Interactions between water flow and microplastics in silt loam and loamy sand

2021 ◽  
Author(s):  
Xuguang Xing ◽  
Miao Yu ◽  
Tianjiao Xia ◽  
Li Ma
Keyword(s):  
Water Flow ◽  
Loamy Sand ◽  
Silt Loam

scholarly journals Using Soil Solution Monitoring to Determine the Effects of Irrigation Management and Fertigation on Nitrogen Availability in High-density Apple Orchards

1998 ◽  
Vol 123 (4) ◽  
pp. 706-713 ◽  
Author(s):  
D. Neilsen ◽  
P. Parchomchuk ◽  
G.H. Neilsen ◽  
E.J. Hogue
Keyword(s):  
Soil Solution ◽  
Irrigation Water ◽  
Root Zone ◽  
Irrigation Management ◽  
Sprinkler Irrigation ◽  
Loamy Sand ◽  
N Availability ◽  
Silt Loam ◽  
N Concentration ◽  
Loam Soil

Direct application of fertilizers in irrigation water (fertigation) is an efficient method of supplying nutrients to fruit trees. Information is needed on the relationship between irrigation and N inputs on N availability in order to target nutrient applications to meet plant demands. Soil solution was collected from permanently installed suction lysimeters and NO3-N concentration was measured over the growing season in three experiments: 1) comparison of sprinkler irrigation + broadcast fertilizer with weekly fertigation + daily drip irrigation; 2) comparison of (NH4)2SO4 or Ca(NO3)2 as N sources under daily fertigation; and 3) comparisons of combinations of irrigation applied at either fixed rates or to meet evaporative demand and fertilizer (Ca(NO3)2) applied daily either at fixed rates or to maintain a given concentration in the fertigation solution in two soil types—loamy sand and silt loam. Trials are located in high density apple plantings of either `Gala' or `Empire' apple (Malus × domestica Borkh.) on M.9 rootstock. Nitrate-N concentration in the soil solution measured at 30 cm deep remained higher, over more of the growing season, for weekly fertigation + daily drip irrigation than for a single broadcast fertilizer application + sprinkler irrigation. With daily Ca(NO3)2 fertigation, soil solution NO3- N concentrations increased and decreased rapidly with the onset and end of fertigation respectively, remained relatively constant during the intervening period and were directly proportional to either the amount of N or the amount of irrigation water added. Daily fertigation with (NH4)2SO4 resulted in less control of NO3-N availability in the root-zone than with Ca(NO3)2, which may be problematic for precise timing of N nutrition. Except for the fixed irrigation rate applied to the loamy sand soil, soil solution NO3-N concentrations at 30 cm beneath the emitter were similar to average concentrations in the fertigating solution, for all methods of irrigation management in both soil types. Elevated NO3-N concentrations in soil solution below the root zone (75 cm deep) were detected in the loamy sand regardless of methods of N application and irrigation although there was some evidence of less leaching to this depth, under scheduled irrigation. In the silt loam soil, considerably lower concentrations of NO3-N were found beneath the root zone than at 30 cm deep for all of irrigation procedures and frequently there was insufficient water moving to 75 cm to provide sample. Tree growth in the loamy sand was less than in the silt loam soil; was limited by low application of irrigation water in 1992 and 1993; was unaffected by NO3-N concentration in the root zone, indicating that N inputs could be minimized by adding N to maintain concentrations of 75 μg·mL-1 or possibly less. Nitrogen inputs may also be reduced if fertilizer N and irrigation water could be retained within the root zone. For coarse-textured soils this will require precise additions of water and possibly soil amendments to improve water holding capacity.

scholarly journals Evaluation of MACRO model by short-term water and solute transport simulation in Maury silt loam soil

2011 ◽  
Vol 51 (No. 3) ◽  
pp. 110-123 ◽  
Author(s):  
H. Merdun ◽  
V.L. Quisenberry
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Chloride Transport ◽  
Effective Diffusion ◽  
Diffusion Path ◽  
Silt Loam ◽  
Short Term ◽  
Silt Loam Soil ◽  
Diffusion Path Length ◽  
Loam Soil

Modeling preferential flow has been a concern of many academic fields in the past 30 years all over the world and helps to prevent groundwater contamination. A dual-porosity model, MACRO, was evaluated for short-term (less than 2 days) simulation of water flow and non-reactive solute (chloride) transport through the profile of six plots in well-structured Maury silt loam soil. Water flow in micropores is calculated by the Richards’ equation while simple gravity flow is assumed in the macropores. Solute transport in the micropores is calculated by the convection-dispersion equation (CDE) while the dispersion and diffusion in the CDE is neglected for the solute transport in the macropores. The applied water and chloride reached the bottom of the profile during the 2 and 1-hour(s) application periods in studies 2 and 3, respectively. There is a strong indication of macropore flow in this soil. Based on the statistical criteria, the model accurately simulated water flow and solute transport with depth and time in all plots. The mean values of three statistical parameters (coefficient of residual mass, model efficiency, and correlation coefficient) for water and chloride transport were –0.0014, 0.791, 0.903 and 0.0333, 0.923, 0.956, respectively. Preliminary studies showed that the model could not simulate flow and transport well enough with the one-domain flow concept. In the two-domain flow, effective diffusion path-length, boundary hydraulic conductivity, and boundary soil water pressure were the three most important parameters that control flow and transport between the two domains. The effective diffusion path-length represented the structural development with depth in the Maury silt loam soil.

