scholarly journals Effect of Pot Lip Shape on Soil Surface Evaporative Losses

1987 ◽  
Vol 5 (2) ◽  
pp. 41-45
Author(s):  
T.H. Whitlow ◽  
L.Y. Mudrak
Keyword(s):  
Wind Tunnel ◽  
Soil Surface ◽  
Growth Chamber ◽  
The Third ◽  
Loam Soil

Small pots containing a loam soil were monitored in a growth chamber and wind tunnel to determine the effect of 13 different lip shapes on evaporation from the soil surface. In the growth chamber, pots with modified lips showed evaporative losses ranging from 52-95% of the unmodified control during the first 24 hrs following watering. The same trend was observed during the second 24 hrs following watering but not during the third 24 hr period. In the wind tunnel, nine treatments showed significant reductions in evaporation in comparison to the control 24 hrs after watering; no differences were observed after three days of drying.

Laboratory and field studies on the degradation of fipronil in a soil

Soil Research ◽  
2002 ◽  
Vol 40 (7) ◽  
pp. 1095 ◽  
Author(s):  
Guang-Guo Ying ◽  
Rai Kookana
Keyword(s):  
Soil Moisture ◽  
Half Life ◽  
Soil Moisture Content ◽  
Soil Surface ◽  
Field Studies ◽  
Transformation Product ◽  
Laboratory Studies ◽  
The Third ◽  
High Soil Moisture ◽  
Sulfone Derivatives

Degradation of a new insecticide/termiticide, fipronil, in a soil was studied in the laboratory and field. Three metabolites of fipronil (desulfinyl, sulfide, and sulfone derivatives) were identified from soils after treatment. Laboratory studies showed that soil moisture content had a great effect on the degradation rate of fipronil and products formed. High soil moisture contents (>50%) favored the formation of a sulfide derivative of fipronil by reduction, whereas low soil moisture (<50%) and well-aerated conditions favored the formation of fipronil sulfone by oxidation. Microorganisms in soil accelerated the degradation of fipronil to sulfide and sulfone derivatives. The third transformation product, a desulfinyl derivative, was formed by photodecomposition of fipronil in water and on the soil surface under sunlight. The desulfinyl derivative degraded rapidly in field soils with a half-life of 41–55 days compared with an average half-life of 132 days for fipronil. The half-life of the 'total toxic component' (fipronil and its metabolites) in field soil was 188 days on average.

Examination of the Penetration of Enteric Viruses in Soils under Simulated Conditions in the Laboratory

1985 ◽  
Vol 17 (10) ◽  
pp. 197-199 ◽  
Author(s):  
P. H. Jørgensen
Keyword(s):  
Sewage Sludge ◽  
Unsaturated Soil ◽  
Sandy Loam ◽  
Soil Column ◽  
Enteric Viruses ◽  
Soil Surface ◽  
Coxsackievirus B3 ◽  
Soil Columns ◽  
Sand Column ◽  
Loam Soil

In two different unsaturated soil columns percolated with artificial rainwater under simulated aerated conditions, transport of coxsackievirus B3 and adenovirus 1 below 3.5 cm under the soil surface could not be demonstrated. The viruses were applied to the columns as seeded sewage sludge. Under saturated conditions transport of water-suspended coxsackievirus B3 was faster in a soil column with sandy loam soil than in a diluvial sand column.

Factors Involved in Alachlor Injury to the Potato (Solanum tuberosum)

Weed Science ◽  
1977 ◽  
Vol 25 (6) ◽  
pp. 482-486 ◽  
Author(s):  
J.N. Belote ◽  
T.J. Monaco
Keyword(s):  
Solanum Tuberosum ◽  
Soil Surface ◽  
Growth Chamber ◽  
Herbicide Application ◽  
Time Of Application ◽  
Plant Emergence ◽  
Chamber Studies ◽  
Growth Chamber Studies

