Biochar and potassium humate shift the migration, transformation and redistribution of urea-N in salt-affected soil under drip fertigation: soil column and incubation experiments

Abstract Accurate measurements of CO2 efflux from soils are essential to understand dynamic changes in soil carbon storage. Column incubation experiments are commonly used to study soil water and solute transport; however, the use of column incubation experiments to study soil CO2 efflux has seldom been reported. In this study, a 150-day greenhouse experiment with two treatments (no-tillage and tillage soils) was conducted to evaluate the applicability of soil column incubation experiments to study CO2 efflux. Both the chamber measurement and the gradient method were used, and results from the two methods were consistent: tillage increased soil cumulative CO2 efflux during the incubation period. Compared with fieldwork, incubation experiments can create or precisely control experimental conditions and thus have advantages for investigating the influence of climate factors or human activities on CO2 efflux. They are superior to bottle incubation because soil column experiments maintain a soil structure that is almost the same as that in the field, and thus can facilitate analyses on CO2 behaviour in the soil profile and more accurate evaluations of CO2 efflux. Although some improvements are still required for column incubation experiments, wider application of this method to study soil CO2 behaviour is expected.

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Impact of Mineral Fertilizers with or without Bio-Fertilizers or Potassium Humate on some Soil Properties, Yield and Quality of Pea Plants Under Salt Affected Soil Conditions

Journal of Agricultural Chemistry and Biotechnology ◽

10.21608/jacb.2019.36785 ◽

2019 ◽

Vol 10 (1) ◽

pp. 19-27

Author(s):

H. Khafagy ◽

Marwa Ahmed ◽

Seham Abdel-Azeem

Keyword(s):

Soil Properties ◽

Mineral Fertilizers ◽

Soil Conditions ◽

Potassium Humate ◽

Salt Affected Soil ◽

Yield And Quality

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ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

Anbar Journal of Agricultural Sciences ◽

10.32649/ajas/2020/2 ◽

2020 ◽

pp. 15-27

Keyword(s):

Electrical Conductivity ◽

Humic Acids ◽

Release Rate ◽

Release Kinetics ◽

Sodium Adsorption Ratio ◽

Salt Affected Soil ◽

Two Factors ◽

Dissolved Ions ◽

Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

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ANDROST-5-ENE-3β,17β-DIOL IN OVARY OF POST-MENOPAUSAL HYPEROESTROGENIC WOMEN

Acta Endocrinologica ◽

10.1530/acta.0.0580364 ◽

1968 ◽

Vol 58 (3) ◽

pp. 364-376 ◽

Cited By ~ 5

Author(s):

S. Pesonen ◽

M. Ikonen ◽

B-J. Procopé ◽

A. Saure

Keyword(s):

Ovarian Tissue ◽

Cortical Layer ◽

Vaginal Smears ◽

Incubation Experiments ◽

Cell Groups ◽

Post Menopause ◽

Reducing Activity ◽

Post Menopausal ◽

One Year

ABSTRACT The ovaries of ten patients, at least one year after the post-menopause, were incubated with two Δ5-C19-steroids and also studied histochemically. All these patients had post-menopausal uterine bleeding and increased oestrogen excretion of the urine. The urinary estimations of gonadotrophins, 17-KS, 17-OHCS and pregnanediol were carried out on all patients. Vaginal smears were read according to Papanicolaou, and the endometrium and ovaries were studied histologically. The incubation experiments indicate the presence of Δ5-3β-hydroxysteroid-dehydrogenase. When androst-5-ene-3β,17β-diol was used as precursor the formation of testosterone occurred without any concomitant production of DHA and/or androstenedione. This seems to indicate the possible role of the Δ5-pathway in the formation of testosterone by post-menopausal ovarian tissue. The histochemical reactions indicated a reducing activity on NADH, lactate and glucose-6-phosphate, in certain corpora albicantia, atretic follicles and in diffuse thecoma regions in the cortical layer of the ovary. Steroid-3β-ol-dehydrogenase and β-hydroxybutyrate-dehydrogenase were found only at the edges of certain corpora albicantia, in some individual stroma cell groups and in some atretic follicles. Our studies, both biochemical and histochemical, suggest that the observed increase in the urinary oestrogens of the patients studied might in part at least, be of ovarian origin. This opinion is also supported by the postoperative oestrogen values.

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