In field survival of Rhizoctonia solani in soil and in diseased sugarbeets

1976 ◽  
Vol 22 (7) ◽  
pp. 983-988 ◽  
Author(s):  
Leonard J. Herr
Keyword(s):  
Rhizoctonia Solani ◽  
Sandy Loam ◽  
Soil Surface ◽  
Growing Season ◽  
Early Spring ◽  
Inoculum Density ◽  
Silty Clay ◽  
Loam Soil ◽  
Low Levels ◽  
Silty Clay Soil

Persistence of Rhizoctonia solani in the field was investigated by ascertaining survival (competitive saprophytic activity) in soil and survival in diseased plants. Except for one instance, low levels of R. solani survived overwinter in artificially and naturally infested soils. In a sandy loam soil, cropped to sugarbeets, inoculum density increased throughout the growing season from low early spring levels to high levels in July and August. In a silty clay soil, cropped to sugarbeets, inoculum density remained low with only a slight increase throughout the growing season. Survival of R. solani in diseased sugarbeets placed on the soil surface was greater than survival in diseased beets buried in soil. Little reduction in percentages of beets yielding R. solani colonies took place from November to April in either buried or unburied beets. The major reduction in survival of R. solani in buried beets occurred during the 6-week interval from April to June.

The effect of tillage and KCl addition on pH, conductance, NO3-N, P, K and Cl distribution in the soil profile

1994 ◽  
Vol 74 (3) ◽  
pp. 307-314 ◽  
Author(s):  
C. A. Grant ◽  
L. D. Bailey
Keyword(s):  
Soil Profile ◽  
Clay Soil ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Silty Clay ◽  
Zero Tillage ◽  
Tillage Systems ◽  
Fine Sandy Loam ◽  
Loam Soil ◽  
Silty Clay Soil

Distribution of NO3, P, K, Cl, pH and conductance through the soil profile were measured on two soil types after 4 yr of crop production using zero tillage (ZT) or conventional tillage (CT), with or without addition of KCl. All plots received N and P fertilizer each year as banded applications. Surface concentrations of NO3-N were higher under ZT than CT, particularly on the fine sandy loam soil. Accumulation of NO3-N also occurred in the 60- to 120-cm zone, under both tillage systems in both soils. Carryover of NO3-N was substantially greater on the silty clay than the fine sandy loam soil. Phosphate accumulated at the depth of band application in both soils under both tillage systems. Potassium concentration was generally higher under ZT than CT in the surface 15 cm of both soils, presumably due to surface retention of K from fertilizer applications and crop residues. Chloride was higher under ZT than CT in the surface 5 cm of both soils, but was higher under CT than ZT in the 30- to 60-cm and 60- to 120-cm depths in the silty clay soil, if KCl had been applied. The pH on both soils under both tillage systems was reduced in the 10- to 12.5-cm soil depth, corresponding to the zone of fertilizer application. On the silty clay soil, pH was higher under ZT than CT in the 10- to 15-cm depth and tended to be higher under ZT than CT at all depths below 15 cm. Conductance was not influenced by tillage in either soil. Application of KCl increased K and Cl concentrations in the surface 15 cm on both soils. Concentration of Cl was increased to 120 cm in both soils, indicating the mobility and leaching potential of this anion. Conductance and pH were increased in the 2.5- to 5.0-cm and 10- to 12.5-cm depths by KCl application in the fine sandy loam soil, but on the silty clay soil, only conductance was increased. Key words: Zero tillage, nutrient stratification, pH stratification

MICROBIAL DEGRADATION OF 2,2-DICHLOROPROPIONIC ACID IN FIVE SOILS

1964 ◽  
Vol 10 (6) ◽  
pp. 843-852 ◽  
Author(s):  
Donald D. Kaufman
Keyword(s):  
Microbial Degradation ◽  
Sandy Loam ◽  
Culture Conditions ◽  
Exchange Capacity ◽  
Silty Clay ◽  
Effective Microorganisms ◽  
Enrichment Technique ◽  
Loam Soil ◽  
Silty Clay Soil ◽  
Plant Bioassays

