Triallate Mobility in Soils

Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 541-544 ◽  
Author(s):  
G. B. Beestman ◽  
J. M. Deming

Laboratory studies were conducted to measure the relative volatility of triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate] from soils and to determine the effect of surfactants on triallate mobility. Significant volatilization occurred from continuously moist soils under constant air exposure but triallate did not volatilize more rapidly than herbicides which do not respond to incorporation. Volatilization rates from Ray silt soil fell in the order of propachlor (2-chloro-N-isopropylacetanilide) > triallate > alachlor [2-chloro-2′, 6′-diethyl-N-(methoxymethyl)acetanilide] and from Drummer silty clay loam were propachlor > alachlor > triallate. In suspension studies soils reversibly adsorbed 93 to 98% of the triallate in aqueous solution. With soil at field moisture capacity, the concentration of triallate in soil solution was 13 ppbw without surfactant and 14 ppbw with 3 parts emulsifier blend to 1 part of triallate (w/w). With this level of emulsifier 92% of triallate applied to the soil surface remained in the upper 3 cm of soil following a 15.2-cm simulated rainfall. Without surfactant 99% remained in the upper 3 cm of soil. Lower triallate mobility in moist soils observed in this study coupled with the strong dependence of triallate bioactivity as reported by others strongly suggests that deactivation by dry surface soils rather than volatility is primarily responsible for the triallate response to incorporation.

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 110-116 ◽  
Author(s):  
W. M. Phillips ◽  
K. C. Feltner

Persistence and movement of 4-amino-3,5,6-trichloropicolinic acid (picloram) were studied in silty clay loam soils located at Hays and Newton, Kansas. At Hays, picloram was applied to a Harney silty clay loam at rates of 2.24 and 3.36 kg/ha in 1963, 1964, 1965, 1966, and 1968 and at Newton to a Goessel (tentative) silty clay loam at rates of 1.12, 2.24, and 3.36 kg/ha in 1966. Fifteen, 20, or 30-cm increments of soil were taken from as deep at 2.4 m below the soil surface and bio-assayed with soybeans(Glycine max(L.) Merr. ‘Clark 63′) in 1968 and 1969. In both soils the highest concentration of phytotoxic residue remained near the soil surface, but differences between the two sites were evident. In the Goessel soil phytotoxic residues were detected only near the surface. In the Harney soil movement was uneven, but residues were detected as deep as 2.4 m below the surface. Soil cracks probably contributed to penetration of small amounts of the herbicide to as much as 2.4 m below the surface. Total picloram remaining in both soils diminished with time.


Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 194-201 ◽  
Author(s):  
L. M. Wax ◽  
E. W. Stoller ◽  
F. W. Slife ◽  
R. N. Andersen

A system for controlling yellow nutsedge(Cyperus esculentusL.) in soybeans [Glycine max(L.) Merr.] which involved preplanting tillage, late planting, herbicides, and cultivation was evaluated in 1969 and 1970. In Illinois on a Drummer silty clay loam,S-ethyl dipropylthiocarbamate (EPTC) andS-ethyl diisobutylthiocarbamate (butylate), incorporated in the soil before planting, gave good and fair control of yellow nutsedge, respectively, but both injured soybeans initially.S-propyl dipropylthiocarbamate (vernolate), also incorporated before planting, controlled yellow nutsedge as well as EPTC did, and resulted in less injury to soybeans. Soybean yields were not reduced by any of the thiocarbamate treatments. Incorporation of 2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide (alachlor) or 2-chloro-N-isopropylacetanilide (propachlor), just before planting, controlled at least 90% of the yellow nutsedge in both years, whereas preemergence applications were only moderately successful and dependent on rainfall. In field microplots, alachlor and vernolate provided only fair control of yellow nutsedge when applied to the soil surface, but they both controlled 95% of the yellow nutsedge when incorporated 7.6 cm. In greenhouse studies on selective control of yellow nutsedge in soybeans, alachlor exhibited a wider margin of safety to soybeans than did vernolate.


