Adsorption and Diffusion of Dinitroaniline Herbicides in Soils

Weed Science ◽  
1979 ◽  
Vol 27 (4) ◽  
pp. 450-455 ◽  
Author(s):  
G. L. Jacques ◽  
R. G. Harvey
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Water Content ◽  
Soil Water ◽  
The Other ◽  
Silt Loam ◽  
Relative Mobility ◽  
Water Saturated ◽  
And Diffusion ◽  
Dinitroaniline Herbicides

Adsorption of benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine), dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine), fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)aniline], oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide), profluralin [N-(cyclopropylmethyl)-α,α,α-tri-fluoro-2,6-dinitro-N-propyl-p-toluidine], and trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) was studied in 10 Wisconsin soils. Ratios of the quantity of each herbicide adsorbed and quantities remaining in the soil solution at equilibrium (Kd value) on a Piano silt loam (Typic Argiudoll fine-silty, mixed, mesic) remained relatively constant over a range of concentrations. Herbicide adsorption by the soils was related more closely to soil organic matter than to the other soil chemical and physical properties. Diffusion of the herbicides in Piano silt loam was affected by soil water. Diffusion of trifluralin, profluralin and benefin decreased as soil water increased. Diffusion of dinitramine and fluchloralin did not change significantly with change in water content. Diffusion of oryzalin increased at the highest soil water content. None of the herbicides moved more than 10 mm in the soil during a 17-day period. In unsaturated Piano silt loam, relative mobility of the herbicides was trifluralin ≥benefin>profluralin>fluchloralin>dinitramine≥oryzalin. Oryzalin reached highest mobility in water-saturated soil.

A numerical approach for understanding the main parameters and processes influencing the soil organic matter decay in wildfire events

2020 ◽  
Author(s):  
Sebastián A. Aedo ◽  
Carlos A. Bonilla
Keyword(s):  
Thermal Conductivity ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
High Temperatures ◽  
Pore Radius ◽  
Radiative Energy ◽  
Soil Response

<p>High temperatures reached at topsoil during wildfires can induce changes in physical, chemical, and biological soil properties. In the end, these changes are related to the loss of soil organic matter (SOM) and control the post-fire soil management decision. Therefore, the objectives of this study were: (1) to develop a numerical model to predict the SOM decay during wildfires, and (2) to study which are the main parameters that control the soil response. The model couples the energy balance for soil heating, and the species conservation for water and SOM using high temperature-induced vaporization and combustion kinetics. Fluid flow was neglected; however, radiative energy conducted through pores was included as a function of the volumetric pore radius. The soil thermal evolution showed values of r<sup>2</sup>>0.92 when the radiative term in the thermal conductivity was neglected, and r<sup>2</sup>>0.98 when the volumetric pore radius was adjusted. The results showed that the main parameters that control the soil response were soil texture, soil water content, volumetric pore radius, and oxygen availability. Also, soil response depends on the surface temperature and exposure time. Soil water content enhances the thermal properties and determines the amount of heat consumed during vaporization because of the high enthalpy of this endothermic reaction. On the other hand, neglecting oxygen flux leads to restricted oxidation, limiting the SOM decay. In terms of texture, silty soils showed the lower soil response, clay and loamy soils an intermediate response, and sandy soils had a higher response. Also, the volumetric pore radius enhances the soil thermal conductivity at high temperatures, leading to higher temperatures near the soil surface. These results suggest that the normalized SOM decay does not depend on the initial SOM content.</p>

Quantity and biodegradability of dissolved organic matter released from sequentially leached soils, as influenced by the extent of soil drying prior to rewetting

Soil Research ◽  
2019 ◽  
Vol 57 (4) ◽  
pp. 374 ◽  
Author(s):  
Tihana Vujinović ◽  
Timothy J. Clough ◽  
Denis Curtin ◽  
Esther D. Meenken ◽  
Niklas J. Lehto ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Pore Volume ◽  
Arable Soil ◽  
The Other ◽  
Grassland Soil ◽  
Soil C

