EFFECT OF WHEAT STRAW INCORPORATION ON DENITRIFICATION OF N UNDER ANAEROBIC AND AEROBIC CONDITIONS

1987 ◽  
Vol 67 (4) ◽  
pp. 825-834 ◽  
Author(s):  
M. S. AULAKH ◽  
D. A. RENNIE
Keyword(s):  
Wheat Straw ◽  
Water Saturation ◽  
Initial Period ◽  
Fertilizer N ◽  
N Losses ◽  
Total Period ◽  
Organic C ◽  
Key Words Denitrification ◽  
Straw Incorporation ◽  
Water Saturated

The effects of wheat straw incorporation on denitrification, immobilization of N, and C mineralization were investigated at H2O contents of 60, 90 and 120% saturation. Incorporation of increasing levels of straw consistently increased the rate of denitrification for the first 4–8 d, followed by negligible N losses thereafter. In a total period of 96 d, the addition of 1.0% straw increased N losses from 2.5 to 10.1, and from 61.6 to 83.9 μg g−1 in the 60 and 120% water saturation treatments, respectively. The pattern of CO2-C evolved was practically identical to that of the denitrification rate for the initial period when sufficient [Formula: see text] was present. This study has confirmed that in flooded soils, high rates of denitrification will persist only when C is supplied by native or applied organic C sources, provided adequate [Formula: see text] is present. When [Formula: see text] was low, denitrification rates rapidly decreased, even with a sufficient supply of C. Immobilization of fertilizer N (50 μg N g−1 as K15NO3) was very rapid. Around 90% of the total immobilization of applied N occurred within 4 d. Incorporation of 1.0% straw increased the immobilization of fertilizer N from 8.4 to 42.8, and from 1.0 to 7.6% in the 60 and 120% water-saturated treatments, respectively. Remineralization of recently immobilized fertilizer N was observed after 32 d in the 60% saturation treatments only. Key words: Denitrification, wheat straw, mineralization of N

scholarly journals Wheat Straw Incorporation Affecting Soil Carbon and Nitrogen Fractions in Chinese Paddy Soil

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 803
Author(s):  
Wei Dai ◽  
Jun Wang ◽  
Kaikai Fang ◽  
Luqi Cao ◽  
Zhimin Sha ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Wheat Straw ◽  
Paddy Soil ◽  
Rice Paddy ◽  
Water Soluble ◽  
Microbial Biomass N ◽  
Rice Grain ◽  
Organic C ◽  
Straw Incorporation ◽  
N Fractions

Soil organic carbon (SOC) and nitrogen (N) fractions greatly affect soil health and quality. This study explored the effects of wheat straw incorporation on Chinese rice paddy fields with four treatments: (1) a control (CK), (2) a mineral NPK fertilizer (NPK), (3) the moderate wheat straw (3 t ha−1) plus NPK (MSNPK), and (4) the high wheat straw (6 t ha−1) plus NPK (HSNPK). In total, 0–5, 5–10, 10–20, and 20–30 cm soil depths were sampled from paddy soil in China. Compared with the CK, the HSNPK treatment (p < 0.05) increased the C fraction content (from 13.91 to 53.78%), mainly including SOC, microbial biomass C (MBC), water-soluble organic C (WSOC), and labile organic C (LOC) in the soil profile (0–30 cm), and it also (p < 0.05) increased the soil N fraction content (from 10.70 to 55.31%) such as the soil total N (TN) at 0–10 cm depth, microbial biomass N (MBN) at 0–20 cm depth, total water-soluble N (WSTN) at 0–5 and 20–30 cm depths, and total labile N (LTN) at 0–30 cm depth. The primary components of soil LOC and LTN are MBC and MBN. Various soil C and N fractions positively correlated with each other (p < 0.05). The HSNPK treatment promoted the soil MBC, WSOC, and LOC to SOC ratios, and also promoted MBN, WSTN, and LTN to soil TN ratios at a depth of 0–20 cm. To summarize, the application of HSNPK could maintain and improve rice paddy soil quality, which leads to increased rice grain yields.

