Field-scale solute transport in a heavy clay soil

1996 ◽  
Vol 33 (2) ◽  
pp. A60
Keyword(s):  
Solute Transport ◽  
Clay Soil ◽  
Field Scale ◽  
Heavy Clay

Field-Scale Solute Transport in a Heavy Clay Soil

1995 ◽  
Vol 31 (3) ◽  
pp. 517-526 ◽  
Author(s):  
J. J. B. Bronswijk ◽  
W. Hamminga ◽  
K. Oostindie
Keyword(s):  
Solute Transport ◽  
Clay Soil ◽  
Field Scale ◽  
Heavy Clay

Investigation into the effect of tillage on solute movement to drains through a heavy clay soil

2006 ◽  
Vol 15 (2) ◽  
pp. 94-100 ◽  
Author(s):  
C.D. Brown ◽  
V.L. Marshall ◽  
A. Deas ◽  
A.D. Carter ◽  
D. Arnold ◽  
...  
Keyword(s):  
Clay Soil ◽  
Heavy Clay ◽  
Solute Movement

Investigations in crop husbandry. III. Effect of time of application of sulphate of ammonia to wheat

1936 ◽  
Vol 26 (2) ◽  
pp. 316-327 ◽  
Author(s):  
F. H. Garner ◽  
H. G. Sanders
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Foot Rot ◽  
Plant Establishment ◽  
Poor Condition ◽  
Time Of Application ◽  
Gravelly Soil ◽  
Heavy Clay ◽  
Crop Husbandry

1. Over a period of six years seven field experiments were carried out to study the effect of the time of application of sulphate of ammonia to autumn-sown wheat.2. Three experiments were located on light gravelly soil which had been farmed highly for some years, and in those three cases sulphate of ammonia decreased yield, irrespective of time of application; the reduction in yield was of the order of 10 per cent. and is ascribed to more lodging and greater incidence of “foot-rot”.3. Three experiments were located on heavy clay soil in poor condition; in these sulphate of ammonia gave percentage increases in yield of 18, 20 and 7.4. Evidence is produced that early dressings of sulphate of ammonia do not affect germination or plant establishment, but that they tend to increase tiller formation by the end of February.

scholarly journals Reclamation of a Saline-Sodic Soil by Use of Molasses and Distillery Slops

1969 ◽  
Vol 50 (3) ◽  
pp. 209-217
Author(s):  
Raúl Pérez Escolar
Keyword(s):  
Puerto Rico ◽  
Organic Acids ◽  
Clay Soil ◽  
Mass Action ◽  
Soil Reclamation ◽  
Exchangeable Sodium ◽  
Dry Period ◽  
Action Effect ◽  
Saturation Extract ◽  
Heavy Clay

Data are presented on a laboratory study conducted to determine the effects of the use of blackstrap molasses and rum distillery slops on the reclamation of a highly saline-alkali heavy clay soil of southwestern Puerto Rico. The study revealed that even the lowest levels of distillery slops and diluted molasses, around 2.3 acre-inch, were sufficient to lower the conductivity of the soil-saturation extract from 67 mmhos/cm. to less than 3, and the exchangeable sodium percentage from 43 to less than 1 percent. It is believed that most of the Ca and Mg found in leachates of columns treated with the most slops or molasses may be attributed to the production of organic acids during the decomposition of slops and molasses. These organic acids rendered soluble the soil-free CaCO3 and MgCO3, widening the Ca and Mg:Na ratio to substitute the sodium by a mass action effect. Subjecting the soil to a dry period in between, the 6 and 7 acre-feet of water did not alter the movement of water and resulted in a complete soil reclamation.

scholarly journals Surface irrigation with saline water on a heavy clay soil in the Medjerda Valley, Tunisia.

1967 ◽  
Vol 15 (4) ◽  
pp. 281-303
Author(s):  
J.A. Van 't Leven ◽  
M.A. Haddad
Keyword(s):  
Electrical Conductivity ◽  
Clay Soil ◽  
Saline Water ◽  
Surface Irrigation ◽  
Soil Extracts ◽  
Fallow Period ◽  
Salinity Effects ◽  
Heavy Clay ◽  
Winter Crops ◽  
Resting Period

