scholarly journals Evaluation of leaching potential of tebuthiuron using bioindicator plants

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Antonio Carlos da Silva Junior ◽  
Clebson Gomes Gonçalves ◽  
Juliana Roberta Gobi Queiroz ◽  
Dagoberto Martins

ABSTRACT: The last destination of most herbicides used in agricultural systems is the soil. This is a dynamic interaction; herbicides can remain in the soil solution or be carried through the soil profile, reaching the water table. The objective of this work was to evaluate the leaching potential of the tebuthiuron herbicide using bioindicator plants grown in an Oxisol of sandy loam texture and in an Entisol of clay texture, after the occurrence of natural rainfall events. A complete randomized experimental design was used, in a 3×8 factorial arrangement, with four replications. The treatments consisted of three accumulated natural rainfall depths (30-40, 60-80, and 100-120 mm) and eight soil profile layers (0-3, 3-6, 6-9, 9-12, 12-15, 15-20, 20-25, and 25-30 cm). Soil samples were collected after the tebuthiuron herbicide application - 750 for clayey soil, and 600 g ha-1 for the sandy loam soil -and the rainfall events. PVC pipes with length of 30 cm and diameter of 15 cm were introduced into the soil profile for sampling. The pipes with soil columns were carefully removed by digging around them, to maintain the soil original integrity during collection and, subsequently, cut longitudinally for sowing the bioindicator species - cucumber (Cucumis sativus L.), and lettuce (Lactuca sativa L.). Then, the phytotoxicity in the bioindicator plants grown in these soils were evaluated at 5, 7, 10, and 12 days after sowing, using a grading scale of 0 to 100%. The mobility of the tebuthiuron herbicide was low in both soils, regardless of the rainfall depth, and the cucumber was the most suitable plant species to use as a bioindicator.

Weed Science ◽  
1989 ◽  
Vol 37 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Howard L. Morton ◽  
Thomas N. Johnsen ◽  
J. Roger Simanton

Tebuthiuron was applied at 1 kg ai/ha to wet and dry Hathaway gravelly, sandy loam soil in the spring and fall to determine the amount of tebuthiuron removed in runoff water and the depth to which it would move within the soil profile by simulated rainfall. When pellets containing 20% ai of tebuthiuron were broadcast onto dry soil in the spring, the first simulated rainfall event, 37 mm, removed 5% of the applied tebuthiuron in runoff water and sediment. The second and third simulated rainfall events, 22 and 21 mm, respectively, removed an additional 2%. When tebuthiuron was applied to wet soil in the spring, the initial simulated rainfall events, totaling 42 mm, removed 15% of the tebuthiuron. When tebuthiuron was applied to wet soil in the fall, the initial rainfall events, totaling 40 mm, removed a total of 48% of the tebuthiuron in runoff water and sediment. No significant differences were found in the total amount of tebuthiuron within the soil profile after application to dry and wet soils. More than half of the tebuthiuron had moved into the surface 7 cm 1 day after application. Tebuthiuron was not detected below 90 cm after 165 mm of simulated rainfall and 270 mm of natural rainfall.


Author(s):  
Ana P. da Silva ◽  
Ricardo F. Marques ◽  
Antônio C. da Silva Junior ◽  
Sidnei R. de Marchi ◽  
Dagoberto Martins

ABSTRACT Information about the impact of herbicides in the soil based on the growth of bioindicator species is extremely useful in developing crop management strategies. Therefore, this study aims to evaluate the leaching potential of the herbicide S-metolachlor under different natural precipitations in medium-textured Oxisol using bioindicator plants. A completely randomized experimental design was adopted, with four replicates and treatments arranged in a 3 × 8 factorial scheme [three indexes of precipitation occurred in the environment before the collection of the samples (50, 91, and 131 mm) and eight depths in the soil profile (0-0.03; 0.03-0.06; 0.06-0.09; 0.09-0.12; 0.12-0.15; 0.15-0.20; 0.20-0.25; 0.25-0.30 m)]. PVC columns were used, maintaining the original soil integrity during sampling after accumulating the stipulated natural precipitation. Longitudinal sections separated the columns to sow the bioindicator species (cucumber, lettuce, Alexander grass, and sorghum). The phytotoxicity symptoms of bioindicator plants were evaluated, adopting a phytotoxicity visual scale between 0 and 100%, at 5, 7, 9, and 11 days after seeding. The responses of the bioindicator species to the residual effect of the herbicide S-metolachlor were variable and depended on the rainfall level. Generally, in a medium-textured Oxisol, the higher values of concentration of S-metolachlor occurs in depths ranging between 0 and 0.06 m. The maximum leaching depth detected was 0.12-0.15 m with 131 mm of precipitation. Cucumber was the most sensitive species to the presence of S-metolachlor in an Oxisol of medium-texture since it presents symptoms of phytotoxicity at higher depths.


