Norflurazon adsorption and dissipation in three southern soils

Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 301-306 ◽  
Author(s):  
William T. Willian ◽  
Thomas C. Mueller ◽  
Robert M. Hayes ◽  
David C. Bridges ◽  
Charles E. Snipes

Norflurazon adsorption and dissipation under field and laboratory conditions, and distribution within the soil profile were determined in three soils representative of cotton-growing regions of the southeastern U.S. Norflurazon adsorption was greater in soil from 0 to 8 cm in a Lexington silt loam (Tennessee) and a Beulah silt loam (Mississippi) than in a Dothan loamy sand (Georgia). Adsorption was directly related to organic matter. Norflurazon degradation under controlled conditions in soil from 0 to 8 cm from each state was not different among locations, with half-lives ranging from 63 to 167 d. Degradation at 30 C in soil from the 30- to 45- and 60- to 90-cm depths was not different among locations, and was slower at the 60- to 90-cm depth than in surface soil. Norflurazon dissipation was more rapid under field conditions than under laboratory conditions, with half-lives ranging from 7 to 79 d in the 0- to 8-cm soil horizon. Dry field conditions slowed norflurazon dissipation. Norflurazon was not detected below 15 cm in the profile in any soil, and concentrations in the 8- to 15-cm soil zone were < 36 ppbw 112 d after treatment.

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 183-189 ◽  
Author(s):  
William T. Willian ◽  
Thomas C. Mueller ◽  
Robert M. Hayes ◽  
Charles E. Snipes ◽  
David C. Bridges

Fluometuron adsorption and dissipation under field and laboratory conditions, and distribution within the soil profile was determined in 3 soils from Tennessee, Mississippi, and Georgia that are representative of the cotton-growing regions of the southeastern United States. Fluometuron adsorption was correlated with organic matter, but not with clay content or soil pH. First-order kinetics explained fluometuron dissipation under field and controlled conditions (r2≥ 0.82). Field dissipation of fluometuron was slower under dry conditions. Fluometuron was not detected below 15 cm in the soil profile in any soil, and concentrations in the 8- to 15-cm soil zone were < 15 ppbw 112 d after treatment. Fluometuron dissipation was more rapid in soil from the 0- to 8-cm depth in Tennessee soil than in Mississippi soil under controlled conditions. Dissipation was more rapid under field conditions than under laboratory conditions at 2 of 3 locations. Fluometuron half-lives in soils from the 0- to 8-cm depth ranged from 9 to 28 d under field conditions and from 11 to 43 d in the laboratory. Fluometuron dissipation in soils from 30- to 45- and 60- to 90-cm depths was not different among soils, with half-lives ranging from 58 to 99 d under laboratory conditions. Fluometuron half-life was positively correlated with soil depth and inversely correlated with organic matter. These data indicate that organic matter, soil depth, and environmental conditions affect fluometuron dissipation.


1969 ◽  
Vol 58 (2) ◽  
pp. 197-210
Author(s):  
K. Dale Ritchey ◽  
Richard H. Fox

Greenhouse experiments with maize were carried out to see if the reported infertility of some subsoils could be improved with mineral fertilization and efficient watering. It was shown that the Nipe soil series (Typic Acrorthox; clayey, oxidic, isohyperthermic) exposed subsoil was as productive as the Carreras series (Aquic Tropohumult; clayey, kaolinitic, isohyperthermic) surface soil when N, K, micronutrients and 600 ppm P were added and the pots were watered by means of wicks. Carreras subsoil, when limed and fertilized with N, K, 300 ppm P, 100 ppm Mg and 36 ppm Zn produced as well as Carreras surface soil, even though it contained only about one-third as much organic matter. A comparison among eight surface and subsoils showed that yields on limed, liberally fertilized, well-watered Los Guineos series (Epiaquic Humoxic Tropohumult; clayey, kaolinitic, isothermic) surface soil, Carreras surface soil, Piña series (Psammentic Haplorthox; sandy, isohyperthermic) surface soil, Los Guineos subsoil, Piña subsoil and Catalina series (Tropeptic Haplorthox; clayey, oxidic, isohyperthermic) surface soil were not significantly different. However, the yield on the least productive of two Catalina subsoils was only 64 percent of the yield on the Los Guineos surface soil. But with the addition of Zn and slightly over 1,000 ppm P, greenhouse pot yields on the two soils were essentially the same. Field experiments will be necessary to determine optimum P rates under field conditions. It was concluded that the productivity in greenhouse pots of surface and subsoils of the Ultisols and Oxisols studied can all be brought to the same high level, provided adequate mineral fertilization (including Zn and high P rates), lime and water management are used.