scholarly journals Inoculation and Soil Texture Effects on Yield and Yield Components of Mungbean

2018 ◽  
Vol 10 (9) ◽  
pp. 6 ◽  
Author(s):  
Andre A. Diatta ◽  
Wade E. Thomason ◽  
Ozzie Abaye ◽  
Larry J. Vaughan ◽  
Thomas L. Thompson ◽  
...  
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Soil Texture ◽  
Loamy Sand ◽  
Plant Residue ◽  
Silt Loam ◽  
Sand Soil ◽  
Loamy Sand Soil ◽  
Group I ◽  
Number Of Seeds

Mungbean [Vigna radiata (L.) Wilczek] is a short-duration and relatively drought-tolerant crop grown predominantly in the tropics. This grain legume can improve soil fertility through biological nitrogen (N) fixation. To assess the effects of Bradyrhizobium (group I) inoculation on yield and yield attributes of mungbean, a greenhouse study was conducted during Fall 2016 with two mungbean cultivars (‘Berken’ and ‘OK2000’), two inoculum treatments (inoculated and uninoculated), and two soil textures (loamy sand and silt loam). Pots were laid out in a completely randomized design and treatment combinations were replicated seven times. The main effects of cultivar and soil texture significantly (P ≤ 0.05) affected mungbean seed weight and plant residue mass. Seed yield (13%), plant residue (22%), and protein content (6%) of OK2000 were significantly higher than Berken cultivar. A 31% seed yield and 40% plant residue increase were recorded on silt loam soil compared to loamy sand soil. Significant increase in plant height (18%) and number of pods per plant (21%) were also recorded when mungbean plants were grown on silt loam compared to loamy sand soil. Bradyrhizobium inoculation significantly increased the number of pods per plant, the number of seeds per plant, and seed yield. [Cultivar × inoculation] and [cultivar × soil texture] interactions had significant (P ≤ 0.05) effects on number of seeds per pods and plant height, respectively. Understanding the agronomic practices and soil physical properties that may limit mungbean production could help in optimizing its establishment and growth in non-traditional growing areas.

Mobility of Herbicides in Soil Columns Under Saturated- and Unsaturated-Flow Conditions

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 579-584 ◽  
Author(s):  
Jerome B. Weber ◽  
David M. Whitacre
Keyword(s):  
Unsaturated Flow ◽  
Sandy Loam ◽  
High Water ◽  
Loamy Sand ◽  
Silt Loam ◽  
Flow Conditions ◽  
Soil Columns ◽  
Saturated Flow

Under unsaturated-flow conditions, bromacil (5-bromo-3-sec-butyl-6-methyluracil) was considerably more mobile than buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxyl-1-methyl-2-imidazolidinone}. Because of their high water solubilities, both herbicides were much more mobile than atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), prometon [2,4-bis (isopropylamino)-6-methoxy-s-triazine], or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea]. Under saturated-flow conditions, buthidazole was leached through Lakeland loamy sand in slightly greater amounts than tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} or CN-10-3510 (formerly VEL 3510) {1-β,β-dimethoxyl-1-methyl-3-[5-(1,1-dimethylethyl)-1,3, 4-thiadiazol-2-yl] urea}. Distribution of the three herbicides in the leached soil was similar and relatively uniform. In Lakeland loamy sand, 30 times as much tebuthiuron was leached under saturated-flow conditions as under unsaturated-flow conditions. Intermittent saturated-unsaturated-flow conditions resulted in four times as much leaching of tebuthiuron as unsaturated flow alone. Only one-tenth as much tebuthiuron leached under intermittent saturated-unsaturated-flow conditions as under saturated-flow conditions. Tebuthiuron added to Lakeland soil and oven-dried was retained in significantly greater amounts than when added to moist Lakeland soil. Low amounts of tebuthiuron leached through Lakeland loamy sand, Portsmouth sandy loam, and Rains silt loam, but high amounts leached through Davidson clay. Greater amounts of the herbicide were retained in the surface zones of the three former soils, but the inverse was the case for the Davidson soil.

