EFFECTS OF TEMPERATURE AND ROOT ON DENITRIFICATION IN A SOIL

1976 ◽  
Vol 56 (2) ◽  
pp. 79-87 ◽  
Author(s):  
L. D. BAILEY
Keyword(s):  
Relative Proportion ◽  
Gas Production ◽  
Soil Samples ◽  
No Production ◽  
Soil System ◽  
Ap Horizon ◽  
Effects Of Temperature ◽  
Nitrogenous Gases ◽  
Crop System

The effects of temperature on denitrification were studied in a soil system with a root in situ and one without a root. Soil samples of the Ap horizon of a Huron soil were used in the laboratory study. Germinated corn seedlings were planted and grown in cylinders for 84 h. At the end of this time the cylinders were cut horizontally so that the bottom 8.8-cm portion contained one root. Other cylinders were left unplanted. The soil in the cylinders was saturated with 5 ml of distilled water or 5 ml of a KNO3 solution. The rate of denitrification, both in terms of NO3− reduction and nitrogenous gas production, was more rapid in the system containing a root than in the fallowed system. Qualitatively, nitrogenous gases (N2, N2O and NO) were produced by both systems. At 30, 15 and 10 C there were no significant differences in the total quantity of gases produced by both systems. However, at all temperatures the crop system produced the larger quantities of NO, and also accumulated the larger quantities of NO2− and exchangeable NH4+. The root initially absorbed a portion of the added NO3−; however, with time the NO3− concentration of the root decreased to zero. The amount of NO3− taken up by the root and the rate at which the NO3− content of the root decreased was greatest at the high temperatures. At 5 C there was uptake of NO3− by the root but no decrease in the NO3− concentration of the root. Decreasing the temperature decreased the rate of denitrification, both in terms of NO3− reduction and nitrogenous gas production. At 5 C, denitrification was completely inhibited. Decreasing the temperature also changed the relative proportion of the nitrogenous gases produced. The quantity of N2 produced decreased as the temperature was decreased from 30 to 6–8 C. The decrease in temperature resulted in an increase in NO production; this was the principal gas produced at 6–8 C. Nitrous oxide (N2O) production, like NO, increased as the temperature decreased from 30 C to 10 C where it was the principal gas produced. At 30 to 15 C and 6–8 C, N2O production was secondary in quantity to N2 and NO, respectively.

EFFECTS OF TEMPERATURE ON NO3− AND NO2− REDUCTION, NITROGENOUS GAS PRODUCTION, AND REDOX POTENTIAL IN A SATURATED SOIL

1973 ◽  
Vol 53 (2) ◽  
pp. 213-218 ◽  
Author(s):  
L. D. BAILEY ◽  
E. G. BEAUCHAMP
Keyword(s):  
Redox Potential ◽  
Nitrogen Source ◽  
Low Temperatures ◽  
Slow Rate ◽  
Gas Production ◽  
Saturated Soil ◽  
Anaerobic Conditions ◽  
Ap Horizon ◽  
Effects Of Temperature ◽  
No2 Reduction

Samples of the Ap horizon of a Huron soil were used to investigate the effects of temperature on NO3− and NO2− reduction, nitrogenous gas production, and redox potential under anaerobic conditions in the laboratory. NO3− and NO2− reduction occurred at redox potential (Eh) values of 200 and 180 mV, respectively. The rate of NO3− and NO2− reduction decreased with decreasing temperatures (30–5 C). At 5 C, NO3− reduction was completely inhibited but NO2− reduction continued at a slow rate. Gas chromatographic analyses showed that the denitrification gas was composed of N2, N2O, and NO. Decreasing the temperature decreased the production of N2, increased the production of NO, and did not significantly affect the production of N2O. The increased production of NO at low temperatures when NO2− was the nitrogen source is attributed to chemodenitrification processes.

scholarly journals Evaluation of the Nutrient Composition, In Vitro Fermentation Characteristics, and In Situ Degradability of Amaranthus caudatus, Amaranthus cruentus, and Amaranthus hypochondriacus in Cattle