2019 ◽  
Vol 99 (1) ◽  
pp. 36-45 ◽  
Author(s):  
J.J. Miller ◽  
M.L. Owen ◽  
X. Hao ◽  
C.F. Drury ◽  
D.S. Chanasyk

Limited research exists on legacy effects of land application of feedlot manure on accumulation, redistribution, and leaching potential of water-extractable organic carbon (WEOC) in soil profiles. We sampled a clay loam soil at six depths (0–1.50 m) 2 yr after the last application (2014) of 17 continuous annual manure applications (since 1998). The amendment treatments were stockpiled (SM) or composted (CM) feedlot manure containing straw (ST) or wood-chip (WD) bedding at three application rates (13, 39, and 77 Mg ha−1dry basis). There was also an unamended control (CON) and inorganic fertilizer (IN) treatment. The soil samples were analyzed for concentrations of WEOC. The total mass or accumulation of WEOC in the soil profile was greater (P ≤ 0.05) by 1.2–3.3 times for the CM-ST-77 treatment than 12 of 14 other treatments, and it was significantly greater for amended than CON or IN treatments. The total WEOC mass was 14%–20% greater for CM-ST than CM-WD, SM-ST, and SM-WD treatments, and it was 16%–22% greater for CM than SM at the 39 and 77 Mg ha−1rates. The 77 Mg ha−1rate of the four manure type-bedding treatments had the significantly greatest (by 37%–527%) concentrations of WEOC at the six depths compared with other treatments, suggesting greater redistribution and leaching potential. Significant manure effects occurred on soil WEOC 2 yr after the manure was last applied following 17 continuous applications, and it indicated an increased risk of leaching potential at the higher application rate.


Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 459-464 ◽  
Author(s):  
P. A. Abbasi ◽  
G. Lazarovits

A formulation of phosphonate (AG3) was tested as a seed treatment for the control of Pythium damping-off of cucumber (Cucumis sativus L.) plants under controlled environment and field conditions. Cucumber seed were treated by soaking for 10 min in phosphonate solution. They were then planted into peat-based mix or sandy-loam soil mixed with Pythium aphanidermatum or P. ultimum inoculum or into muck soil naturally infested with P. irregulare, P. ultimum, and other Pythium spp. Under growth-room conditions, phosphonate seed treatment provided more than 80% control of damping-off in all infested substrates tested. Effective disease control was obtained even when treated seed were stored for 5 weeks and up to 18 months prior to planting. In microplots containing naturally infested muck soil, phosphonate seed treatment decreased the percentage of diseased cucumber plants and increased total fresh weights compared with untreated seed and phosphonate post-planting drench. In field-plot tests 6 weeks after planting treated seed in Pythium-infested muck soil, cucumber stands were 63% compared with 18% in the control, which had no phosphonate exposure, and 53% in the post-planting drench. Tests for potential phytotoxicity in the greenhouse showed that radish and bok choy germination was reduced by phosphonate treatment but corn, cucumber, soybean, sugar beet, tomato, and wheat were not affected. Phosphonate seed treatment is a cost-effective way of protecting cucumber plants from Pythium damping-off.


2007 ◽  
Vol 56 (2) ◽  
pp. 169-178 ◽  
Author(s):  
M. Kogan ◽  
S. Rojas ◽  
P. Gómez ◽  
F. Suárez ◽  
J.F. Muñoz ◽  
...  

A field study was performed to evaluate the accuracy of six pesticide screening leaching indexes for herbicide movement. Adsorption, dissipation and soil movement were studied in a vineyard in a sandy loam soil during 2005 season. Simazine, diuron, pendimethalin, oxyfluorfen and flumioxazin were applied to bare soil at rates commonly used, and their soil concentrations throughout soil profile were determined at 0, 10, 20, 40 and 90 days after application (DAA). Herbicides were subjected to two pluviometric regimens, natural field condition and modified conditions (plus natural rainfall 180 mm). Leaching indexes utilized were: Briggs's Rf, Hamaker's Rf, LEACH, LPI, GUS and LIX. Simazine reached 120 cm, diuron 90 cm, flumioxazin 30 cm soil depth respectively. Pendimethalin and oxyfluorfen were retained up to 5 cm. None of the herbicides leaching was affected by rainfall regimen. Only flumioxazin field dissipation was clearly affected by pluviometric condition. The best representation of the herbicide soil depth movement and leaching below 15 cm soil depth were: Hamaker's Rf < Briggs's Rf<GUS<LPI,<LEACH<LIX. Field results showed a good correlation between herbicides Kd and their soil depth movement and mass leached below 15 cm soil depth.


2019 ◽  
Vol 37 (4) ◽  
pp. 402-408
Author(s):  
Luanna C Monteiro ◽  
Celso Aita ◽  
Janquieli Schirmann ◽  
Stefen B Pujol ◽  
Ana Paula Mezzalira ◽  
...  