OVERWINTER LOSSES OF NITROGEN-15 LABELLED UREA FERTILIZER

1986 ◽  
Vol 66 (3) ◽  
pp. 513-520 ◽  
Author(s):  
J. B. BOLE ◽  
W. D. GOULD
Keyword(s):  
Field Studies ◽  
Early Spring ◽  
Nitrification Inhibitors ◽  
Fertilizer N ◽  
N Losses ◽  
Key Words Denitrification ◽  
Support Practices ◽  
Residual Fertilizer N ◽  
Fall Application ◽  
Irrigated Soils

Field studies using 15N microplots were conducted to quantify the uptake and disappearance of fall- and spring-applied urea N on low organic matter, irrigated soils. Urea was mixed with the surface soil to maximize the potential for overwinter nitrification and subsequent losses of the fertilizer N. In three irrigated soils, losses of fall-applied urea averaged 24–31% compared with 11–21% of that applied at seeding. Barley took up 33–42% of spring-applied urea N but only 16–36% of fall-applied urea N. The lower uptake of fall-applied N apparently resulted from higher N losses rather than from the immobilization of fall-applied urea. Fall application resulted in lower soil reserves of residual fertilizer N after the growing season, as compared to spring application, in two of the three studies. Sixty percent of the fertilizer N recovered from the soil remained in the surface 15 cm. The application of 50 mm of water in the fall or 100 mm in the early spring, to intensify any effects of moisture, had a minimal effect on N losses or the distribution of N in the soil. This suggests that an individual rainfall event would not greatly affect the uptake or losses of fall-applied fertilizer on well-drained soil. The observed fertilizer losses, however, support practices such as concentrating fall-applied fertilizers in bands or the use of nitrification inhibitors. Key words: Denitrification, nitrogen, fertilizer, N balance, N losses, urea

Denitrification and nitrous oxide emissions from a Black Chernozemic soil during spring thaw in Alberta

1997 ◽  
Vol 77 (2) ◽  
pp. 153-160 ◽  
Author(s):  
M. Nyborg ◽  
J. W. Laidlaw ◽  
E. D. Solberg ◽  
S. S. Malhi
Keyword(s):  
Nitrous Oxide ◽  
Mass Balance ◽  
Water Saturation ◽  
Field Research ◽  
Frozen Soil ◽  
Nitrous Oxide Emissions ◽  
Produce Water ◽  
Balance Technique ◽  
Key Words Denitrification ◽  
Water Saturated

Previous field research in Alberta has suggested that denitrification occurs mostly when soil thaws in the spring, with associated soil water saturation. Our objective was to determine if denitrification and N2O emission in fact take place in cold, thawing soil in the field. Denitrification and N2O flux were measured in two springs and the intervening summer. Cylinders were placed in soil in November, 1988, and 57 kg N ha−1 of 15Nlabeled KNO3 was added. Soil 15N mass balance technique showed 23 kg N ha−1 of added-N was lost by 15 May 1989. Gas trappings were made (28 March to 29 April) and nearly all of the N2O emission (3.5 kg N2O-N ha−1) occurred during an 11-d period of thaw. The accumulated N2O flux from 20 June to 31 August was small (0.5 kg N2O-N ha−1, or less); during that time there were no rainfall events intense enough to produce water saturated soil. In 1990, 15N-labeled KNO3 (100 kg N ha−1) was applied on 26 March (outset of the thaw) and mass balance showed 32.7 kg N ha−1of added-N was lost by 7 May. A flux of 16.3 kg N2O-N ha−1 occurred largely in a 10-d period during and immediately after soil thaw. The N2O emitted from soil left a considerable fraction of the lost N unaccounted for. This unaccounted N was most likely lost as gaseous N other than N2O (e.g., N2). We conclude that large amounts of soil nitrate may be denitrified, with smaller amounts emitted as N2O, as the soil thaws and soon thereafter. Key words: Denitrification, frozen soil, thawing soil, nitrogen, nitrous oxide

EFFECT OF WHEAT, LEGUME AND LEGUME-ENRICHED WHEAT RESIDUES ON THE PRODUCTIVITY AND NITROGEN UPTAKE OF RICE-WHEAT CROPPING SYSTEM AND SOIL FERTILITY

2001 ◽  
Vol 49 (4) ◽  
pp. 369-378 ◽  
Author(s):  
S. N. SHARMA ◽  
R. PRASAD
Keyword(s):  
Adverse Effect ◽  
Soil Fertility ◽  
Nitrogen Uptake ◽  
Green Manure ◽  
N Uptake ◽  
Cropping System ◽  
Available P ◽  
Fertilizer N ◽  
Organic C ◽  
Green Manuring