Animals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 18
Author(s):  
Kim Margarette C. Nogoy ◽  
Jia Yu ◽  
Young Gyu Song ◽  
Shida Li ◽  
Jong-Wook Chung ◽  
...  
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Gas Production ◽  
Nutrient Composition ◽  
Neutral Detergent Fiber ◽  
Amaranthus Cruentus ◽  
Amaranthus Caudatus ◽  
Amaranthus Hypochondriacus

The amaranth plants showed high potential feed value as forage for ruminants. An in-depth study of this plant, particularly in cattle, will help extend its utilization as an alternative protein and fiber feed source in cattle feeding. In this study, the nutrient compositions of three different species of amaranth, Amaranthus caudatus L., Amaranthus cruentus L., and Amaranthus hypochondriacus L.—two varieties for each species, A.ca 74, A.ca 91, A.cu 62, A.cu 66, A. hy 30, and A. hy 48—were evaluated. The in vitro technique was used to evaluate the fermentation characteristics such as total gas production, total volatile fatty acids (VFA) concentration, pH, and ammonia concentration of the rumen fluid. Moreover, the effective degradabilities of dry matter (EDDM) and crude protein (EDCP) of the amaranth forages were determined through in situ bag technique. The amaranth forages: A. caudatus, A. cruentus, and A. hypochondriacus showed better nutritive value than the locally produced forages in Chungcheong province of Korea. The CP of the amaranth ranged from 11.95% to 14.19%, and the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents ranged from 45.53% to 70.88% and 34.17% to 49.83%, respectively. Among the amaranth varieties, A. hypochondriacus 48 showed the most excellent ruminant feed nutrient quality (CP, 14.19%; NDF, 45.53%; and ADF, 34.17%). The effective degradabilities of dry matter (EDDM; 33–56%) and crude protein EDCP (27–59%) of the amaranth were lower compared to other studies, which could be due to the maturity stage at which the forages were harvested. Nonetheless, A. hypochondriacus 48 showed the highest EDDM (56.73%) and EDCP (59.09%). The different amaranth species did not differ greatly in terms of total VFA concentration or molar proportions, total gas production, or ammonia-N concentration. The high nutrient composition, and highly effective degradability of dry matter and crude protein, coupled with the favorable fermentation characteristics, suggest that the amaranth forages showed good to excellent feed quality for cattle.

In-situ quantification of NO synthesis in a warm air glow discharge by WMS-based Mid-IR QCL absorption spectroscopy

2022 ◽  
Author(s):  
Chuanqi Wang ◽  
Junjie Qiao ◽  
Yijia Song ◽  
Qi Yang ◽  
Dazhi Wang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Glow Discharge ◽  
Absorption Spectroscopy ◽  
Energy Cost ◽  
High Energy ◽  
Cathode Region ◽  
Synthesis Rate ◽  
No Production ◽  
Airflow Rate

Abstract Nitric oxide (NO) is one of the most crucial products in the plasma-based nitrogen fixation process. In this work, in-situ measurements were performed for quantifying the NO synthesis spatially in a warm air glow discharge, through the method of Mid-infrared quantum cascade laser absorption spectroscopy (QCL-AS). Two ro-vibrational transitions at 1900.076 cm-1 and 1900.517 cm-1 of the ground-state NO(X) were probed sensitively by the help of the wavelength modulation spectroscopy (WMS) approach to increase the signal/noise (S/N) level. The results show a decline trend of NO synthesis rate along the discharge channel from the cathode to the anode. However, from the point of energy efficiency, the cathode region is of significantly low energy efficiency of NO production. Severe disproportionality was found for the high energy consumption but low NO production in the region of cathode area, compared to that in the positive column zone. Further analysis demonstrates the high energy cost of NO production in the cathode region, is ascribed to the extremely high reduced electric field E/N therein not selectively preferable for the processes of vibrational excitation or dissociation of N2 and O2 molecules. This drags down the overall energy efficiency of NO synthesis by this typical warm air glow discharge, particularly for the ones with short electrode gaps. Limitations of further improving the energy cost of NO synthesis by variations of the discharge operation conditions, such as discharge current or airflow rate, imply other effective manners able to tune the energy delivery selectively to the NO formation process, are sorely needed.

