Adsorption of Chlorimuron-Ethyl on Two Typical Chinese Soils as Affected by Cd

2011 ◽  
Vol 281 ◽  
pp. 296-300
Author(s):  
Xiang Rong Qu
Keyword(s):  
Environmental Risk ◽  
Equilibrium Solution ◽  
Soil Surface ◽  
Black Soil ◽  
Solution Ph ◽  
Batch Equilibration ◽  
Chlorimuron Ethyl

Coexistence of chlorimuron-ethyl and Cd is very common in Chinese soils. Adsorption of chlorimuron-ethyl and Cd on soils strongly affects their mobility. This study was conducted to investigate the effect of Cd on the adsorption of chlorimuron-ethyl on two typical Chinese soils, brown earth (BE) and black soil (BS). Batch equilibration methods were applied. The presence of Cd enhanced the adsorption of chlorimuron-ethyl on BE and BS, which resulted from the decrease of equilibrium solution pH caused by Cd2+ exchange with H+ ions of soil surface. Besides that, chlorimuron-ethyl adsorption possibly takes place on sites where Cd was previously adsorbed and the adsorbed Cd acted as a bridge between the soil and chlorimuron-ethyl. Such results suggested that Cd in field may decrease the mobility and bioavailability of chlorimuron-ethyl and correspondingly decrease its environmental risk.

The Environmental Risk Assessment of Herbicide Anilofos on Various Chinese Cultivated Soils

2011 ◽  
Vol 356-360 ◽  
pp. 1786-1789 ◽  
Author(s):  
Yi Hua Liu ◽  
Fu Bin Tang ◽  
Guo Nian Zhu
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Environmental Fate ◽  
Glass Plate ◽  
Soil Surface ◽  
Soil Samples ◽  
Adsorption Coefficient ◽  
Leaching Behavior ◽  
First Order ◽  
First Order Kinetics

Anilofos is the organophosphorus herbicide widely used in China. However, little is known on the processes governing the environmental fate of anilofos in soils and its environmental risk for groundwater. Several environmental fate studies were performed concerning the degradation, sorption, photolysis and mobility of anilofos in soils. The degradation of anilofos in three Chinese soil samples followed first-order kinetics, with half-lives between 64.2 d-161.2 d. The adsorption coefficient (KF) values for the three soils were 10.67 (loam), 31.29 (clay) and 11.63 (sand). No notable photolysis of anilofos occurred on soil surface. Leaching tests, performed in manually packed soil glass-plate, indicated that anilofos moved very slowly on the three types of soil thin layer. Thus, the leaching behavior of anilofos coincided well with the results of the batch sorption and degradation experiments. The data generated from this study could be helpful for risk assessment studies of the pesticide in the environment.

Exchangeable Cations and Picloram Sorption by Soil and Model Adsorbents

Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 257-262 ◽  
Author(s):  
J. S. Arnold ◽  
W. J. Farmer
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Equilibrium Solution ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Cation Exchange Resin ◽  
Adsorptive Capacity ◽  
Solution Ph ◽  
Exchange Complex ◽  
Polyvalent Cations

The adsorption of picloram (4-amino-3,5,6-trichloropicolinic acid) was determined on an Aiken silt loam, on three cation exchange resins and on a single anion exchange resin. Adsorption data were evaluated using parameters in the Freundlich equation and their dependance upon cationic composition of the exchange complex, the ionic composition of the equilibrium solution, and the equilibrium solution pH. For the Aiken soil saturated with metallic cations the order of decreasing picloram adsorptive capacity was Fe+3= Cu+2> Al+3> Zn+2> Ca+2> native soil. Increases in adsorption compared to the native Aiken soil could be explained on the basis of decreases in the equilibrium solution pH except for Fe+3, Zn+2, and especially the Cu+2treatments. The adsorptive capacity of the Aiken soil was altered by the addition of several salts simulating addition of fertilizer salts. The Cu+2and Zn+2salts were the only treatments showing increased adsorption which could not be explained readily by pH changes. KH2PO4and NH2CONH2(urea) reduced picloram adsorption. Dowex 50-1 × 4, a strongly acidic cation exchange resin, showed increased picloram adsorptive capacity in the order Cu+2> Al+3> Ca+2> Zn+2= H+. Cellex CM, a weakly acidic cellulose exchanger had increased adsorptive capacities in the order of Cu+2> Ca+2> Al+3> Na+> Fe+3> Zn+2. Picloram adsorption by an anion exchange resin at pH 6.1 was nearly 100%. These results suggest that complex formation of picloram with polyvalent cations on the exchange complex is likely especially for Cu+2and to a lesser extent Fe+3and Zn+2. In soils such complex reactions would most probably involve organic matter, polyvalent cations, and picloram. The formation of chelate ring species is proposed.