Soil rewetting can induce a flush of organic matter mineralisation, but the factors underpinning this mineralisation response are poorly understood. We investigated the effects of antecedent soil water content, before rewetting, on the quantity, quality and biodegradability of dissolved organic matter present in the leachate pore volumes from a soil under two different management histories: arable and grassland. Soils were collected at field capacity (FC) and dried to give four soil gravimetric water contents (θg): 22% (not dried, left at FC), 15%, 8% and <2% (air dry, AD). Soils were repacked to the same bulk density (1.1 g cm–3) and each core was sequentially leached, with four pore volumes collected. The total amount of dissolved organic carbon (DOC) leached increased (P < 0.001) only in the soils that had been air-dried before rewetting (3.8 and 5.3 mg g–1 soil C, for arable and grassland respectively), while among the other θg treatments differences were relatively small (1.6–2.4 mg g–1 soil C). The pre-rewetting θg treatment affected the DOC content of the pore volume leached (P < 0.001): in the grassland soil, the DOC of the AD treatment was consistently twice as high as the other θg treatments, but this trend was not as consistent in the arable soil. For all θg treatments and both soils, specific ultraviolet absorbance at 254 nm increased as leaching progressed. Biodegradability, expressed as cumulative CO2 produced per unit of DOC in leachates, was significantly lower in the first pore volume of all treatments in the grassland soil and increased with sequential leaching. In the arable soil, differences were small or insignificant across the pore volumes leached, but were large and inconsistent across the θg treatments. These findings improve our understanding of how antecedent soil water content affects the quantity and quality of dissolved organic matter released when soils are rewetted, and the potential for soil carbon losses.

Efficacy of downy brome herbicides as influenced by soil properties

1994 ◽  
Vol 74 (1) ◽  
pp. 177-183 ◽  
Author(s):  
R. E. Blackshaw ◽  
J. R. Moyer ◽  
G. C. Kozub
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Bromus Tectorum ◽  
Edaphic Factors ◽  
Downy Brome ◽  
Winter Cereals ◽  
Highly Correlated

Controlled environment experiments were conducted to determine the effect of various edaphic factors on the efficacy of metribuzin, BAY SMY 1500, cinmethylin, and napropamide to control downy brome (Bromus tectorum L.). Experiment 1 determined the effects of soil organic matter, pH and texture and experiment 2 determined the effect of soil water contents ranging from −0.03 to −1.5 MPa on herbicide efficacy on downy brome. Metribuzin, BAY SMY 1500, cinmethylin, and napropamide efficacy on downy brome was highly correlated with soil organic matter and soil water content. Phytotoxicity of these herbicides was decreased up to two- to threefold as organic matter increased and soil water content decreased. Metribuzin and BAY SMY 1500 efficacy on downy brome increased as soil pH increased. Cinmethylin was more efficacious in sandy soils. This information may aid in determination of precise herbicide rates for various soil types to allow growers to achieve consistent control of downy brome without injuring winter cereals. Key words: Edaphic factors, cinmethylin, BAY SMY 1500, metribuzin, napropamide, Bromus tectorum L.

Soil water dynamics after fire in a Portuguese shrubland

2006 ◽  
Vol 15 (1) ◽  
pp. 99 ◽  
Author(s):  
Joaquim S. Silva ◽  
Francisco C. Rego ◽  
Stefano Mazzoleni
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Plant Community ◽  
Root Distribution ◽  
Control Plot ◽  
The Other ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Surface Layers ◽  
Before And After

This paper presents a study where soil water content (SW) was measured before and after an experimental fire in a shrubland dominated by Erica scoparia L. in Portugal. Two plots were established: one was kept as a control plot and the other was burned by an experimental fire in June 2001. Measurements were taken before fire (2000), and after fire (2001, 2002, and 2003) at six depths down to 170 cm, from June to December. Measurements before fire allowed comparison of the two plots in terms of the SW differential, using 2000 as a reference. Results for 2001 showed that SW decreased less during the drying season (June–September) and increased more during the wetting season (October–December) in the burned plot than in the control plot. The magnitude of these effects decreased consistently in 2002 and 2003, especially at surface layers. The maximum gain of SW for the total profile in the burned plot was estimated as 105.5 mm in 2001, 70.2 mm in 2002, and 35.6 mm in 2003. The present paper discusses the mechanisms responsible for the increase in SW taking into account the characteristics of the plant community, including the root distribution, and the results of other studies.