Simulating the vertical transition of soil textural layers in north-western China with a Markov chain model

Soil Research ◽  
2013 ◽  
Vol 51 (3) ◽  
pp. 182 ◽  
Author(s):  
Danfeng Li ◽  
Ming'an Shao
Keyword(s):  
Layer Thickness ◽  
Sandy Loam ◽  
Loamy Sand ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Textural Type ◽  
Log Normal ◽  
Log Normal Distribution

The heterogeneity of textures in soil profiles is important for quantifying the movement of water and solutes through soil. Soil-profile textures to a depth of 300 cm were investigated at 100 sites in a 100-km2 area in the central region of the Heihe River system, where oases coexist with widespread deserts and wetland. The probability distribution of textural-layer thickness was quantified. The vertical transition of the soil textural layers was characterised by a Markov chain–log-normal distribution (MC-LN) model based on the probability of one textural type transitioning to another. Nine types of textural layers were observed: sand, loamy sand, sandy loam, silt loam, loam, clay loam, silty clay loam, silty clay, and clay. Sand was the most frequent in the profiles, whereas silt loam and clay were rare. The layers of sand and silty clay were relatively thick, and the layers of loam and clay were relatively thin. The coefficients of variation ranged from 36–87%, indicating moderate variation in the layer thickness of each textural type. The soil profile was characterised as a log-normal distribution. A χ2 test verified the Markov characteristic and the stability of the vertical change of soil textural layers. Realisations of the soil textural profiles were generated by the MC-LN model. A Monte Carlo simulation indicated that the simulated mean layer thickness of each textural type agreed well with the corresponding field observations. Element values of the transition probability matrix of the textural layers simulated by the MC-LN model deviated <12.6% from the measured values, excluding the data from the layers of clay and silt loam. The main combinations of upper to lower textural layers in the study area were loamy sand and sand (or sandy loam), sandy loam and sand (or loamy sand and loam), loam and clay loam, clay loam (or silty clay) and silty clay loam, and silty clay loam and silty clay. The MC-LN model was able to accurately quantify the vertical changes of textures in the soil profiles. This study will aid in quantification of water and solute transport in soils with vertical heterogeneity of soil textural layers.

Mobility and Distribution of Buthidazole and Metabolites in Four Leached Soils

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 585-588 ◽  
Author(s):  
Jerome B. Weber ◽  
Thomas F. Peeper
Keyword(s):  
Sandy Soils ◽  
Loamy Sand ◽  
Silt Loam ◽  
Soil Columns

Buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl}-4-hydroxyl-1-methyl-2-imidazolidinone} was incubated for 30 days and then leached through Norfolk loamy sand, Lakeland loamy sand, Davidson clay, and Alamance silt loam soils. Similar amounts of the herbicide leached through all of the soils, but distribution in the soils varied greatly.14C-buthidazole distribution in the Lakeland and Norfolk sandy soils was relatively uniform throughout the soil columns. In the Alamance silt loam and Davidson clay, much greater amounts of buthidazole were found in the upper soil zones than in the lower zones. Six metabolites of buthidazole (dihydroxy, desmethyl dihydroxy, dehydrate, methylurea, urea, and amine) were distributed in varying amounts in each of the soils.

Distribution of Arsenic in Soil Profiles after Repeated Applications of MSMA

Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 272-275 ◽  
Author(s):  
A. E. Hiltbold ◽  
B. F. Hajek ◽  
G. A. Buchanan
Keyword(s):  
Sandy Loam ◽  
Soil Column ◽  
Loamy Sand ◽  
Soil Types ◽  
Soil Profiles ◽  
Silt Loam ◽  
Column Studies ◽  
Fine Sandy Loam ◽  
Surface Horizon ◽  
Repeated Applications

Arsenic as MSMA (monosodium methanearsonate) was applied to three soil types over a 6-year period. Percentage recovery of applied arsenic averaged 67, 57, and 39% in Hart-sells fine sandy loam, Decatur silt loam, and Dothan loamy sand soils, respectively. Essentially all of the arsenic recovered in the soils occurred in the plow layer with no evidence of leaching into deeper zones. Batch-equilibrium and soil-column studies in the laboratory indicated that the rate of MSMA movement through the surface horizon would be fastest in Dothan loamy sand and slowest in Decatur silt loam.

Effect of Soil Type and Irrigation Method on Lateral Movement of Cycloate

Weed Science ◽  
1971 ◽  
Vol 19 (6) ◽  
pp. 709-711 ◽  
Author(s):  
Charles E. Stanger ◽  
Arnold P. Appleby
Keyword(s):  
Soil Type ◽  
Furrow Irrigation ◽  
Loamy Sand ◽  
Silt Loam ◽  
Lateral Movement ◽  
Sand Soil ◽  
Echinochloa Crusgalli ◽  
Soil Movement ◽  
Irrigation Method ◽  
Loamy Sand Soil

In greenhouse studies, lateral movement and toxicity ofS-ethyl N-ethylthiocyclohexanecarbamate (cycloate) to barnyardgrass (Echinochloa crusgalli(L.) Beauv.) was greater in a loamy sand soil than in two silt loam soils when cycloate was applied by subsurface line injection. Greatest movement and effectiveness resulted from injection into a preirrigated soil without further irrigation. Lateral movement was adequate under furrow irrigation, but the treated band was displaced. Movement of the cycloate was inadequate under sprinkler or subirrigation. Cycloate was more effective when mechanically mixed with the soil than when injected. Cycloate moved more readily in moist soils than in dry soils. When cycloate was injected into a dry loamy sand soil, movement was similar whether irrigation was applied immediately or after 24 hr.

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