2017 ◽  
Vol 4 ◽  
pp. 31 ◽  
Author(s):  
Ν.Ε. Roditakis

The effectiveness of Bacillus thuringiensis Berliner var. kurstaki (Dipel Abbot Lab.) against the grape berry moth (Lobesia botrana Den. & Shiff.) was evaluated under laboratory and field conditions. Under laboratory conditions (24±0.5°C, 55±5% r.h., 2,000 Lux, and 16 hours light daily) B. thuringiensis was compared to triflumuron and methomyl on egg hatching and shallow entries per grape berry. B. thuringiensis had no effect on egg hatching while methomyl and triflumuron had ovicidal action. Shallow entries per grape berry were 0.9-1, 0, 0 and 4.55 for B. thuringiensis, triflumuron, methomyl and control, respectively. Under field conditions, using as criteria for the timing of sprays: a. pheromone and food trap catches and b. visual counting of egg laying and a threshold of 20-30 eggs/100 grapes, two applications of B. thuringiensis at Kastelli Pediados in 1981 and four at Peza in 1982 were made both at the 2nd and 3rd flights. Its effectiveness was 96-100% and 92% at Kastelli Pediados and 73-75% at Peza.


Author(s):  
Emilio Ritoré ◽  
Bruno Coquelet ◽  
Carmen Arnaiz ◽  
José Morillo ◽  
José Usero

AbstractThe present study determined the most effective surfactants to remediate gasoline and diesel-contaminated soil integrating information from soil texture and soil organic matter. Different ranges for aliphatic and aromatic hydrocarbons (> C6–C8, > C8–C10, > C10–C12, > C12–C16, > C16–C21, and > C21–C35) in gasoline and diesel fuel were analyzed. This type of analysis has been investigated infrequently. Three types of soils (silty clay, silt loam, and loamy sand) and four surfactants (non-ionic: Brij 35 and Tween 80; anionic: SDBS and SDS) were used. The results indicated that the largest hydrocarbon desorption was 56% for silty clay soil (SDS), 59% for silt loam soil (SDBS), and 69% for loamy sand soil (SDS). Soils with large amounts of small particles showed the worst desorption efficiencies. Anionic surfactants removed more hydrocarbons than non-ionic surfactants. It was notable that preferential desorption on different hydrocarbon ranges was observed since aliphatic hydrocarbons and large ranges were the most recalcitrant compounds of gasoline and diesel fuel components. Unlike soil texture, natural organic matter concentration caused minor changes in the hydrocarbon removal rates. Based on these results, this study might be useful as a tool to select the most cost-effective surfactant knowing the soil texture and the size and chemical structure of the hydrocarbons present in a contaminated site.


Irriga ◽  
2005 ◽  
Vol 10 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Polyanna Mara de Oliveira ◽  
Antônio Marciano da Silva ◽  
Gilberto Coelho ◽  
Ricardo Augusto da Silva

ANÁLISE COMPARATIVA DA CARACTERIZAÇÃO FÍSICO –HÍDRICA DE UM LATOSSOLO VERMELHO DISTRÓFICO IN SITU E EM LABORATÓRIO  Polyanna Mara de Oliveira; Antônio Marciano da Silva; Gilberto Coelho; Ricardo Augusto da SilvaDepartamento de Engenharia, Universidade Federal de Lavras ,Caixa Postal 37, CEP 37200-000, , Lavras, MG,  [email protected]  1 RESUMO Neste trabalho estudaram-se métodos para a estimativa da umidade representativa da capacidade de campo e da condutividade hidráulica não saturada para o Latossolo Vermelho Distrófico, trabalhando com dois métodos, o de perfil instantâneo (HILLEL et al., 1972) e o método empírico de Mualem (1976). Em laboratório foram realizadas a análise granulométrica, densidade do solo, porosidade (macro e microporosidade) e a curva característica de retenção, e em campo, determinaram-se a umidade na capacidade de campo e a condutividade hidráulica. Os resultados encontrados permitem afirmar que a caracterização físico-hídrica do solo em condições de campo mostrou-se mais precisa e confiável em relação às determinações de laboratório sendo que a estimativa da condutividade hidráulica mostrou-se mais consistente com outros atributos do solo e mais representativa da realidade do que aquela baseada em análises laboratoriais. Embora a metodologia de Mualem (1976) possa ser aplicada desde a umidade de saturação até o ponto de murcha permanente, a mesma não mostrou sensibilidade para registrar a influência da macroporosidade sobre a condutividade hidráulica do solo. A estimativa da umidade na capacidade de campo “in situ” ratifica também a melhor performance do método de campo em relação ao laboratorial. UNITERMOS: condutividade hidráulica, capacidade de campo, curva de retenção de água, drenagem interna do solo, atributos físicos do solo.  OLIVEIRA, P. M. de; SILVA, A. M. da; COELHO, G.; SILVA, R. A. COMPARATIVE ANALYSE OF THE PHYSICAL AND WATER CHARACTERIZATION IN FIELD AND LABORATORY CONDITIONS OF DISTROFIC RED LATOSSOL  2 ABSTRACT The aim of this work was to study methods to determine significant moisture for field capacity and non-saturated hydraulic conductivity in dystrophic latossol soil using two methods: internal drainage method (Hillel et al., 1972) and empiric method (Mualem, 1976). Granulometric analysis, soil density, porosity (macro and micro porosity) and characteristic retention curve were determined in laboratory; moisture for field capacity and hydraulic conductivity were determined in field conditions. The results showed that physical and hydraulic soil characterization in field conditions is more accurate and reliable than in lab conditions; hydraulic conductivity determination infield conditions was more consistent with other soil attributes and more realistic than the one based on laboratory conditions. Although Mualem’s method (1979) may be used for saturation moisture as well as for permanent internal drainage, it has not presented the same sensitivity to determine the influence of macro porosity on soil hydraulic conductivity. Moisture determination for field capacity under field conditions also corroborates better performance for field methods than laboratory ones.  KEYWORDS: hydraulic conductivity, field capacity, water retention curve, soil internal drainage, soil physical properties 