The microbial degradation of 2,2-dichloropropionic acid (dalapon) in five soils was observed under greenhouse and laboratory conditions. Oat plant bioassays revealed that under greenhouse conditions (28 °C) dalapon persisted only 4–8 days in a muck soil, 8–16 days in loam and silty clay loam soils, 16–32 days in sandy loam soil, and 32–64 days in a silty clay soil. An enrichment technique was used to isolate microorganisms effective in the degradation of dalapon from each soil. Although differences in microbial populations among the five soils examined were evident, each soil possessed one or more organisms capable of rapidly degrading dalapon under pure culture conditions. Dalapon degradation by effective microorganisms was affected by organic matter level, pH, cation exchange capacity, and aeration.

scholarly journals Mobility, Degradation, and Uptake of Indaziflam under Greenhouse Conditions

HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1216-1221
Author(s):  
Amir M. González-Delgado ◽  
Manoj K. Shukla
Keyword(s):  
Retention Time ◽  
Preferential Flow ◽  
Sandy Loam ◽  
Soil Surface ◽  
Growing Season ◽  
Application Rate ◽  
Homogeneous Porous Media ◽  
Application Rates ◽  
Loam Soil ◽  
Irrigation Volume

The objectives of this study were to evaluate the leaching, degradation, uptake, and mass balance of indaziflam, as well as its potential to produce phytotoxicity effects on young pecan trees. Pecan trees were planted in pots with homogeneous porous media (sandy loam soil), preferential flow channels open to the soil surface, and shallow tillage at the soil surface. Pots were treated with indaziflam at two application rates of 25 and 50 g a.i./ha in 2014 and 2015. Each pecan tree was irrigated with 7 L of water every 2 weeks during the growing season. An irrigation volume of 2 L was used to maximize indaziflam retention time in the soil from Dec. 2015 until the end of the trees’ dormant stage. In 2014, leachate samples were collected after each irrigation for quantifying indaziflam mobility. Soil samples were collected at depths of 0 to 12 and 12 to 24 cm after 45, 90, and 135 days of indaziflam application, and leaf samples were collected at the end of the growing season to quantify mobility and uptake. Indaziflam was detected in leachate samples, and the leaf indaziflam content increased with increasing application rate. Indaziflam and its breakdown products were detected at both sampling depths. Mass recovery and half-life values for indaziflam in the soil ranged from 38% to 68% and 63 to 99 days, respectively. No phytotoxicity effects were observed from increasing application rate and retention time of indaziflam in the soil. Most of the applied indaziflam was retained in the soil at shallow depth.

scholarly journals Soil Texture Alters the Impact of Salinity on Carbon Mineralization

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Ruihuan She ◽  
Yongxiang Yu ◽  
Chaorong Ge ◽  
Huaiying Yao
Keyword(s):  
Soil Texture ◽  
Clay Soil ◽  
Sandy Loam ◽  
Microbial Community Composition ◽  
Clay Content ◽  
Interactive Effects ◽  
Silty Clay ◽  
C Mineralization ◽  
Negative Effect ◽  
Silty Clay Soil

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.

Examination of the Penetration of Enteric Viruses in Soils under Simulated Conditions in the Laboratory

1985 ◽  
Vol 17 (10) ◽  
pp. 197-199 ◽  
Author(s):  
P. H. Jørgensen
Keyword(s):  
Sewage Sludge ◽  
Unsaturated Soil ◽  
Sandy Loam ◽  
Soil Column ◽  
Enteric Viruses ◽  
Soil Surface ◽  
Coxsackievirus B3 ◽  
Soil Columns ◽  
Sand Column ◽  
Loam Soil

In two different unsaturated soil columns percolated with artificial rainwater under simulated aerated conditions, transport of coxsackievirus B3 and adenovirus 1 below 3.5 cm under the soil surface could not be demonstrated. The viruses were applied to the columns as seeded sewage sludge. Under saturated conditions transport of water-suspended coxsackievirus B3 was faster in a soil column with sandy loam soil than in a diluvial sand column.