Field experiments were conducted for two crop years at the Indian Agricultural Research Institute, New Delhi to study the effect of enriching wheat residue with legume residue on the productivity and nitrogen uptake of a rice-wheat cropping system and soil fertility. The incorporation of wheat residue had an adverse effect on the productivity of the rice-wheat cropping system. When it was incorporated along with Sesbania green manure, not only did its adverse effect disappear but the response to fertilizer N was also increased. There was no response to fertilizer N when Sesbania green manure was incorporated. When wheat residue was incorporated along with Sesbania green manuring, rice responded significantly to fertilizer N up to 120 kg N ha-1 in the first year and to 60 kgN ha-1 in the second year and at these levels of N, Sesbania + wheat residue gave 0.8 to 1.2 t ha-1 more grain, 0.6-1.0 t ha-1 more straw and 8-15 kg ha-1 more N uptake of rice resulting in 0.04-0.17% more organic C, 3-8 kg ha-1 more available P and 17-25 kg ha-1 more available K content in the soil than wheat residue alone at the same rates of N application. The respective increaseas caused by Sesbania green manure + wheat residue over Sesbania green manure alone were 0.3-0.5 t ha-1 in the grain and straw yield, 1-9 kg ha-1 in the N uptake of rice, 0.02-0.10% in organic C, 1-8 kg ha-1 in available P and 35- 70 kg ha-1 in available K content in the soil. These treatments also gave higher residual effects in succeeding wheat than wheat residue alone. The incorporation of residues of both wheat and Sesbania is thus recommended to eliminate the adverse effect of wheat residue and to increase the beneficial effects of Sesbania green manuring.

scholarly journals Implication of O2 dynamics for both N2O and CH4 emissions from soil during biological soil disinfestation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chen Wang ◽  
Xuehong Ma ◽  
Gang Wang ◽  
Guitong Li ◽  
Kun Zhu
Keyword(s):  
Wheat Straw ◽  
Crop Residues ◽  
Management Practice ◽  
Organic Amendments ◽  
Soil Disinfestation ◽  
Hypoxic Area ◽  
Hypoxic Fraction ◽  
Biological Soil Disinfestation ◽  
Straw Incorporation

AbstractSoil O2 dynamics have significant influences on greenhouse gas emissions during soil management practice. In this study, we deployed O2-specific planar optodes to visualize spatiotemporal distribution of O2 in soils treated with biological soil disinfestation (BSD). This study aimed to reveal the role of anoxia development on emissions of N2O and CH4 from soil amended with crop residues during BSD period. The incorporation of crop residues includes wheat straw only, wheat straw with biochar and early straw incorporation. The anoxia in soil developed very fast within 3 days, while the O2 in headspace decreased much slower and it became anaerobic after 5 days, which was significantly affected by straw and biochar additions. The N2O emissions were positively correlated with soil hypoxic fraction. The CH4 emissions were not significant until the anoxia dominated in both soil and headspace. The co-application of biochar with straw delayed the anoxia development and extended the hypoxic area in soil, resulting in lower emissions of N2O and CH4. Those results highlight that the soil O2 dynamic was the key variable triggering the N2O and CH4 productions. Therefore, detailed information of soil O2 availability could be highly beneficial for optimizing the strategies of organic amendments incorporation in the BSD technique.

Factors controlling N mineralization, nitrification, and nitrogen losses in an Oxisol amended with sewage sludge

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 519 ◽  
Author(s):  
J. Sierra ◽  
S. Fontaine ◽  
L. Desfontaines
Keyword(s):  
Sewage Sludge ◽  
Field Experiment ◽  
Water Content ◽  
N Mineralization ◽  
Initial Period ◽  
Factorial Experiment ◽  
Net N Mineralization ◽  
N Losses ◽  
Mineral N ◽  
The Difference