Redvine (Brunnichia ovata) Germination and Emergence

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 33-36 ◽  
Author(s):  
David R. Shaw ◽  
Robert E. Mack ◽  
Clyde A. Smith
Keyword(s):  
Osmotic Stress ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Optimum Temperature ◽  
Solution Ph ◽  
Soil Medium ◽  
Petri Dishes

Optimum temperature for germination and emergence of redvine seed in either petri dishes or soil was 35 C. Reductions in germination and emergence occurred at constant temperatures above or below this temperature. No germination or emergence occurred at temperatures above 40 or below 25 C. Germination in petri dishes first occurred on day 8, and emergence was first observed 12 days after planting in a soil medium. Maximum redvine seedling emergence of 74% occurred in soil when seed were planted 0.5 cm deep, with decreases in emergence noted at depths below 5 cm. No emergence occurred over the 35-day period evalμated when redvine seed were planted on the soil surface or at a depth of 10 cm in soil. Redvine germination was not affected by solution pH, whereas germination did not occur when osmotic stress of as little as −200 kPa was applied to seed.

scholarly journals Transformation of properties of chornozems and their resistance to anthropogenic pressure

2013 ◽  
pp. 8-16
Author(s):  
Sviatoslav Baluk ◽  
Liudmyla Vorotyntseva
Keyword(s):  
Land Use ◽  
Soil Properties ◽  
Environmental Risk ◽  
Black Soil ◽  
Sustainable Land Use ◽  
Soil Stability ◽  
Anthropogenic Pressure ◽  
Soil Humus ◽  
Agricultural Use ◽  
Definition Of

The directions of the transformation of the properties of chernozems under the influence of agricultural use and irrigation are shown. For balanced and sustainable land use is required anthropogenic load on the soil based on the definition of acceptable environmental risk of degradation, taking into account the soil stability to anthropogenic pressure. Keywords: soil properties, soil, humus, irrigation, soil stability, black soil.

Pitted morningglory (Ipomoea lacunosa) germination and emergence as affected by environmental factors and seeding depth

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 910-916 ◽  
Author(s):  
Marcos J. Oliveira ◽  
Jason K. Norsworthy
Keyword(s):  
Red Light ◽  
Soil Surface ◽  
Moisture Stress ◽  
Hypocotyl Elongation ◽  
Burial Depth ◽  
Hypocotyl Length ◽  
Solution Ph ◽  
Wide Range ◽  
Pitted Morningglory ◽  
Ph Range