2014 ◽  
Vol 6 (4) ◽  
pp. 368-372
Author(s):  
Edita Mažuolytė-Miškinė ◽  
Ilona Grigalavičienė ◽  
Violeta Gražulevičienė

The article presents investigation into the rate of the biodegradation of cattle horn shavings used as plant fertilisers in soil and describes their effect on the agrochemical properties of soil. Research was carried out under field and laboratory conditions. The field experiment was conducted on the farm of organic production at the Centre of Agroecology of Aleksandras Stulginskis University, Lithuania in May – August of 2012. The average air temperature during the experiment was 16.45 °C. Soil pH, specific electrical conductivity value and organic matter content in soil samples were measured. The extent of the biodegradation of cattle horn shavings in soil and in the thermostat under laboratory conditions at the temperatures of 5 °C and 20 °C and at 40% soil moisture was compared. The obtained results indicate that mass changes in cattle horn shavings in the process of biodegradation under field and laboratory conditions (at an ambient temperature of 5 °C and 20 °C) are similar: after 120 days, the mass of horn shavings decreased by 37.3%, 36.2%, and 34.5% respectively. The largest changes in soil pH and organic matter content were observed during the first 60 days. During the biodegradation of horn shavings under field conditions after 40 days, organic matter content in soil increased from 2.53 to 3.20% and soil pH decreased from 8.0 to 7.1. Smaller changes were observed under laboratory conditions. Ištirta augalams tręšti naudojamų galvijų ragų drožlių suirimo sparta dirvožemyje ir jų įtaka dirvožemio savybėms. Bandymai atlikti lauko (natūraliomis gamtinėmis) ir laboratorinėmis sąlygomis. Lauko eksperimentas vykdytas 2012 m. gegužės–rugpjūčio mėnesiais Aleksandro Stulginskio universiteto Agroekologijos centro ekologinės gamybos ūkyje. Vidutinė oro temperatūra bandymų laikotarpiu buvo 16,45 °C. Laboratorinio eksperimento metu buvo nustatomas ragų drožlių suirimo greitis dirvožemyje esant 5 ir 20 °C aplinkos temperatūrai ir 40 % dirvožemio drėgniui. Atlikti dirvožemio pH, savitojo elektrinio laidžio ir organinės medžiagos kiekio dirvožemyje tyrimai. Nustatyta, kad ragų drožlių masės pokyčiai biodegraduojant drožlėms lauko sąlygomis ir laboratorinėmis sąlygomis, esant 5 ir 20 °C aplinkos temperatūrai, yra panašūs: ragų drožlių masė po 120 parų sumažėjo atitinkamai 37,3 %, 36,2 %, ir 34,5 %. Didžiausi dirvožemio pH ir organinės medžiagos kiekio pokyčiai vyko per pirmąsias 60 parų. Ragų drožlėms biodegraduojant lauko sąlygomis organinės medžiagos kiekis dirvožemyje šiuo laikotarpiu padidėjo nuo 2,53 ik 3,20 %, o dirvožemio pH sumažėjo nuo 8,0 iki 7,1. Atliekant bandymus laboratorinėmis sąlygomis šie pokyčiai buvo mažesni.


