Effect of organic matter and urease inhibitors on urea hydrolysis and immobilization of urea nitrogen in an alkaline soil

1991 ◽  
Vol 11 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Wang Zhengping ◽  
O. Van Cleemput ◽  
Li Liantie ◽  
L. Baert
Keyword(s):  
Organic Matter ◽  
Urea Hydrolysis ◽  
Urease Inhibitors ◽  
Alkaline Soil ◽  
Urea Nitrogen

EFFECTS OF CATECHOL AND P-BENZOQUINONE ON THE HYDROLYSIS OF UREA AND ENERGY BARRIERS OF UREASE ACTIVITY IN SOILS

1984 ◽  
Vol 64 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J. S. TOMAR ◽  
A. F. MacKENZIE
Keyword(s):  
Activation Energy ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Key Words ◽  
Urease Activity ◽  
Urea Hydrolysis ◽  
Urease Inhibitors ◽  
Soil Urease ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

The effects of the urease inhibitors, catechol and p-benzoquinone, and temperature on the hydrolysis of urea in five soils were investigated in a laboratory study. Urea hydrolysis decreased significantly with the amount of inhibitors applied and increased significantly with each 5 °C increase in temperature from 5 to 25 °C. The effectiveness of inhibitors generally decreased with increases in temperature from 5 to 25 °C. The correlation of hydrolysis of urea with organic matter contents of the soils was highly significant (r = 0.67** to 0.86**). Both catechol and p-benzoquinone tended to increase the energies and entropies of activation of soil urease and the effect was enhanced with a decrease in soil organic matter. It is suggested that an increase in the activation energy of the soil urease as a result of inhibitor use was related to an increase in the effectiveness of the inhibitor. Key words: Urease inhibitors, urea hydrolysis, energy of activation

Metabolism of 15N-Labelled Urea in the Functioning and Defunctioned Human Colon

1990 ◽  
Vol 79 (3) ◽  
pp. 253-258 ◽  
Author(s):  
B. J. Moran ◽  
A. A. Jackson
Keyword(s):  
Human Colon ◽  
Urea Hydrolysis ◽  
Bacterial Activity ◽  
The Body ◽  
Urea Molecule ◽  
Urea Nitrogen ◽  
Nitrogen Pool ◽  
End Colostomy ◽  
15N Urea ◽  
The Right

1. The luminal metabolism of urea was studied using double-labelled urea ([15N2]urea) which was placed in the lumen of the colon through a colostomy. The recovery of label was measured as [15N2]urea or [14N,15N]urea in urine and as 15N in stool. 2. Five patients with a loop colostomy allowed a comparison of the right functioning colon with the left defunctioned colon in the same individual. Five subjects with a left end-colostomy enabled a comparison of the right with the left functioning colon. 3. A significantly greater proportion of labelled urea was recovered as [15N2]urea in the urine when the dose was placed in the left defunctioned colon (29%) compared with either the left or the right functioning colon (9 and 4%, respectively). This is interpreted as being a result of a decrease in the bacterial activity and concomitant urea hydrolysis in the defunctioned colon. 4. On average more than half of the label was retained in the body, regardless of whether the urea was placed in the functioning or the defunctioned colon, on the left or on the right. 5. The data confirm that the colon is permeable to the intact urea molecule. Intraluminal urea is readily hydrolysed in the functioning colon. A large proportion of the nitrogen released by urea hydrolysis may be retained within the metabolic nitrogen pool of the host. There are significant differences in the handling of urea nitrogen in the defunctioned colon relative to the functioning colon.

Sulfur forms in bulk soils and alkaline soil extracts of tropical mountain ecosystems in northern Thailand

Soil Research ◽  
2002 ◽  
Vol 40 (1) ◽  
pp. 161 ◽  
Author(s):  
A. Möller ◽  
K. Kaiser ◽  
N. Kanchanakool ◽  
C. Anecksamphant ◽  
W. Jirasuktaveekul ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Tropical Soils ◽  
Forest Site ◽  
Alkaline Soil ◽  
Northern Thailand ◽  
Total N ◽  
Soil Extracts ◽  
Organic C ◽  
Organic S