Laboratory and greenhouse experiments were conducted to determine the effect of light, temperature, solution pH, solution osmotic potential, and oxygen concentration on pitted morningglory germination and radicle plus hypocotyl elongation, and seeding depth on its subsequent emergence. Daily exposure of seed to natural light resulted in lower germination than in darkness, whereas germination was not influenced by brief exposure to red or far-red light. Germination occurred over a wide range of constant temperatures, from 7.5 to 52.5 C, with optimum germination between 20 and 25 C. Germination occurred at solution pH range of 3 to 10 and was optimal from pH 6 to 8. Radicle plus hypocotyl elongation was influenced by the interaction of temperature and solution pH. A combination of acidic medium (pH 6) and high temperature (30 C) resulted in the greatest radicle plus hypocotyl length of 7.6 cm after a 7-d incubation. Germination and radicle plus hypocotyl elongation, averaged over the 15 and 30 C temperature, decreased with increasing moisture stress, with less than 3% normalized germination at −1.0 MPa. Germination was 29, 40, and 51% at 2, 10, and 20% oxygen, respectively, averaged over 15 and 30 C. Germination of seed lying on the soil surface covered with filter paper or without any cover was similar, averaging 64%. Normalized emergence, relative to germination on the soil surface, decreased with increasing burial depth to 4% emergence at 10 cm, with a mean emergence depth of 4.1 cm, averaged across two soil types.

Wild Poinsettia (Euphorbia heterophylla) Germination and Emergence

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 103-106 ◽  
Author(s):  
Barry J. Brecke
Keyword(s):  
Osmotic Potential ◽  
Soil Surface ◽  
Solution Ph ◽  
Wide Range

Wild poinsettia germination was at least 95% when exposed to solution pH of 2.5 to 10 or solution osmotic potential of up to −0.8 MPa. No germination was observed at pH 12 or osmotic potential of −1.5 MPa. Light was not required for germination. Seed germinated at temperatures ranging from 20 to 40 C with maximum germination of 97% at 35 C. Wild poinsettia had the highest emergence (80%) from seed placed 2 to 4 cm below the soil surface, while 20% of the seed planted at 14 cm emerged. Wild poinsettia germinated over a wide range of conditions, which explains why it is becoming an increasingly serious problem.

Seed Germination Ecology of Catchweed Bedstraw (Galium aparine)

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 634-641 ◽  
Author(s):  
Hongchun Wang ◽  
Bing Zhang ◽  
Liyao Dong ◽  
Yuanlai Lou
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Continuous Darkness ◽  
Solution Ph ◽  
Galium Aparine ◽  
Ph Range

The influence of temperature, light, solution pH, water stress, salt stress, and burial depth on seed germination and seedling emergence of catchweed bedstraw and the sensitivity of that weed to commonly available herbicides in China were studied in laboratory and greenhouse. Germination occurred at day/night temperatures from 5/0 C to 30/25 C, with optimum germination at 15/10 C. Catchweed bedstraw germinated equally well under a 12-h photoperiod and continuous darkness; however, a 24-h photoperiod inhibited seed germination. Catchweed bedstraw seed is moderately sensitive to osmotic potential and salt stress, with 15 and 3% germination rates at an osmotic potential of −0.5 Mpa and salinity level of 120 mM, respectively. Maximum seed germination was observed in near neutral pH; germination was greater than 80% over a broad pH range from 5 to 8. Seedling emergence of the seeds buried at a depth of 1 cm was higher (74%) than those placed on the soil surface (20%), but declined with burial depth increasing. Few (10%) seedlings emerged when seeds were placed at a depth of 5 cm. Bensulfuron-methyl, and ethametsulfuron-methyl applied PRE and tribenuron-methyl, fluroxypyr, and florasulam applied POST can be used to provide greater than 80% control of catchweed bedstraw. The results of this study have contributed to more complete understanding of the germination and emergence of catchweed bedstraw.

PEAT AND COMMERCIAL FERTILIZERS AS AMENDMENTS FOR GRAY WOODED SOILS

1942 ◽  
Vol 20c (2) ◽  
pp. 68-84
Author(s):  
R. E. Carlyle ◽  
J. D. Newton
Keyword(s):  
Ammonium Sulphate ◽  
Crop Yields ◽  
Ammonium Phosphate ◽  
Soil Surface ◽  
Black Soil ◽  
Plate Count ◽  
Ratio Method ◽  
Wheat Crop ◽  
Triple Superphosphate ◽  
Surface Peat