Weed Science ◽  
1988 ◽  
Vol 36 (2) ◽  
pp. 243-249 ◽  
Author(s):  
B. B. Petersen ◽  
P. J. Shea ◽  
G. A. Wicks

Laboratory and field research was conducted to determine the influence of winter wheat (Triticum aestivumL.) stubble on weed control and the dissipation of emulsifiable concentrate formulations (EC) of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide], alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], and acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide]; and microencapsulated formulations (ME) of alachlor and acetochlor. EC metolachlor provided better weed control than EC alachlor when applied 28 days before planting sorghum (Sorghum bicolorL.) and similar weed control when applied at 1 or 14 days before planting. This difference was attributed to more rapid EC alachlor dissipation. The order of relative herbicide persistence at 24 C and 33% (w/w) soil moisture in a silty clay loam was ME acetochlor = ME alachlor > EC metolachlor > EC acetochlor = EC alachlor. Acetanilide degradation was affected more by increasing temperature from 15 to 24 C than by increasing soil moisture from 15 to 33%. More herbicide was washed from overwintered than fresh straw in the first 1 cm of simulated rainfall. In the first simulated rainfall event, more herbicide was removed from straw that had been dry than wet at application, but the amount of herbicide remaining on dry and wet straw was similar after four events. Formulation generally did not affect herbicide wash-off.


1985 ◽  
Vol 104 (2) ◽  
pp. 303-307
Author(s):  
P. K. Sharma ◽  
A. K. Sinha ◽  
T. N. Chaudhaby

SummaryUpward flux of water and deep-placed (8–10 cm) P was studied in columns of sandyloam and silty clay loam, with water tables of 60 and 90 cm, each subjected to potential evaporation rates of 2–2 and 7–5 mm/day, for 15 days. An amount of 300 mg P/kg soil, labelled with 20 /tCi 32P/g P, was applied as diammonium hydrogen orthophosphate.Evaporation losses increased with increase in potential evaporation (PE) and decrease in depth to water table in both soils, but the ratio of actual to potential evaporation (AE/PE) decreased with increasing PE, indicating that the evaporative losses in both the soils were mainly controlled by their hydraulic conductive properties. Under no circumstances did AE equal PE. Evaporation, in general, was higher from sandy loam than from silty clay loam.Corresponding to water flux, total upward P flux increased with increasing PE and decreasing depth to water. In the sandy loam, with 2–2 mm PE/day, 21 % of the deepplaced P moved to the soil surface with the 60 cm water table, against 5 % with the 90 cm water table. Under 7–5 mm PE/day, 39% P migrated to the surface with the 60 cm water table, but no 3aP was detected at the surface with the 90 cm water table. In the silty clay loam, however, P movement was much restricted.


2021 ◽  
Author(s):  
T. L. Dirwai ◽  
A. Senzanje ◽  
T. Mabhaudhi

Abstract We developed an empirical soil wetting geometry model for silty clay loam and coarse sand soils under a semi-permeable porous wall line source Moistube Irrigation (MTI) lateral irrigation. The model was developed to simulate vertical and lateral soil water movement using the Buckingham pi (π) theorem. This study was premised on a hypothesis that soil hydraulic properties influence soil water movement under MTI. Two independent, but similar experiments, were conducted to calibrate and validate the model using MTI lateral placed at a depth of 0.2 m below the soil surface in a soil bin with a continuous water supply (150 kPa). Soil water content was measured every 5 minutes for 100 h using MPS-2 sensors. Model calibration showed that soil texture influenced water movement (\(p\) < 0.05) and showed a good fit for wetted widths and depths for both soils ( \(nRMSE\) = 0.5% − 10%; \(NSE \ge\) 0.50; and d-index \(\ge\) 0.50. The percentage bias \(\left(PBIAS\right)\) statistic revealed that the models’ under-estimated wetted depth after 24 h by 21.9% and 3.9% for silty clay loam and sandy soil respectively. Sensitivity analysis revealed an agreeable models’ performance values. This implies the applicability of the model for estimating wetted distances for an MTI lateral placed at 0.2 m. However, further experimentation under varying scenarios for which MTI would be used, including field conditions, is needed to further validate the model and establish robustness. MTI wetting geometry informs placement depth for optimal irrigation water usage.


Author(s):  
Mohammed Aajmi Salman ◽  
Jawad A. Kamal Al-Shibani

Beneficial microorganisms play a key role in the availability of ions minerals in the soil and use Randomized Complete Block Desing ( R.C.B.D ). The objective of this paper to the study effect of the of biofertilizer and miniral treatments on availability of NPK for crop corn zea mays L.Two types of biofertilizer are Bacterial Bacillus subtilis and Fungal Trichoderma harianum. Three levels of potassium fertilizer are (2.9533, 0.4000 and 2.9533). A field experiment in fall season of 2018 Has been conducted in silty clay loam soil. The experimental Results indicated that Bacillus and Trichoderma inoculation separately or together Have made a significant effect to increase in the availability of N P K in the soil compare to other treatments. The grain yield is where (2.9533, 0.4000 and 2.9533) of bacterial and fungal bio-fertilizer and potassium fertilizers respectively as compared to the control.