Sulfur, besides phosphorus, is crucial for the nutrition of plants on tropical soils. Its availability is closely related to the turnover of soil organic matter. To get a better insight into transformation of soil S forms during the decomposition of organic matter, we studied inorganic and organic S pools in bulk samples and alkaline extracts of soils under different land uses representative of the tropical highlands of northern Thailand. Samples were taken from a cabbage cultivation, a Pinus reforestation, a secondary forest, and a primary forest. Total S ranged from 483 549 mg/kg in the subsoil to 1909 376 mg/kg in the organic layers, which is relatively high for tropical soils. The major S component in soil was organic S, comprising 75–99% of total S. Organic S was significantly correlated with total S, organic C, and total N, indicating that there is a close relationship between C, N, and S cycling in soil. C-bonded S was the predominant form in the topsoils (35–99% of total S) but its presence decreased with soil depth. The maximum concentrations of ester SO4-S were found in the A horizons (128 49 mg/kg), whereas the concentrations of inorganic SO4-S were small in all horizons. Compared with the forest site, the cabbage cultivation site was strongly depleted in S. C-bonded S was more depleted than ester SO4-S. A comparison of the S forms in NaOH extracts with S forms in bulk soil and C forms as indicated by 13C-NMR spectroscopy showed (i) that the extracts were very representative of soil organic S fractions and (ii) that ester SO4-S was mainly associated with O-substituted aliphatic C. In contrast, C-bonded S seemed to be connected to more-or-less all C binding types. transformation of soil organic matter, sulfate.

scholarly journals Soil pH and Organic Matter Content Affects European Ash (Fraxinus excelsior L.) Crown Defoliation and Its Impact on Understory Vegetation

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 22 ◽  
Author(s):  
Krzysztof Turczański ◽  
Paweł Rutkowski ◽  
Marcin K. Dyderski ◽  
Dorota Wrońska-Pilarek ◽  
Mirosław Nowiński
Keyword(s):  
Organic Matter ◽  
Soil Ph ◽  
Organic Matter Content ◽  
Understory Vegetation ◽  
Fraxinus Excelsior ◽  
Soil Parameters ◽  
Alkaline Soil ◽  
Ash Dieback ◽  
Crown Defoliation ◽  
European Ash

European ash (Fraxinus excelsior L.) dieback caused by the fungus Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, and Hosoya has been affecting European forests since 1992. The disease drives severe crown defoliation, branch loss, and finally tree mortality in European ash. The environmental factors affecting the disease process are still not fully recognized. We hypothesized that the level of crown defoliation in ash, as well as its impact on understory vegetation, will differ along the pH gradient in soil. We examined 27 ash stands in western Poland. We assessed the crown defoliation of 15 dominant and co-dominant trees, soil parameters (pH and soil organic matter contents; SOM), and also recorded the understory vegetation species composition. Most moderately and severely damaged trees occurred within the plots with a high SOM content (>7.5%) and neutral to slightly alkaline soil pH (>7.0) in the A horizon. We noted significantly lower crown defoliation in mesic sites with acidic soils and lower SOM contents. The results also showed the influence of ash crown defoliation on the species functional composition. Ash dieback led to the creation of gaps, and their colonization by other species frequently found in forest sites, especially forest-edge tall herbs.

Corncob-derived biochar decelerates mineralization of native and added organic matter (AOM) in organic matter depleted alkaline soil

Geoderma ◽  
2017 ◽  
Vol 294 ◽  
pp. 19-28 ◽  
Author(s):  
Muhammad Riaz ◽  
Mahnaz Roohi ◽  
Muhammad Saleem Arif ◽  
Qaiser Hussain ◽  
Tahira Yasmeen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Alkaline Soil

Effect of temporary flooding on cotton growth and nitrogen nutrition in soils with different organic matter levels

1987 ◽  
Vol 38 (1) ◽  
pp. 91 ◽  
Author(s):  
AW Soomro ◽  
SA Waring
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Nitrogen Nutrition ◽  
Nitrogen Concentration ◽  
Organic Matter Content ◽  
Matter Content ◽  
Growth Characteristics ◽  
Urea Nitrogen ◽  
High Organic Matter ◽  
Water Treatments

A glasshouse experiment was conducted to study the effect of temporary flooding on the growth and development of cotton (Gossypium hirsutum L. cv. Deltapine 61) and the recovery of nitrogen applied as urea fertiliser in two black earths differing in organic matter content, with three water treatments. Two floodings were applied, at 15 days after planting and at 45 days.Plant dry weight and growth characteristics of the cotton plant such as height, number of leaves, leaf area and fruiting points were greatly reduced by the flooding treatments. The cotton plants were more affected by the first than the second flooding. A greater depression in the various growth characteristics was found in the high organic matter soil than the low organic matter soil. The soils behaved differently in their interaction with the water treatments. With the control water treatment, cotton grown on the high organic matter soil produced more dry matter and assimilated more nitrogen but had a lower nitrogen concentration and apparent recovery of urea nitrogen than did cotton grown on the low organic matter soil. For the flooding treatments the low organic matter soil produced more dry matter and assimilated more nitrogen, but had a lower nitrogen concentration and a higher apparent recovery of urea nitrogen than did cotton grown on the high organic matter soil.The lower apparent recovery of urea nitrogen in the high organic matter soil during temporary flooding appears due mainly to higher loss of nitrogen by denitrification, although other mechanisms may be significant. The wider implications of the results in terms of field practice with irrigated cotton are discussed.