1970 ◽  
Vol 7 (2) ◽  
pp. 403-410 ◽  
Author(s):  
MA Mojid ◽  
SMT Mustafa ◽  
GCL Wyseure

This study investigated the growth, yield and water use efficiency of wheat in five soil textures obtained by amendment. This was done by executing field experiments that consisted of five soil treatments with 3 replications. The treatments were: (i) T1: loamy sand, (ii) T2: sandy loam, (iii) T3: loam 1, (iv) T4: loam 2 and (v) T5: silt loam (used as amendment). Wheat was cultivated with four irrigations and recommended dose of fertilizers. Increased porosity and pore size distribution in the finer-textured soils improved soil structure with a consequent improvement in soil physico-chemical properties. The saturated hydraulic conductivity decreased significantly, while field capacity and water retention increased considerably as the textured of the soil become finer. The improved water and organic matter contents in treatments T2 - T5 stimulated growth of wheat and caused significant (p = 0.05) increase in leaf area index, plant height, number of total and effective tillers per plant, spike length, number of spikelets per spike, number of grains per spike, grain yield, and biological yield compared to T1. The roots grew and branched profusely in the soil of high moisture and organic matter content; the largest root biomass was in the upper 20 cm of soil depth in all the treatments. The enhanced vegetative growth in terms of plant height and number of tillers per plant helped increasing straw yield, which together with yield attributing characters, improved the biological yield in the finer textured soils. Treatments T2 - T4 produced 1.2 to 2.8 times higher grain and biological yields compared to T1. The irrigation requirement and total water used in a treatment increased as the texture of a soil became coarser. Treatment T2 saved 1 to 13.6% and T3- T5 saved 29.4 to 57.5% irrigation water compared to T1. T1 provided the lowest water use efficiency, which increased gradually as the texture became finer. All treatments except T1 maintained improved water regime. Keywords: Clay content; Soil water; Wheat cultivation; Growth and yield; Water use efficiency DOI: 10.3329/jbau.v7i2.4753 J. Bangladesh Agril. Univ. 7(2): 403-410, 2009


1924 ◽  
Vol 14 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Selman A. Waksman

Various investigations on the decomposition of organic matter in the soil have brought out the fact that there exists a more or less constant ratio between the carbon and nitrogen content of the soil, whatever the ratio between these elements in the organic matter originally added to the soil. This ratio varies from 8: 1 to 12: 1, i.e. for every 8 to 12 parts of carbon, there exists in the soil one part of nitrogen; the average ratio is about 10 to 1. Brown and O'Neal (1923), for example, found that the ratio of the carbon to the nitrogen in a Carrington loam is 12: 1 to 13: 1, while, in the case of a Tama silt loam, the ratio may go down to 10: 1. According to Sievers (1923), the ratio of carbon to nitrogen in the soil is about 11·6: 1. Russell (1923) stated that, although there is about 40 times as much carbon as nitrogen in the original plant residues, the ratio will drop down to 10 to 1, before these residues have been very long in the soil. This ratio seemed to be in a stable position, for which no explanation could be suggested. Fraps (1922) found the ratio of carbon to nitrogen in the surface soil to be 9·2: 1 and in the subsoil 8·3: 1; he suggested, therefore, to judge the percentage of organic carbon in the soil from the percentage of nitrogen present.


2015 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Behnaz Hosseini-Tabesh ◽  
Ahad Sahragard ◽  
Azadeh Karimi-Malati

Abstract Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae) feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h) and field conditions (23-43°C, and relative humidity of 27-95%). The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r), net reproductive rate (R0), and the finite rate of increase (λ) under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days) between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops


Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 576-582 ◽  
Author(s):  
Gary Basham ◽  
Terry L. Lavy ◽  
Lawrence R. Oliver ◽  
H. Don Scott

Field persistence of imazaquin {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid} applied preemergence as high as 16 times the 0.14 kg ai/ha recommended rate was studied at two locations in Arkansas in 1984 and 1985. Rapid dissipation of these high rates occurred on the Taloka silt loam under hot, dry field conditions in 1984 when no rainfall occurred for 2 weeks after application. In 1985, when furrow irrigation was applied 7 days after application, imazaquin phytotoxicity was greater and dissipation was delayed. Imazaquin persistence and soil adsorption were greater on Sharkey silty clay than on Taloka silt loam. Following 3- and 8-cm irrigation, 84 and 78%, respectively, of the14C-labeled imazaquin remained in the surface 5 cm, but in plots covered between rainfalls and receiving 8 cm rain, 74% leached out of this top layer. Since nonincorporated imazaquin dissipated rapidly under hot, dry field conditions, carryover into the next growing season or leaching below the plow layer would not be expected. However, in cool, wet conditions immediately after application, the weakly adsorbed imazaquin molecule was readily bioavailable and mobile in the soil profile.


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