Laboratory incubations and a field experiment were carried out to determine the factors controlling N mineralization and nitrification, and to estimate the N losses (leaching and volatilization) in a sewage-sludge-amended Oxisol. Aerobically digested sludge was applied at a rate equivalent to 625 kg N/ha. The incubations were conducted as a factorial experiment of temperature (20˚C, 30˚C, and 40˚C) soil water (–30 kPa and –1500 kPa) sludge type [fresh (FS) water content 6230 g/kg; dry (DS) water content 50 g/kg]. The amount of nitrifiers was determined at the beginning and at the end of the experiment. The incubation lasted 24 weeks. The field study was conducted using bare microplots (4 m) and consisted of a factorial experiment of sludge type (FS and DS) sludge placement (subsurface, I+; surface, I–). Ammonia volatilization and the profile (0–0.90 m) of mineral N concentration were measured during 6 and 29 weeks after sludge application, respectively. After 24 weeks of incubation at 40˚C and –30 kPa, net N mineralization represented 52% (FS) and 71% (DS) of the applied N. The difference between sludges was due to an initial period of N immobilization in FS. Nitrification was more sensitive than N mineralization to changes in water potential and it was fully inhibited at –1500 kPa. The introduction of a large amount of nitrifiers with FS did not modify the rate of nitrification, which was principally limited by soil acidity (pH 4.9). Although N mineralization was greatest at 30˚C, nitrification increased continuously with temperature. Nitrogen mineralization from DS was well described by the double-exponential equation. For FS, the equation was modified to take into account an immobilization-remineralization period. Sludge placement significantly affected the soil NO-3/NH+4 ratio in the field: 16 for I+ and 1.5 for I–, after 11 weeks. In the I– treatment, nitrification of the released NH+4 was limited by soil moisture because of the dry soil mulch formed a few hours after rain. At the end of the field experiment, the estimated losses of N by leaching were 432 kg N/ha for I+ and 356 kg N/ha for I–. Volatilization was not detectable in the I+ microplots and it represented only 0.5% of the applied N in the I– microplots. The results showed that placement of sludge may be a valuable tool to decrease NO-3 leaching by placing the sludge under unfavourable conditions for nitrification.

scholarly journals Extent and Variation of Nitrogen Losses from Non-legume Field Crops of Conterminous United States

Nitrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 34-51
Author(s):  
Amitava Chatterjee
Keyword(s):  
United States ◽  
Management Strategies ◽  
Application Rate ◽  
Fertilizer N ◽  
N Loss ◽  
N Losses ◽  
Field Crops ◽  
N Application Rate ◽  
Spatio Temporal ◽  
N Management

Nitrogen (N) losses from field crops have raised environmental concerns. This manuscript accompanies a database of N loss studies from non-legume field crops conducted across the conterminous United States. Cumulative N losses through nitrous oxide-denitrification (CN2O), ammonia volatilization (CNH3), and nitrate leaching (CNO3−) during the growing season and associated crop, soil, and water management information were gathered to determine the extent and controls of these losses. This database consisted of 404, 26, and 358 observations of CN2O, CNH3, and CNO3− losses, respectively, from sixty-two peer-reviewed manuscripts. Corn (Zea mays) dominated the N loss studies. Losses ranged between −0.04 to 16.9, 2.50 to 50.9, and 0 to 257 kg N ha−1 for CN2O, CNH3 and CNO3−, respectively. Most CN2O and CNO3− observations were reported from Colorado (n = 100) and Iowa (n = 176), respectively. The highest values of CN2O, and CNO3− were reported from Illinois and Minnesota states, and corn and potato (Solanum tuberosum), respectively. The application of anhydrous NH3 had the highest value of CN2O loss, and ammonium nitrate had the highest CNO3− loss. Among the different placement methods, the injection of fertilizer-N had the highest CN2O loss, whereas the banding of fertilizer-N had the highest CNO3− loss. The maximum CNO3− loss was higher for chisel than no-tillage practice. Both CN2O and CNO3− were positively correlated with fertilizer N application rate and the amount of water input (irrigation and rainfall). Fertilizer-N management strategies to control N loss should consider the spatio-temporal variability of interactions among climate, crop-and soil types.

Petrophysical Type Curves for Identifying the Electrical Character of Petroleum Reservoirs

2007 ◽  
Vol 10 (06) ◽  
pp. 711-729 ◽  
Author(s):  
Paul Francis Worthington
Keyword(s):  
Water Saturation ◽  
Early Stage ◽  
Well Logs ◽  
Log Analysis ◽  
Well Log ◽  
Formation Water ◽  
Water Conductivity ◽  
Core Data ◽  
Water Saturated ◽  
Petrophysical Evaluation