The fate of manganese sulphate in alkaline soils

1943 ◽  
Vol 33 (1) ◽  
pp. 18-22 ◽  
Author(s):  
R. L. Wain ◽  
B. J. Silk ◽  
B. C. Wills
Keyword(s):  
Organic Matter ◽  
Calcareous Soil ◽  
Manganese Content ◽  
Organic Matter Content ◽  
Residual Effect ◽  
Matter Content ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Time Intervals ◽  
Manganese Sulphate

1. Experiments have been made to determine the effect of treating alkaline soils with manganese sulphate on the quantities of manganese which can be extracted by N-ammonium acetate.2. Two soils of known total and ‘extractable’ manganese content were treated with manganese sulphate solution in the laboratory and re-analysed after definite time intervals. In the first of these, a calcareous soil from the College Farm, the extractable manganese decreased for 14 days after treatment, after which time manganese was again liberated, presumably due to a waterlogging effect. The extractable manganese in the second soil, a slightly alkaline soil with a high organic matter content, increased appreciably after treatment and remained at this level for the duration of the experiment.3. An experiment conducted in the field on a highly calcareous soil showed that the extractable manganese content down to a depth of 12 in., had fallen to its original level only 7 days after treatment. This behaviour is in agreement with the observations of other workers that there is little residual effect from manganese sulphate treatment for subsequent crops. The desirability of performing similar experiments on other soils is suggested.4. The effect of waterlogging and steam sterilization was to increase the quantities of extractable manganese in the soils examined.The authors wish to express their grateful thanks to Mr B. S. Furneaux, M.Sc, for the descriptions of the soils investigated, and to Dr N. H. Pizer for his valuable suggestions in the preparation of this paper. They are also indebted to Mr J. Hargrave of the Agricultural Institute, Kirton, Lines, for providing the Bourne Fen soil, and to Mr J. Tinsley, B.Sc., for pH and organic matter determinations.

scholarly journals Humic acid and nitrogen dose application in corn crop under alkaline soil conditions

2021 ◽  
Vol 25 (10) ◽  
pp. 657-663
Author(s):  
Kamran Azeem ◽  
Farah Naz ◽  
Arshad Jalal ◽  
Fernando S. Galindo ◽  
Marcelo C. M. Teixeira Filho ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Soil Conditions ◽  
Alkaline Soil ◽  
Total N ◽  
Positive Effects ◽  
N Concentration

ABSTRACT Humic acid (HA), as a bio-stimulant and a major component of organic matter (OM), can improve plant physiology, soil fertility, and nutrient availability, mainly in low OM soils. Nitrogen (N) is one of the most important nutrients that affect several metabolic and biochemical activities, leading to improved plant development. This study was conducted to investigate the combined effect of HA and N doses on soil organic matter (SOM) and total N concentration, N uptake, corn growth, and grain yield under conventional tillage at Peshawar, Pakistan. Treatments were tested in a randomized block design with four replicates arranged in a factorial scheme 3 × 4 + 1. The respective doses of HA (1.5, 3,0 and 4.5 kg ha-1) were applied at the corn sowing, whereas N doses (80, 120, 160, and 200 kg ha-1) were applied in three splits (1/3 at sowing, 1/3 at the V5 stage, and remaining 1/3 at the tasselling stage) with one control (no HA and N). The application of HA, regardless of the applied doses, had positive effects on SOM, N concentration, N uptake, corn development, and grain yield. However, the application of 4.5 kg ha-1 of HA was the most effective in promoting SOM (0.83%) and total N (0.31%), shoot biomass (10610 kg ha-1), N uptake (1.13%), and grain yield (3780 kg ha-1), even when combined with the N doses of 80, 120 and 160 kg N ha-1. Increasing N doses positively influenced SOM, N concentration, N uptake, and corn growth. The greatest grain yield was obtained at 150 kg ha-1 of N regardless of HA applied doses.

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