The nitrates in pot cultures of gray wooded soil were generally affected by the various amendments as follows: increased by applications of neutral or acid subsurface peat and not depressed by neutral or acid surface peat; increased by ammonium phosphate alone and in combination with the surface and subsurface peats, and by ammonium sulphate in combination with the subsurface peats, but slightly depressed by triple superphosphate in combination with the subsurface peats.The wheat crop yields in pot cultures of gray wooded soil were generally affected by the various amendments as follows: increased somewhat by peat alone, and especially by subsurface peat; increased substantially by ammonium phosphate alone, but increased to a greater extent in all three series by a combination of ammonium phosphate and subsurface peat; increased substantially by ammonium sulphate and subsurface peat, but not by triple superphosphate and peat.The plate counts of bacteria in treated cultures of gray wooded soil increased for two to four months, and then decreased. The ammonium phosphate plus subsurface peat treatment gave the highest counts, the ammonium phosphate plus surface peat the second highest, and the ammonium sulphate plus subsurface peat the third highest. The differences between the effects of triple superphosphate plus subsurface peat, ammonium phosphate, surface peat, and subsurface peat, were small. The control gave only a small increase during the course of the experiment.The ratio method showed that there are very large numbers of bacteria in gray wooded soil. Instead of ranging from about 500,000 to about 8,000,000 per gm. of soil as with the plate count method, the numbers varied from about 200,000,000 to 2,000,000,000. The numbers reached a maximum after three months' incubation. The ammonium phosphate plus subsurface peat treatment again gave the highest average number, and the succeeding order was also about the same as in the case of the plate counts.When mixed with gray wooded soil, surface peat, though highly carbonaceous, did not cause any significant decrease in nitrate at first, and produced some increase later. Straw caused some decrease at first, but the later recovery counterbalanced this loss. Cotton caused a decrease to practically none for about three months, and even when combined with ammonium phosphate caused some decrease. Ammonium phosphate alone and in combination with straw and surface peat produced large increases in nitrate. In a duplicate experiment with black soil the trends were similar, but the nitrate was not reduced to the same extent by straw and cotton, and when ammonium phosphate was added with the organic matter, nitrate was not reduced by peat, straw, or cotton.

Coffee senna (Cassia occidentalis) germination and emergence is affected by environmental factors and seeding depth

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 657-662 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Marcos J. Oliveira
Keyword(s):  
Weed Management ◽  
Sandy Loam ◽  
Management Strategies ◽  
Red Light ◽  
Soil Surface ◽  
Moisture Stress ◽  
Integrated Weed Management ◽  
Temperature Threshold ◽  
Burial Depth ◽  
Solution Ph

Laboratory and greenhouse experiments were conducted to determine the effect of light, temperature, moisture stress, solution pH, and burial depth on coffee senna germination and emergence. Seeds germinated equally with or without light, and pretreatment with red or far-red light did not affect germination. Optimum temperature for germination was 25 C, and a high germination percentage (> 70%) occurred from 12.5 to 30 C. The low temperature threshold for germination was between 10 and 12.5 C, whereas the upper threshold was near 45 C. Coffee senna germination in response to moisture stress and solution pH differed at 15 and 30 C. At −0.4 MPa, no germination occurred at 15 C, whereas 15% germination occurred at 30 C. Optimum germination was at pH 6, but further increases in pH had a more negative effect on germination at 15 C than at 30 C. Coffee senna germination ranged from 9 to 12% at pH 3, but was 0% at pH 10, which indicates that coffee senna germination was more tolerant of acidic than basic solutions. Depth-mediated emergence inhibition was sigmoidal, with greatest emergence on the soil surface. Emergence from 2- to 10-cm depths reached 95% of the total emergence 1 to 3 d earlier in a sandy loam than in a sand soil. Mean emergence depth was 1.7 cm in the sand and 2.4 cm in the sandy loam soil. Knowledge gained from this research will be instrumental in developing a better understanding of the requirements for coffee senna germination and emergence, allowing further development and improvement of integrated weed management strategies specific to this troublesome weed.

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