EFFECTS OF SOIL PROPERTIES AND AMENDMENTS ON THE AVAILABILITY OF ZINC IN SOILS

1974 ◽  
Vol 54 (4) ◽  
pp. 369-378 ◽  
Author(s):  
A. J. MACLEAN

In a soil incubation experiment with different rates of Zn, the amounts of Zn extracted with 0.005 M DTPA, 1 M MgCl2, and 0.01 M CaCl2 increased with an increase in the organic matter content of a neutral sandy loam soil and with alfalfa added as an organic amendment. Addition of muck and peat increased the amount of Zn exchanged with 1 M MgCl2 but decreased the amount soluble in 0.01 M CaCl2, whereas addition of clay increased the amount of exchangeable Zn but decreased the amounts in the DTPA and 0.01 M CaCl2 extracts. Liming of an acid sandy loam soil (pH 4.9) to about the neutral point reduced the amounts of extractable Zn markedly. A pretreatment of the soils with phosphate almost invariably increased the amounts of extractable Zn. In a corresponding pot experiment, the highest rate of Zn (250 ppm) reduced the yield of corn slightly, prevented the growth of lettuce, and reduced the yield of alfalfa markedly when these crops were grown successively in the acid soil. The concentration of Zn reached levels of 792 ppm in the corn and 702 ppm in the alfalfa. Addition of 50 ppm Zn to the acid soil restricted the growth of lettuce and increased the concentration of Zn to 523 ppm. Despite discrepancies, the concentrations of Zn in the plants as influenced by soil organic matter, organic amendments and liming were usually in accord with the amounts of Zn extracted from the soils. But the P pretreatment tended to decrease the concentration of Zn in corn and lettuce. The mean weight concentrations of Zn in the three species were correlated significantly with the amounts of Zn extracted with 0.005 M DTPA (r = +0.73), 1 M MgCl2 (r = +0.93) and 0.01 M CaCl2 (r = +0.90).

1976 ◽  
Vol 56 (3) ◽  
pp. 129-138 ◽  
Author(s):  
A. J. MACLEAN

The Cd concentration in 10 plant species grown in a neutral surface soil (0.65 ppm Cd) varied from 0.18 ppm in potato tubers to 0.99 ppm in soybean roots on a dry matter basis. Addition of 5 ppm Cd increased the concentrations in the plants markedly and they were particularly high in lettuce (10.36 ppm) and tobacco leaves (11.57 ppm). Cd concentrations tended to be lower in the edible portion (seed, fruit, tubers) than in other plant parts. Added Cd affected yields in only a few instances. But in another experiment, Cd added at a rate of 5 ppm to five soils decreased the yield of lettuce in most instances. In a comparison of results for two similarly managed sandy loam soils, nearly neutral in reaction but differing in organic matter content (2.17 vs. 15.95% organic C), the concentration of Cd was lower in lettuce grown in the soil with the higher amount of organic matter. The Cd content of the lettuce was reduced by liming some of the acid soils. Addition of Cd increased the concentration of Zn in the plants appreciably, but added Zn did not affect Cd uptake. In an incubation experiment comprising five soils, DTPA (diethylenetriamine-pentaacetic acid) extractable Cd decreased with liming of three Cd-treated acid soil samples. In comparisons of two sandy loam soils and of surface and subsoil layers of a sand, extractable Cd increased with higher amounts of soil organic matter.


Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Chris H. Tingle ◽  
David R. Shaw ◽  
Patrick D. Gerard

Laboratory studies were conducted to evaluate14C-flumetsulam mobility in two Mississippi soils of varied texture and organic matter content following delays in irrigation. Mobility was evaluated using packed soil columns, 25 cm deep, under unsaturated–saturated flow conditions. Irrigation timings included 0, 3, and 5 d after flumetsulam application. Flumetsulam mobility (defined as the amount collected in leachate) decreased from 45% to no more than 20% of the applied in the Prentiss sandy loam soil when irrigation was delayed 3 or 5 d. With the Okolona soil, flumetsulam recovery in the leachate was 21, 14, and 6%, respectively when irrigation occurred 0, 3, and 5 d after application. Flumetsulam proved to be mobile when irrigation immediately followed application, with 6 to 45% recovered in the leachate from all soils evaluated. The Prentiss soil retained 6% of the applied flumetsulam in the upper 5 cm and the Okolona soil retained 22% when irrigation immediately followed flumetsulam application. When the irrigation interval was delayed at least 3 d, the Okolona soil retained 40% in the upper 5 cm, whereas the Prentiss soil retained 10%. Flumetsulam mobility was dependent on irrigation timing and soil type.