Protecting Cotton (Gossypium hirsutum) from Fluometuron Injury with Seed Protectants

Weed Science ◽  
1991 ◽  
Vol 39 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Billy R. Corbin ◽  
Robert E. Frans
Keyword(s):  
Growth Regulators ◽  
Field Experiments ◽  
Clay Soil ◽  
Yield Reduction ◽  
Silty Clay ◽  
Silt Loam ◽  
Chlormequat Chloride ◽  
Mepiquat Chloride ◽  
Loam Soil ◽  
Silty Clay Soil

Field experiments were conducted in 1986 and 1987 to evaluate the potential of growth regulators mepiquat chloride and chlormequat chloride as seed treatments to protect cotton from fluometuron injury. Fluometuron at two and three times the recommended use rate reduced cotton stand and height on Taloka and Convent silt loam soils both years. Cotton grown on a Sharkey silty clay soil was not injured by fluometuron. Mepiquat chloride and chlormequat chloride increased cotton stands on a Taloka silt loam soil when averaged over rates and years. In general, fluometuron injury to cotton was not reduced by treating seed with 1000 ppmw concentrations of chlormequat chloride or mepiquat chloride. Chlormequat chloride reduced chlorosis and necrosis of cotton treated with fluometuron, but neither growth regulator eliminated cotton injury or yield reduction caused by fluometuron at two or three times the recommended rates.

Subsurface Application and Shallow Incorporation of Herbicides on Cotton

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 494-498 ◽  
Author(s):  
A. F. Wiese ◽  
E. B. Hudspeth
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Sandy Loam ◽  
Soil Surface ◽  
Sandy Loam Soil ◽  
Soil Types ◽  
Loam Soil

In a 3-year study on four soil types, subsurface application just ahead of a planter with a device that removed the top from the bed, applied a band of spray, and covered the band with soil reduced weed control in cotton (Gossypium hirsutum L.) obtained with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne), 3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea (norea), dimethyl-2,3,5,6-tetrachloroterephthalate (DCPA), and 1,1-dimethyl-3(α,α,α,-trifluoro-m-tolyl)urea (fluometuron) compared to applications on the soil surface. This machine improved weed control with α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). Shallow incorporation, with two helical blades, after planting increased weed control with trifluralin, diuron, and DCPA by 10% or more over the surface applications. This incorporator increased weed control obtained with prometryne and norea 5%. Very shallow incorporation, with metal tines, after planting improved weed control obtained with trifluralin and DCPA 18 and 11%, respectively. Weed control with norea was increased 7%, but metal tines did not appreciably affect weed control obtained with prometryne, diuron, or fluometuron. Compared to surface applications, incorporation increased cotton injury with diuron, norea, prometryne, and fluometuron on sandy loam soil.

The role of seed reproduction in the dynamics of established populations of Hieracium floribundum and a comparison with that of vegetative reproduction

1975 ◽  
Vol 53 (24) ◽  
pp. 3022-3031 ◽  
Author(s):  
A. G. Thomas ◽  
H. M. Dale
Keyword(s):  
Population Dynamics ◽  
Seedling Establishment ◽  
Vegetative Reproduction ◽  
Soil Surface ◽  
Growing Season ◽  
Population Based ◽  
Early Spring ◽  
Viable Seed ◽  
Density Patch