Results from greenhouse and growth chamber studies indicated that alachlor [2-chloro-2′,6-diethyl-N-(methoxymethyl) acetanilide] injury to ‘Superior’ potatoes (Solanum tuberosumL.) was related to time of herbicide application and temperature. Injury to the ‘Superior’ cultivar was observed when alachlor was applied just before potato emergence. Necrosis of shoots near the soil surface, shoot dieback, stem swelling, leaf crinkle, and plant stunting were characteristic symptoms of alachlor injury. Cool temperatures appeared to intensify the injury. ‘Superior’ potatoes outgrew injury within 41 days after treatment. Herbicide placement studies in the growth chamber suggested that alachlor or its metabolites were absorbed by the shoots of emerging ‘Superior’ potatoes. Under growth chamber conditions the ‘Katahdin’ cultivar was injured by preemergence applications of alachlor when the herbicide was applied just before plant emergence. Injury symptoms were similar to those observed on the ‘Superior’ cultivar. ‘Pungo’ and ‘Norchip’ potatoes were tolerant to preemergence applications of the herbicide regardless of time of application.

Subsurface Application and Shallow Incorporation of Herbicides on Cotton

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 494-498 ◽  
Author(s):  
A. F. Wiese ◽  
E. B. Hudspeth
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Sandy Loam ◽  
Soil Surface ◽  
Sandy Loam Soil ◽  
Soil Types ◽  
Loam Soil

In a 3-year study on four soil types, subsurface application just ahead of a planter with a device that removed the top from the bed, applied a band of spray, and covered the band with soil reduced weed control in cotton (Gossypium hirsutum L.) obtained with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne), 3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea (norea), dimethyl-2,3,5,6-tetrachloroterephthalate (DCPA), and 1,1-dimethyl-3(α,α,α,-trifluoro-m-tolyl)urea (fluometuron) compared to applications on the soil surface. This machine improved weed control with α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). Shallow incorporation, with two helical blades, after planting increased weed control with trifluralin, diuron, and DCPA by 10% or more over the surface applications. This incorporator increased weed control obtained with prometryne and norea 5%. Very shallow incorporation, with metal tines, after planting improved weed control obtained with trifluralin and DCPA 18 and 11%, respectively. Weed control with norea was increased 7%, but metal tines did not appreciably affect weed control obtained with prometryne, diuron, or fluometuron. Compared to surface applications, incorporation increased cotton injury with diuron, norea, prometryne, and fluometuron on sandy loam soil.

Degradation and Leaching of Methazole in Soil

Weed Science ◽  
1977 ◽  
Vol 25 (4) ◽  
pp. 304-308 ◽  
Author(s):  
F.E. Brockman ◽  
W.B. Duke
Keyword(s):  
Environmental Conditions ◽  
Sandy Loam ◽  
Total Radioactivity ◽  
Growth Chamber ◽  
Simulated Rainfall ◽  
Soil Columns ◽  
Rainfall Simulator ◽  
Loam Soil ◽  
Original Amount ◽  
Over Time

The degradation and leaching of methazole [2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione] and metabolites in Elmwood sandy loam soil over time in response to average spring environmental conditions was studied by using soil columns placed on a rainfall simulator in an environmental growth chamber. Methazole was degraded to 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU) and 3-(3,4-dichlorophenyl) urea (DCPU) over a 6-week period following methazole application, during which the soil columns received simulated rainfall of 1.27 cm every fourth day. Methazole level decreased to 27% of the original amount while DCPMU and DCPU levels increased to 53% and 1%, respectively. Of the total radioactivity remaining in the soil columns after 44 days and after 14 cm rainfall, approximately 80% remained above a depth of 6.35 mm.

Wind erosion of microplastics from soils: linking soil surface properties with microplastic flux

2020 ◽  
Author(s):  
Annie Ockelford ◽  
Joanna Bulalrd ◽  
Cheryl McKenna-Neuman ◽  
Patrick O'Brien
Keyword(s):  
Surface Roughness ◽  
Wind Tunnel ◽  
Wind Erosion ◽  
Soil Surface ◽  
Surface Characteristics ◽  
Test Material ◽  
Mineral Particle ◽  
Test Bed ◽  
Transport Pathway ◽  
Soil Surface Roughness