1973 ◽  
Vol 53 (3) ◽  
pp. 307-314 ◽  
Author(s):  
R. GROVER

The movement of picloram (4-amino-3,5,6-trichloropicolinic acid) was studied in various Canadian Prairie soils, using soil columns. Picloram was readily leached in all soil types. The movement was greatest in the soil with the lowest organic matter and clay contents, and lowest in black soils that are high in soil organic matter content. It was related, in general, to the adsorptive and water-holding capacities of these soils. The extent of leaching of picloram was also related to the total amount of water applied; the greater the amount o¡ water the greater the downward movement. Increasing the intensity of water increments from 0.25 to 2.5 cm enhanced the movement of picloram in the clay soil but had no effect in the sandy loam. There was little or no difference in the movement of picloram when the herbicide was applied at 2.0 or 0.2 kg/ha, Picloram leached to a greater depth when the sandy loam soil was initially dry than wet and the converse was true for the clay soil. Picloram moved readily upwards when the soil columns were subirrigated.


1989 ◽  
Vol 69 (3) ◽  
pp. 489-500 ◽  
Author(s):  
A. N. WEILL ◽  
E. MCKYES ◽  
C. R. DE KIMPE

This study was undertaken to determine the effect of tillage and fertilizer on soil structure in fields under corn production in Quebec. Three types of tillage (moldboard, chisel and zero-till) and two types of fertilizer (manure and inorganic fertilizer) were applied yearly for 6 yr on a clay and a sandy loam soil. Macroaggregation was obtained after dry and wet sieving and microaggregation after sonification. Soil geometric mean diameter and aggregate stability were increased after manure applications and still further by zero-till. The amount of aggregates in each size fraction was affected differently by the fertilizer and tillage treatments. The fraction of organic matter binding the < 250-μm units into > 250-μm units played a greater role in soil aggregation than total soil organic matter content. Key words: Aggregation, manure, organic matter, soil pH, reduced tillage


Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 153-160 ◽  
Author(s):  
M. S. Sharom ◽  
G. R. Stephenson

The adsorption, desorption, and mobility of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] in eight Ontario soils were investigated. The distribution coefficients varied from 0.56 for the least adsorptive Fox sandy loam soil to 31.67 for the most highly adsorptive Leamington muck soil. Most of the adsorbed metribuzin was desorbed from the mineral soils after six aqueous extractions, however substantial amounts of the herbicide remained adsorbed on the muck soils after 10 aqueous extractions. The herbicide was relatively mobile in mineral soils but was immobile in the muck soils. Mobility was inversely correlated with the amount of soil organic matter. Bioassay studies indicated that phytotoxicity of metribuzin also decreased with increasing organic matter content of the soil. Persistence of metribuzin was dependent on microbial degradation. In a field study with Guelph loam, the half-life of metribuzin was approximately 3 months.


Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 478-483 ◽  
Author(s):  
J. B. Weber

Adsorption isotherms were obtained for buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone}, VEL 3510 {1-β,β-dimethoxy-1-methyl-3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]urea}, tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea}, and fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4 (1H)-pyridinone} on soil organic matter (H- and Ca-saturated), Ca-montmorillonite, and Cape Fear sandy loam soil. Prometryn [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine] was included as a reference. The order of adsorption on all adsorbents was fluridone ≥ prometryn > > tebuthiuron ≥ VEL 3510 > buthidazole. Fluridone adsorption on the various adsorbents was: H-organic matter > Ca-montmorillonite > Ca-organic matter > > Cape Fear sandy loam. Tebuthiuron, VEL 3510, and buthidazole adsorption on the various adsorbents was in the order: H-organic matter > Ca-organic matter = Ca-montmorillonite > Cape Fear sandy loam. Adsorption of all herbicides increased with decreasing pH, suggesting that the adsorption mechanism was molecular under neutral pH conditions and ionic under acidic conditions. All of the herbicides were adsorbed in high amounts as protonated species on IR-120-H cation exchange resin and in low amounts as molecular species on IR-400-Cl anion exchange resin. Buthidazole and VEL 3510 were adsorbed in high amounts as anionic species by the IR-400-Cl exchange resin at high pH levels.


1991 ◽  
Vol 5 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Menashe Horowitz ◽  
Clyde L. Elmore

Bentgrass was used to bioassay oxyfluorfen in leaching experiments done in columns of soilless potting media and soils, with herbicide incorporated into the upper 2 to 4 cm. Depth of herbicide leaching increased in order in the following soils: peat and sand (1:1) mix, Stockton clay soil, Yolo fine sandy loam soil, and redwood bark and sand (3:1) mix. Depth of leaching was not related to soil organic matter content. Equilibration experiments showed that peat adsorbed 4 to 5 times more oxyfluorfen than redwood bark. Less leaching was observed in potting mixtures containing peat than bark. Raising the oxyfluorfen dose from 20 to 200 ppmw increased the depth of leaching and concentration of herbicide in the leachate, while a 10-fold increase in water volume had only a limited effect. Twenty ppmw of oxyfluorfen incorporated in the top of a peat-containing potting medium has a low risk of leaching out of the container.


2017 ◽  
Vol 68 (3) ◽  
pp. 305-316 ◽  
Author(s):  
A. E. Johnston ◽  
P. R. Poulton ◽  
K. Coleman ◽  
A. J. Macdonald ◽  
R. P. White

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