2021 ◽  
Vol 70 (1) ◽  
pp. 27-40
Author(s):  
Yaung Kwee ◽  
Khin Soe

In this study, two sites from tea and apple growing sites were collected from Pyay village and Nine Mile village, Mindat district, Chin state of West Myanmar under a humid subtropical climate. The results of physicochemical properties of observed soils were neutral pH, favorable moisture, silty clay loam texture, very high content of organic carbon, organic matter and total nitrogen. However, the tea growing soil was very poor in phosphorus and potassium content. Moreover, both soils lack of available potassium. The content of heavy metals in both soils was not varied from each other and followed the order: Fe (iron) > Cu (copper) >Zn (zinc) > Pb (lead) > Cr (chromium) and was below the maximum allowed concentrations (MAC). Therefore, the studied soils are generally favorable for cultivation under the condition of application of phosphorus and potassium fertilizers. However, due to the regular application of fertilizers and pesticides, it is necessary to monitor these soils for PTE levels. Further research is recommended, which must include analyses of the physicochemical properties of soils to a two depths of 0-30 and 30-60 cm, especially for the area where fruit plants are grown. In addition, higher density of soil samples and sub-samples are necessary to produce a reliable dataset that will allow proper statistical analysis.


Author(s):  
Abdulmahdi S.ALansari ◽  
Muhammad M.Yassin ◽  
Mahdi W.Seheib

This study was conducted to evaluation the role of the organic acids in the phosphorus fractions in silty clay loam texture. The laboratoryexperiment was conducted by adding the organic acids (Humic acid ,Citric acid ,Oxalic acid , Malic acid ,Acetic acid and Lactic acid )to the fertilized soil with conc. super phosphate fertilizer with 100 kg h-1 level with concentrations (0,15,30,45 and60)mg L-1,except Humic acid (500,1000,1500 and 2000) mg L-1.The soil was incubated at 30 C for 14,28,42,56 and 70 days period and the keep of field capacity about of incubation period during the daily weight.Amount of available ,mineral ,organic and total phosphorus after each incubated period were measured. The results showed that theaddition of organic acids of Humic acid ,Citric acid ,Oxalic acid and Malic acid were caused to increaseamount of available ,mineral ,organic and constant of total phosphorus in fertilized soil with conc. super phosphate fertilizer and increased its amount with increasing of organic acid concentration and better of Humic acid 2000mg L-1 significanton all the treatments .The results of the study that theaddition of organic acids were caused to increase amount of available and mineral phosphorus with increasing of incubation period and constant amount of total phosphorus and decreasing of organic phosphorus amount and available for only soil and only fertilizer treatment during increasing of incubation period .The organic acids can be arranged according to its ability toincrease the availabilityof the phosphorus as follow :


2008 ◽  
Vol 88 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Hafida Zaher ◽  
Jean Caron

The slaking process after rapid wetting is a key factor controlling soil structural stability in dry soil, and an understanding of the relative importance of the different mechanisms involved in slaking may help in the design of management strategies aimed at maintaining a stable surface soil structure. Slaking has been linked to, among other factors, rapid pressure build-up in aggregate, and previous work has emphasized the role of organic matter to hamper that pressure build-up, possibly due to hydrophobicity, reducing rapid water entry within aggregates and hence the build-up. This study emphasizes this latter aspect linked to slaking. The evolution of the intra-aggregate pressure, the matter lost by slaking and the expelled air after rapid wetting of two soils of different textures (clay loam soil and silty-clay loam soil) amended with different types of paper sludge were studied. Hydrophobicity effects were also studied using a tensio-active solution. The results of these experiments showed that when aggregates were submitted to sudden wetting, those treated with paper sludge had an improved resistance to the destructive action of rapid wetting. The lower pressures measured in the aggregates from the amended soils and having less slaking resulted most likely from slow water entry and reduced swelling. Detailed investigation on the link between hydrophobicity and water entry revealed that the true hydrophobic effect (modification of contact angle) was non-existent for the silty-clay loam and minor for the clay loam. This study, rather, suggests that changes in the water potential at the wetting front following organic matter addition and aggregate immersion most likely depend on pore occlusion and on changes in pore surface roughness. Key words: Aggregate stability, organic matter, slaking, pressure, swelling, wettability


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