ABSTRACT This study was developed to evaluate nitrogen (N) supply to arugula from composts produced by automated composting of pig slurry (PS). During the composting process, retorted oil shale (ROS) and dicyandiamide (DCD) were added to PS to mitigate gaseous N losses. The study was developed in a greenhouse where four treatments were evaluated, three with compost addition (PS compost, PS compost + ROS, and PS compost + ROS + DCD) and one without compost (control) in two contrasting soils (clayey and sandy-loam). The best result was obtained with the compost without additives (PS compost), which increased the arugula dry matter yield 2.2 times in clayey soil and 6.1 times in sandy-loam soil compared to the control treatment. The presence of ROS in composts reduced arugula dry matter yield in 27% in clayey soil and 35% in sandy-loam, while DCD did not affect arugula dry matter yield. The results of this study show that the addition of ROS to PS during composting reduces N supply to arugula, both in the immediate (first cut) and residual effect (second cut).


2020 ◽  
Vol 11 ◽  
pp. e3398
Author(s):  
Robson de Oliveira Galvão ◽  
Sebastião Elviro de Araújo Neto ◽  
Nilciléia Mendes da Silva ◽  
Luís Gustavo de Souza e Souza ◽  
Thays Lemos Uchôa ◽  
...  

This research aimed to evaluate the effect of doses of organic compost on the yield and economic profitability of organic yellow passion fruit grown in sandy-loam and clay-loam soils. Two experiments were installed in the field, in different soil types and municipalities in the state of Acre. The experimental design was in randomized blocks with five treatments, four replications, and four plants per experimental unit. The treatments consisted of adding the compost as a replacement for 1/3 of the volume of cylindrical planting holes with 40 cm, 80 cm, 120 cm, 160 cm, and 200 cm, corresponding to the addition of 6.3; 25.1; 56.5; 100.4, and 156.9 liters per planting hole, respectively. The mean fruit mass and the yield of the yellow passion fruit were higher in sandy-loam soil. The total revenue was R$ 4,311.6 ha-1 in the clayey soil and R$ 5,841.9 ha-1 in the sandy soil. The total cost was higher in the clayey soil than in sandy soil. Both soils responded in quadratic function with an increase in the cost as the volume of organic compost was increased, ranging from R$ 12,736.00 ha-1 with 6.3 liters of compost per hole up to R$ 26,249.63 ha-1 with 156.9 liters of compost per hole. Net income was negative for all compost volumes in both types of soil, responding linearly, with a reduction in revenue of R$ 80.82 ha-1 with the addition of each liter of compost in the pit due to the low yield caused by period long drought.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2012
Author(s):  
Yu-Lin Kuo ◽  
Chia-Hisng Lee ◽  
Shih-Hao Jien

Background: Loss of nutrients and organic carbon (OC) through leaching or erosion may degrade soil and water quality, which in turn could lead to food insecurity. Adding biochar to soil can effectively improve soil stability, therefore, evaluating the effects of biochar on OC and nutrient retention and leaching is critical. Methods: We conducted a 42-day column leaching experiment by using sandy loam soil samples mixed with 2% of biochar pyrolyzed from Honduran mahogany (Swietenia macrophylla) wood sawdust at 300 °C (WB300) and 600 °C (WB600) and a control sample. Leaching was achieved by flushing the soil column on day 4 and every week during the 42-day experiment and adding a water volume for each flushing equivalent to the field water capacity. Results: Biochar application increased the final soil pH and OC, NH4+-N, NO3−-N, available P concentrations but not exchangeable K concentrations. In particular, WB600 exhibited superior performance in alleviating soil acidification; WB300 engendered high NO3−-N concentrations. Biochar application effectively retained water in soil and inhibited the leaching of the aforementioned nutrients and dissolved OC. WB300 reduced NH4+-N and K leaching by 30%, and WB600 reduced P leaching by 68%. Conclusions: Biochar application can improve nutrient retention and reduce the leaching potential of soils and connected water bodies.


Soil Research ◽  
1975 ◽  
Vol 13 (2) ◽  
pp. 133 ◽  
Author(s):  
KK Watson ◽  
SJ Lees

The significance of the soil profile and its accompanying water status in deterministic catchment models is discussed in relation to the current use of the soil-store concept. An alternative numerical approach is described in which the movement of water into and through the soil profile (together with the determination of runoff volumes) is continuously monitored during any pattern of rainfall and non-rainfall events. A significant component in the approach is the use of a comprehensive domain-type hysteresis model for the analysis of infiltration-redistribution sequences. The simulation is illustrated by using a rainfall hyetograph of 7 h duration (including one non-rainfall period of 1 h) as the flux input into a homogeneous profile of a sandy loam of uniform initial water content. The time-dependent relationships of rate of surface flux, depression storage and runoff volume are calculated for the duration of the hyetograph period. Profiles of water content are also presented.


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