Summary A user-friendly type chart has been constructed as an aid to the evaluation of water saturation from well logs. It provides a basis for the inter-reservoir comparison of electrical character in terms of adherence to, or departures from, Archie conditions in the presence of significant shaliness and/or low formation-water salinity. Therefore, it constitutes an analog facility. The deliverables include reservoir classification to guide well-log analysis, a protocol for optimizing the acquisition of special core data in support of log analysis, and reservoir characterization in terms of an (analog) porosity exponent and saturation exponent. The type chart describes a continuum of electrical behavior for both water and hydrocarbon zones. This is important because some reservoir rocks can conform to Archie conditions in the fully water-saturated state, but show pronounced departures from Archie conditions in the partially water-saturated state. In this respect, the chart is an extension of earlier approaches that were restricted to the water zone. This extension is achieved by adopting a generalized geometric factor—the ratio of water conductivity to formation conductivity—regardless of the degree of hydrocarbon saturation. The type chart relates a normalized form of this geometric factor to formation-water conductivity, a "shale" conductivity term, and (irreducible) water saturation. The chart has been validated using core data from comprehensively studied reservoirs. A workflow details the application of the type chart to core and/or log data. The analog role of the chart is illustrated for reservoir units that show different levels of non-Archie effects. The application of the method should take rock types, scale effects, the degree of core sampling, and net reservoir criteria into account. The principal benefit is a reduced uncertainty in the choice of a procedure for the petrophysical evaluation of water saturation, especially at an early stage in the appraisal/development process, when adequate characterizing data may not be available. Introduction One of the ever-present problems in petrophysics is how to carry out a meaningful evaluation of well logs in situations where characterizing information from quality-assured core analysis is either unavailable or is insufficient to satisfactorily support the log interpretation. This problem is especially pertinent at an early stage in the life of a field, when reservoir data are relatively sparse. Data shortfalls could be mitigated if there was a means of identifying petrophysical analogs of reservoir character, so that the broader experience of the hydrocarbon industry could be utilized in constructing reservoir models and thence be brought to bear on current appraisal and development decisions. Here, a principal requirement calls for type charts of petrophysical character, on which data from different reservoirs can be plotted and compared, as a basis for aligning approaches to future data acquisition and interpretation. This need manifests itself strongly in the petrophysical evaluation of water saturation, a process that traditionally uses the electrical properties of a reservoir rock to deliver key building blocks for an integrated reservoir model. The solution to this problem calls for an analog facility through which the electrical character of a subject reservoir can be compared with others that have been more comprehensively studied. In this way, the degree of confidence in log-derived water saturation might be reinforced. At the limit, the log analyst needs a reference basis for recourse to capillary pressure data in cases where the well-log evaluation of water saturation turns out to be prohibitively uncertain.

scholarly journals Settlement and bearing capacity of water-saturated soils of foundations of finite width under static impact

Vestnik MGSU ◽  
2021 ◽  
pp. 463-472
Author(s):  
Zaven G. Ter-Martirosyan ◽  
Armen Z. Ter-Martirosyan ◽  
Ahmad Othman
Keyword(s):  
Bearing Capacity ◽  
Strain State ◽  
Water Saturation ◽  
Strength Properties ◽  
Finite Width ◽  
Stress Strain ◽  
Linear Deformation ◽  
Stress Strain State ◽  
Linear And Nonlinear ◽  
Water Saturated

Introduction. In case of brief exposure to static loads or dynamic loads, in conditions of absence of drainage, distribution of total stresses between the skeleton of soil and pore gas-containing water should be taken in account. The situation of the stress-strain state of the base is further complicated when we consider the degree of water-saturation of soil of the foundation (0.8 < Sr ≤ 1). The aim of the study is to pose and solve problem of the stress-strain state of a water-saturated soil massif, Including settlement and bearing capacity of a water-saturated base of a foundation of finite width, depending on the degree of water saturation of soils, taking into account the linear and nonlinear properties of the skeleton of soil and the compressibility of pore gas-containing water. Materials and methods. Henckyʼs system of physical equations are used as a calculation model to describe the relationship between deformation and stresses of soil, which takes into account the influence of the average stress on the deformation and strength properties of the soil. This system allows us to represent the linear deformation of the soil as the sum of the volumetric and shear components of the soil of this deformation. In addition allows us too to determine the deformation of the layer of soil, as part of the compressible thickness of the base of foundation with finite width under conditions of free deformations. Results. Depending on the linear and nonlinear deformation parameters, the settlement can be developed with a damped curve (S – p) and stabilize, and can be developed with a non-damped curve (S – p) and moved to the stage of progressive settlement. Conclusions. Solutions have been made for cases when the water-saturation of the base soils changes in the range of 0.8 to 1.0. It is shown that the settlement and bearing capacity of a water-saturated base significantly depends on the degree of water saturation of soils.

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