRID K. THOMSEN ◽  
JØRGEN E. OLESEN
Keyword(s):  
N Mineralization ◽  
Storage Period ◽  
Clay Content ◽  
Organic N ◽  
Net N Mineralization ◽  
Turnover Rates ◽  
Inorganic N ◽  
Available N ◽  
C Pools ◽  
Anaerobic Storage

Three animal manures cross-labelled with 15N in either the urine, faeces or straw fractions were prepared. After a storage period of 86 days when the manures were exposed to either composting or to anaerobic storage, portions of the manures were incubated in six differently textured soils with clay contents ranging from 11 to 45%. Evolved CO2-C was determined during a 266 day incubation and inorganic N and 15N in soil were measured at the termination of the incubation. The mineralization of C was analysed using first-order kinetics, and two C pools with fast (P1) and slow (P2) turnover rates were estimated. The total conversion of added C (Ps) was estimated as Ps=P1+P2.The cumulated CO2 production was considerably higher from soils incubated with anaerobically stored manure compared with soils amended with composted manure. CO2 production levelled off after c. 60 days in the three sandier soils whereas CO2 continued to be produced throughout the incubation from the three soils with the highest clay content. More C was assigned to the easily decomposable P1 pool in the sandiest soils whereas the more recalcitrant P2 pool was larger in the soils with higher clay content. Because of the different relationships between soil texture and C pools, Ps ended up being similar for five of the six soils. When taking C losses during the preceding storage into account, the accumulated C losses during storage and after incubation in soil accounted for 60 and 54% of C initially present in the composted and anaerobically stored manure, respectively.Net N mineralization which averaged 16% of applied organic N took place in all soils amended with composted manure. Soils with anaerobically stored manure showed net immobilization after the 266 days of incubation. The amount of N immobilized accounted for up to 30% of the inorganic N applied with the manure. As anaerobically stored manure generally loses less inorganic N during storage, it may contain more inorganic N than composted manure at the time of field application. Because of the immobilization that takes place after application of anaerobically stored manure to soil, the immediate levels of plant available N in soil may not be as different from soil supplied with composted manure as could be expected from the inorganic N content in the two types of manure. However, when considering the manure as a N resource, anaerobic storage is superior to composting.

Soil N and C transformations in two forest clear-cuts during three years after mounding and inverting

2007 ◽  
Vol 87 (3) ◽  
pp. 251-258 ◽  
Author(s):  
A. Smolander ◽  
J. Heiskanen
Keyword(s):  
Soil Solution ◽  
N Mineralization ◽  
Untreated Control ◽  
Site Preparation ◽  
Net N Mineralization ◽  
C Mineralization ◽  
Clear Cut ◽  
Net Nitrification ◽  
Humus Layer ◽  
C And N

Transformations of nitrogen and carbon in the humus layer were studied in central Finland on two clear-cut forest sites for 3 yr after spot mounding and inverting together with an untreated control. In laboratory-incubation experiments, samples from the humus layer were measured for rates of C mineralization, net N mineralization and net nitrification, and the amounts of C and N in the microbial biomass were determined. Soil solutions were collected for 4 yr with suction lysimeters. Overall, site preparation did not affect the rate of net N mineralization significantly (per kg organic matter). In the first growing season, however, the mean rate of net N mineralization was higher in both site preparation treatments than in the untreated control. At first, net nitrification was negligible in all treatments, but in the second year it increased in both site preparation treatments. On the other site, C mineralization was lowest with inverting, but the amounts of microbial C and N were highest. This indicates a shortage of easily mineralizable C sources in inverted spots. In the soil solution collected below the humus layer, increased concentrations of NO3-N and total N were found in both site-preparation treatments but, during the fourth year, overall concentrations of N had declined. Key words: Boreal forest, clear-cut, N transformations, site preparation, soil solution

Soil carbon and nitrogen pools and processes in an old-growth conifer forest 13 years after trenching

1998 ◽  
Vol 28 (8) ◽  
pp. 1261-1265 ◽  
Author(s):  
Stephen C Hart ◽  
Phil Sollins
Keyword(s):  
Water Content ◽  
N Mineralization ◽  
Microbial Biomass C ◽  
Net N Mineralization ◽  
Conifer Forest ◽  
Old Growth ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Soil C And N ◽  
C And N

We measured surface soil (0-15cm) C and N pools and processes inside and outside an area that had been trenched 13 years earlier in an old-growth conifer forest (>450 years) to assess the long-term impacts of reduced root inputs on C and N turnover. Trenching, combined with frequent clipping of understory plants, was originally conducted to prevent nutrient uptake by plants, as part of a study of the role of vegetation in ecosystem retention of N. Thirteen years following trenching, the median values of bulk density, pH, total C and N concentrations, annual rates of in situ net N mineralization and nitrification, microbial biomass C and N, microbial respiration, and anaerobically mineralizable N in the trenched plot were all within the 25-75% interquartile range of values found in the replicated, untrenched plots. The trenched plot had higher rates of net N mineralization (41% higher in October, 484% higher in June) and net nitrification (25% higher in October, and lower net NO3- immobilization in June) during laboratory incubation and a 22% higher water content in October. In June, soil water content in the trenched plot was about 8% lower than in the untrenched plots. Our results suggest that soil C and N dynamics in these old-growth forests are relatively resistant to perturbations resulting from major reductions in root input to the soil.

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