&lt;p&gt;Recent studies of soils in the Alps and Middle East indicate airborne transport of microplastics following wind erosion may be significant.&amp;#160; Where microplastics have been entrained by wind they show substantial enrichment ratios compared to mineral particle erosion.&amp;#160; Further, microplastic shape affects enrichment ratios with those for fibres greater than for microbeads which may reflect the lower density and asymmetric shape of microplastics compared to soil particles. This suggests that terrestrial to atmospheric transfer of microplastics could be a significant environmental transport pathway. However, currently we have very little understanding of how the properties, in particular the surface characteristics, of the sediment which they are being eroded from affects their entrainment potential.&lt;/p&gt;&lt;p&gt;This paper reports wind tunnel studies run to explore the impacts of soil surface characteristics on microplastic flux by wind erosion.&amp;#160; Experiments were performed in a boundary layer simulation wind tunnel with an open-loop suction design.&amp;#160; The tunnel has a working section of 12.5m x 0.7m x 0.76m and is housed in an environmental chamber which, for this study, was held constant at 20 &lt;sup&gt;o&lt;/sup&gt;C and 20% RH. In experiments two types of low density microplastic (microbeads and fibres) were mixed into a poorly-sorted soil containing 13% organics.&amp;#160; The polyethylene microbeads had a size range of 212-250 microns and density of 1.2 g cm&lt;sup&gt;3&lt;/sup&gt; and the polyester fibres were 5000 microns long and 500-1000 microns in width with a density of 1.38 g cm&lt;sup&gt;3&lt;/sup&gt;.&amp;#160; Microplastics were mixed into the sediment in concentrations ranging from 40-1040 mg kg&lt;sup&gt;-1&lt;/sup&gt;. For each experiment, test surfaces were prepared by filling a 1.0m x 0.35m x &amp;#160;0.025m metal tray with the given mixture of test material which was lowered into the wind tunnel such that it was flush with the tunnel floor and levelled. The wind tunnel was then switched on and run with increasing wind speeds using 0.25 m s&lt;sup&gt;-1&lt;/sup&gt; increments until continuous saltation occurred.&amp;#160; Soil surface roughness was scanned prior to and after each experiment using a high resolution laser scanner (0.5mm resolution over the entire test section). &amp;#160;Transported soil and microplastic particles were captured in bulk using a 2 cm wide by 40 cm tall Guelph-Trent wedge trap that was positioned 2 m downwind of the test bed.&amp;#160;&lt;/p&gt;&lt;p&gt;Discussion concentrates on linking the changes in soil surface topography to the magnitude of microplastic flux where data shows that there is a correlation between the development of the soil surfaces and overall microplastic flux.&amp;#160; Specifically, soil surface roughness is seen as a significant control on microplastic flux where it has a greater overall effect on microplastic fibre flux as compared to the microplastic beads.&amp;#160; The outcome of this research is pertinent to developing understanding surrounding the likely controls and hence propensity of microplastics to be entrained from soil by wind erosion. &amp;#160;&lt;/p&gt;

Nitrogen dynamics under growth chamber conditions as influenced by method of alfalfa termination 2. Plant-available N release

1998 ◽  
Vol 78 (2) ◽  
pp. 261-266 ◽  
Author(s):  
R. M. Mohr ◽  
H. H. Janzen ◽  
M. H. Entz
Keyword(s):  
Nitrogen Uptake ◽  
N Uptake ◽  
Soil Surface ◽  
Growth Chamber ◽  
Nitrogen Accumulation ◽  
Herbicide Application ◽  
Hordeum Vulgare L ◽  
Available N ◽  
N Release ◽  
Barley Crop

Herbicide application has been proposed as an alternative to tillage for termination of established alfalfa (Medicago sativa L.) stands but it may alter the pattern and amount of N released from alfalfa residues. A controlled environment study was conducted to investigate the effect of termination technique on the availability of N to four barley (Hordeum vulgare L.) crops. Four treatments consisting of a factorial combination of two termination methods (chemical, mechanical) and two methods of residue placement (surface, incorporated) were established. Nitrogen uptake by the four consecutive crops of barley was measured during a 125-d period after termination. Termination method, particularly residue placement, strongly affected N release from alfalfa residues. Nitrogen accumulation by the initial barley crop accounted for >60% of cumulative N uptake in incorporated treatments compared with 39% and 24% for herbicide and tillage treatments in which alfalfa residue was surface applied. Herbicide application also slightly increased N uptake by the initial barley crop. Nitrogen uptake by subsequent barley crops was not affected by termination method; however, cumulative N uptake remained substantially greater for incorporated treatments throughout the 125 d experiment. Effects of residue particle size on N release from alfalfa residues were small. These results suggest that herbicide termination in which residue is retained on the soil surface may reduce the short-term plant-available N supply. Provided that mineralization is sufficient to meet the N needs of subsequent crops, maintaining a smaller reservoir of soil inorganic N may be beneficial in reducing the potential for leaching or denitrification losses. Key words: Plant-available N, termination method, alfalfa, herbicide, tillage, growth chamber