Partial cut harvesting and ectomycorrhizae: early effects in Douglas-fir-larch forests of western Montana

1980 ◽  
Vol 10 (3) ◽  
pp. 436-440 ◽  
Author(s):  
A. E. Harvey ◽  
M. J. Larsen ◽  
M. F. Jurgensen
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Douglas Fir ◽  
The Other ◽  
Western Montana ◽  
Root Tips ◽  
Residue Removal ◽  
Larch Forests ◽  
Early Effects

Numbers of ectomycorrhizae were assessed 3 years after harvesting approximately 50% of the overstory in two Douglas-fir-larch stands in western Montana, one was subjected to intensive residue removal, the other broadcast burned 1 year after harvest. Numbers of active ectomycorrhizal root tips were significantly reduced in the broadcast burned stand compared to either the intensively utilized stand or to an adjacent, undisturbed stand. This indicates that on difficult-to-regenerate sites, particularly where soil organic matter is low, it may be advantageous to dispose of slash created in partial cuts by means other than burning.

scholarly journals Differences in soil organic matter and humus of sandy soil after application of biochar substrates and combination of biochar substrates with mineral fertilizers

2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Content ◽  
Humic Substances ◽  
Sandy Soil ◽  
The Other ◽  
Mineral Fertilizers ◽  
Other Hand ◽  
Sheep Manure ◽  
The Impact

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.

scholarly journals Pengaruh Gambut Terbakar Terhadap Beberapa Sifat Fisika Gambut di Kecamatan Tripa Makmur

2020 ◽  
Vol 4 (2) ◽  
pp. 416-425
Author(s):  
Teuku Muhammad Afrizal ◽  
Hairul Basri ◽  
Muhammad Rusli Alibasyah
Keyword(s):  
Organic Matter ◽  
Physical Properties ◽  
Water Content ◽  
Statistical Tests ◽  
Peat Soil ◽  
Rate Of Change ◽  
The Other ◽  
Volume Weight ◽  
Top Soil ◽  
Significant Difference

Abstrak. Gambut mengandung bahan organik yang tinggi. Gambut yang didrainase rentan terhadap kebakaran. Pemanfaatan gambut di Aceh sangat luas. Umumnya, gambut sering dibakar agar dapat dengan cepat dimanfaatkan., khususnya di Kecamatan Tripa Makmur Kabupaten Nagan Raya. Penelitian ini bertujuan untuk melihat seberapa jauh tingkat perubahan sifat fisika gambut terbakar Rawa Tripa Kabupaten Nagan Raya. Hasil penelitian menunjukkan bahwa rata-rata berat volume tertinggi terdapat pada sampel T1 (top soil) yaitu  0,36 g cm-3 dan terendah pada T0 (sub soil) yaitu  0,17 g cm-3. Kadar air tertinggi  terdapat pada sampel T0 (sub soil)  yaitu 234,82% dan terendah pada T1 (top soil) yaitu 81,96%. Porositas tertinggi terdapat pada sampel gambut T0  (sub soil) yaitu 94,93% dan terendah pada T1 (top soil) yaitu 65,28%. Permeabilitas tertinggi terdapat pada T0 (sub soil) yaitu 33,80 cm/jam dan terendah pada T1 (top soil) yaitu 16,10 cm/jam. Hasil uji statistik menunjukkan bahwa ada perbedaan yang signifikan pada parameter berat volume dengan t hitung (3,482) t tabel (1, 943), sedangkan pada parameter lainnya tidak ada perbedaan yang signifikan. Tingkat kematangan gambut di kawasan Tripa Makmur adalah hemik. Kedalaman gambut sebesar 3 meter.  Subsiden tertinggi adalah 100 cm pada gambut terbakar di tahun 2015. Warna  gambut adalah coklat kehitaman. The Effect of Burning Peat on Some of The Physical Porperties of Peat Soil in The Tripa Makmur Sub DistrictAbstract. Peat contains high organic matter. Drained peat is susceptible to fire. The use of peat in Aceh is very broad. Peat is often burned so that it can be quickly utilized especially in Tripa makmur Sub Districk, Nagan Raya Districk. This study aims to see how far the rate of change in the physical properties of peat is burning Rawa Tripa in Nagan Raya District. The results showed that the highest average of volume weight was found in T1(top soil) 0,36 g cm-3 and the lowest in T0(sub soil) 0,17 g cm-3. The highest water content was found inT0(sub soil) 234,82%  and the lowest was on T1(top soil) 81,96%. The highest porosity was found T0(sub soil) 94,93% and the lowest in T1(top soil) 65,28%. The highest permeability is found in T0(sub soil) 33,80 cm/hour and the lowest is on T1(top soil) 16,10 cm/hour. The results of statistical tests show that there is a significant difference in the parameters of volume weight with t count 3,482 t table 1,943, while in the other parameters have no significant differences. The level of maturity in the Tripa Makmur area is hemik. Peat depth of 3 meters. The highest subsidance is 100 cm on burning peat in 2015. The color of this peat is blackish brown. 

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