On a clay soil rich in lime, with drain spacings of 30 and 60 m, one section (A) after four crops of artichokes over a two-year period, with fairly intensive irrigation with saline water (approx 700 mm annually) showed no harmful salinity effects; in the upper 120 cm the electrical conductivity of soil extracts (EC) seldom exceeded five. On section B, with well-distributed irrigation, which was not intensive except for tomatoes in one summer, salinity was fairly uniform in the profile (EC 4-6). In section C, under continuous lucerne and with 1000-1200 mm water annually, salinity increased, especially with depth, and a fallow period was needed. In section D, under four artichoke crops followed by maize, with more intensive irrigation than in A and B, EC of the 80-120 cm layer was 7-8, and maize growth was retarded slightly. In addition to fallowing, the inclusion in rotations of winter crops and of perennials with a resting period in summer, e.g. artichokes, is recommended. A drain spacing of 60 m was adequate. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Ethylene: A Witchweed Seed Germination Stimulant

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 433-436 ◽  
Author(s):  
Robert E. Eplee
Keyword(s):  
United States ◽  
Seed Germination ◽  
Clay Soil ◽  
Soil Surface ◽  
Field Studies ◽  
The United States ◽  
Major Contributor ◽  
Single Treatment ◽  
Striga Asiatica ◽  
Heavy Clay

Ethylene gas (C2H4) was found to stimulate the germination of witchweed [Striga asiatica(L.) O. Kuntze] seeds. Ethylene diffuses greater than 120 cm horizontally from point of injection and more than 90 cm below the soil surface. Rates of 0.42 kg/ha induced germination of witchweed seeds in sandy soil; but 1.1 kg/ha is required on a heavy clay soil. Witchweed seeds respond to ethylene after a period of preconditioning that is necessary to break dormancy. Under field conditions in the Carolinas, maximum response of seeds to ethylene occurs between late April and late July. Field studies indicate a 90% reduction in viable witchweed seeds occurs where a single treatment with ethylene has been applied. The use of ethylene appears now to be a major contributor toward the eventual eradication of witchweed from the United States.

Survival and Growth of Three Hardwood Species (Fraxinus angustifolia, Ulmus laevis and U. minor) on a BottomlandSite with Heavy Clay Soil

2007 ◽  
Vol 2 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Emrah Cicek ◽  
Fahrettin Tilki ◽  
Semsettin Kulac ◽  
Murat Yilmaz ◽  
Faruk Yilmaz
Keyword(s):  
Clay Soil ◽  
Hardwood Species ◽  
Heavy Clay ◽  
Fraxinus Angustifolia ◽  
Survival And Growth ◽  
Ulmus Laevis

scholarly journals Comparison of three stream tube models predicting field-scale solute transport

1997 ◽  
Vol 1 (4) ◽  
pp. 873-893 ◽  
Author(s):  
D. Jacques ◽  
J. Vanderborght ◽  
D. Mallants ◽  
D.-J. Kim ◽  
H. Vereecken ◽  
...  
Keyword(s):  
Solute Transport ◽  
Transport Model ◽  
Local Scale ◽  
Transfer Model ◽  
Transport Parameters ◽  
Field Scale ◽  
Stream Tube ◽  
Solute Dispersion ◽  
Measurement Volume ◽  
Piston Flow

Abstract. In this paper the relation between local- and field-scale solute transport parameters in an unsaturated soil profile is investigated. At two experimental sites, local-scale steady-state solute transport was measured in-situ using 120 horizontally installed TDR probes at 5 depths. Local-scale solute transport parameters determined from BTCs were used to predict field-scale solute transport using stochastic stream tube models (STM). Local-scale solute transport was described by two transport models: (1) the convection-dispersion transport model (CDE), and (2) the stochastic convective lognormat transfer model (CLT). The parameters of the CDE-model were found to be lognormally distributed, whereas the parameters of the CLT model were normally distributed. Local-scale solute transport heterogeneity within the measurement volume of a TDR-probe was an important factor causing field-scale solute dispersion. The study of the horizontal scale-dependency revealed that the variability in the solute transport parameters contributes more to the field-scale dispersion at deeper depths than at depths near the surface. Three STMs were used to upscale the local transport parameters: (i) the stochastic piston flow STM-I assuming local piston flow transport, (ii) the convective-dispersive STM-II assuming local CDE transport, and (iii) the stochastic convective lognormal STM-III assuming local CLT. The STM-I considerably underpredicted the field-scale solute dispersion indicating that local-scale dispersion processes, which are captured within the measurement volume of the TDR-probe, are important to predict field-scale solute transport. STM-II and STM-III both described the field-scale breakthrough curves (BTC) accurately if depth dependent parameters were used. In addition, a reasonable description of the horizontal variance of the local BTCs was found. STM-III was (more) superior to STM-II if only one set of parameters from one depth is used to predict the field-scale solute BTCs at several depths. This indicates that the local-scale solute transport process, as measured with TDR in this study, is in agreement with the CLT-hypothesis.

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