Ammonia volatilization from surface-applied livestock slurry as affected by slurry composition and slurry infiltration depth

2006 ◽  
Vol 144 (3) ◽  
pp. 229-235 ◽  
Author(s):  
S. G. SOMMER ◽  
L. S. JENSEN ◽  
S. B. CLAUSEN ◽  
H. T. SØGAARD
Keyword(s):  
Soil Water ◽  
Dry Matter ◽  
Sandy Loam ◽  
Soil Water Potential ◽  
Soil Surface ◽  
Pig Slurry ◽  
Fertilizer Value ◽  
Loam Soil ◽  
Water Values ◽  
Slurry Composition

Volatilization of ammonia (NH3) from slurry applied in the field is considered a risk to the environment and reduces the fertilizer value of the slurry. To reduce volatilization a better understanding of the slurry–soil interaction is needed. Therefore, the present study focuses on measuring NH3 volatilization as affected by differences in infiltration. Livestock slurries with different dry matter (DM) composition and viscosity were included in the experiments by using untreated cattle and pig slurry, pig slurry anaerobically digested in a biogas plant and pig slurry anaerobically digested and physically separated. NH3 volatilization was measured using dynamic chambers and related to infiltration of the livestock slurries in the soil by measuring chloride (Cl−) and Total Ammoniacal Nitrogen (TAN=ammonium (NH4+)+NH3) concentrations in soil at different depths from 0·5 to 6·0 cm from the soil surface. The slurries were applied to sandy and sandy-loam soils packed in boxes within the chambers. There were no significant differences in relative volatilization of NH3 from untreated cattle and pig slurries, but anaerobic digestion of pig slurry increased volatilization due to increases in pH. However, physical separation of the digested slurry reduced the volatilization compared with untreated slurry, due to increased infiltration. In general, the volatilization decreased significantly with increased infiltration. The present study shows that NH3 volatilization from applied slurry can be related to infiltration and that infiltration is related to slurry composition (i.e. DM content and particle size distribution) and soil water content. The infiltration of liquid (measured by Cl− infiltration) was affected by soil water potential, therefore, Cl− infiltrated deeper into the sandy loam soil than the sandy soil at similar gravimetric soil water values. Dry matter (DM) and large particles (>1 mm) of the slurry reduced infiltration of liquid. A high proportion of small particles (<0·025 mm) facilitated infiltration of TAN.

EFFECT OF NONERODIBLE AGGREGATES AND WHEAT STUBBLE ON INITIATION OF SOIL DRIFTING

1970 ◽  
Vol 50 (1) ◽  
pp. 31-34 ◽  
Author(s):  
FREDERICK BISAL ◽  
W. S. FERGUSON
Keyword(s):  
Wind Tunnel ◽  
Wind Velocity ◽  
Soil Aggregates ◽  
Soil Surface ◽  
Wheat Stubble ◽  
The Relationship

The wind velocity required to initiate movement of soil with varying amounts of standing wheat stubble and varying proportions of erodible and nonerodible soil aggregates was determined in a wind tunnel. The relationship between these variables was calculated as logeI = 6.0438 + 0.0001774 S + 0.02332 C where I is the initiating velocity in cm/sec as measured at a height of 30.5 cm above the soil surface, S is the amount of standing wheat stubble (approximately 15 cm tall) in kg/ha, and C is the percentage of soil aggregates greater than 1 mm in diameter in a soil sample.The wind velocity required to initiate erosion is proposed as an index of erodibility of farm fields.

Sign in / Sign up

Export Citation Format

Share Document