Relationship between the gas production profiles of mixtures of hay and maize and the patterns of rumen fermentation observed in sheep fed those mixtures

1998 ◽  
Vol 1998 ◽  
pp. 63-63
Author(s):  
C. Rymer ◽  
D.I. Givens
Keyword(s):  
Growth Rate ◽  
Feed Intake ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Post Feeding ◽  
Molar Proportion ◽  
Rumen Ph ◽  
The Mean

The gas production (GP) technique has been developed to assess dynamics of ruminant digestion. Relationships have been observed between a feed's GP profile and in vivo parameters such as digestibility (Khazaal et al., 1993), feed intake and growth rate (Blümmel and Ørskov, 1993), and in situ degradability (Sileshi et al., 1997). However, there are few studies which relate GP data to the in vivo pattern of rumen fermentation (in terms of the rate of pH decline 2 h post-feeding and the mean rumen pH, concentration of total VFA and molar proportion of individual VFA). The object of this experiment was to determine whether such a relationship existed between a feed's GP profile and the pattern of rumen fermentation observed in animals fed that feed.

scholarly journals In situ immobilisation of heavy metals in soils using natural clay minerals

2020 ◽  
Vol 66 (No. 12) ◽  
pp. 632-638
Author(s):  
Senad Murtić ◽  
Emina Sijahović ◽  
Hamdija Čivić ◽  
Mirza Tvica ◽  
Josip Jurković
Keyword(s):  
Heavy Metals ◽  
Ethylenediaminetetraacetic Acid ◽  
Atomic Absorption Spectrophotometry ◽  
Soil Samples ◽  
Natural Clay ◽  
Aqua Regia ◽  
Absorption Spectrophotometry ◽  
Suitable Technique ◽  
Heavy Metals In Soils

This study attempted to evaluate the efficiency of zeolite and pyrophyllite ore materials in reducing the mobility of heavy metals in soil near the lignite mining dumps, and consequently in their availability for plants. Extraction of pseudo-total and available forms of heavy metals from soil samples was performed by using aqua regia and ethylenediaminetetraacetic acid, respectively. Concentrations of heavy metals in soil and plant samples were determined by atomic absorption spectrophotometry. The results of this study illustrate that application of zeolite and pyrophyllite could be a suitable technique to reduce heavy metals availability in soils. Zeolite treatments have been shown to be significantly effective in reducing cadmium (Cd) mobility, as well as pyrophyllite treatments in reducing lead (Pb) mobility in the studied soil, regardless of applied rates. The accumulation of heavy metals in leaves of maize grown on soil plots treated by zeolite and pyrophyllite, was found to be lower compared to the untreated plots. This finding was to be expected, considering the effects of these treatments on heavy metals mobility in the studied soil.

Is it possible to determine formation processes of organic deposits through polysaccharides? Pilot study from the prehistoric site in Brandýs nad Labem, Czech Republic

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1273-1280
Author(s):  
Klement Rejšek ◽  
Jan Turek ◽  
Valerie Vranová ◽  
Roman Hadacz ◽  
Lenka Lisá
Keyword(s):  
Czech Republic ◽  
Pilot Study ◽  
Organic Material ◽  
Archaeological Site ◽  
Soil Samples ◽  
Formation Processes ◽  
Cultural Layer ◽  
Different Types ◽  
Organic Deposits

This paper deals with a possible interpretation value of biochemical methods in comparison with the classic tools of geoarchaeology for the evaluation of formation processes. Organic rich layers from the archaeological site Brandýs nad Labem-Vrábí were tested with the aim to determine the origin of several different types of soil organic material by analyzing the content of different sugars. The studied soil body showed signs of cultural layer, redeposited soils, and in situ developed soil. The analysis of different sugars was highlighted: soil samples taken from these layers were analyzed to assess the ratios of mannose + galactose to arabinose + xylose, and of rhamnose + fucose to arabinose + xylose, content of Corg and different nitrates, as well as different rates of absorbance. The results show that the interpretation values of polysaccharides evaluation didn’t bring significant results itself, but in combination with classical tools of geoarchaeology may bring interpretable and new results.

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