In the crowded parts of patches of Hieracium floribundum Wimm. and Grab., which were established for at least a decade in an ungrazed pasture, 7–10% of the population (3700 individuals/m2) flowered. Of the plants that flowered, 94% were alive a year later, but only 5% of these flowered. Abortion of flower heads was common; one half of all those which were initiated in early June had aborted by flowering time in early July. Freshly dispersed seed had a viability of 57%, which was reduced to 17% a year later, after its storage close to the soil surface. Less than 6% of the viable seed was innately dormant. Dry, laboratory-stored seed retained its viability for the year but was slower to germinate than soil-stored seed. In field conditions, germination was temperature inhibited during most of the growing season. Maximum daytime microsite temperatures of less than 32 °C, which is necessary for germination, were found to occur only in early spring and late fall. Successful seedling establishment accounts for 1% of the individuals in a crowded population. Based on the maximum sexual reproduction from plants in crowded populations, a seed has a probability of 1 in 20 000 of becoming an established seedling. A model of population dynamics in a high-density patch traces the fate of seedling establishment, surviving adults, and stolon-derived rosettes for a single year.

Ammonia volatilization from surface-applied livestock slurry as affected by slurry composition and slurry infiltration depth

2006 ◽  
Vol 144 (3) ◽  
pp. 229-235 ◽  
Author(s):  
S. G. SOMMER ◽  
L. S. JENSEN ◽  
S. B. CLAUSEN ◽  
H. T. SØGAARD
Keyword(s):  
Soil Water ◽  
Dry Matter ◽  
Sandy Loam ◽  
Soil Water Potential ◽  
Soil Surface ◽  
Pig Slurry ◽  
Fertilizer Value ◽  
Loam Soil ◽  
Water Values ◽  
Slurry Composition

Volatilization of ammonia (NH3) from slurry applied in the field is considered a risk to the environment and reduces the fertilizer value of the slurry. To reduce volatilization a better understanding of the slurry–soil interaction is needed. Therefore, the present study focuses on measuring NH3 volatilization as affected by differences in infiltration. Livestock slurries with different dry matter (DM) composition and viscosity were included in the experiments by using untreated cattle and pig slurry, pig slurry anaerobically digested in a biogas plant and pig slurry anaerobically digested and physically separated. NH3 volatilization was measured using dynamic chambers and related to infiltration of the livestock slurries in the soil by measuring chloride (Cl−) and Total Ammoniacal Nitrogen (TAN=ammonium (NH4+)+NH3) concentrations in soil at different depths from 0·5 to 6·0 cm from the soil surface. The slurries were applied to sandy and sandy-loam soils packed in boxes within the chambers. There were no significant differences in relative volatilization of NH3 from untreated cattle and pig slurries, but anaerobic digestion of pig slurry increased volatilization due to increases in pH. However, physical separation of the digested slurry reduced the volatilization compared with untreated slurry, due to increased infiltration. In general, the volatilization decreased significantly with increased infiltration. The present study shows that NH3 volatilization from applied slurry can be related to infiltration and that infiltration is related to slurry composition (i.e. DM content and particle size distribution) and soil water content. The infiltration of liquid (measured by Cl− infiltration) was affected by soil water potential, therefore, Cl− infiltrated deeper into the sandy loam soil than the sandy soil at similar gravimetric soil water values. Dry matter (DM) and large particles (>1 mm) of the slurry reduced infiltration of liquid. A high proportion of small particles (<0·025 mm) facilitated infiltration of TAN.

EFFECTS OF IRRIGATION AND NITROGEN ON A NATURAL PASTURE SWARD

1978 ◽  
Vol 58 (2) ◽  
pp. 347-356
Author(s):  
W. N. BLACK
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Field Capacity ◽  
Early Spring ◽  
Naturally Occurring ◽  
Natural Pasture ◽  
Loam Soil ◽  
Grazing Period

Irrigation and nitrogen (N) requirements of a natural pasture sward were studied on a Charlottetown sandy loam soil over a 5-yr period. The soil moisture content at the 0-to 15- and 15- to 30-cm depths was determined at from 7- to 10-day intervals, while irrometer soil moisture readings at 15-, 30-, and 45-cm depths were recorded more frequently during the grazing seasons. Soil moisture content in irrigated plots averaged 92 and 94% of field capacity, respectively, at 0- to 15- and 15- to 30-cm sampling depths. In non-irrigated plots, corresponding values were 77 and 82%. N treatments resulted in significant dry matter (DM) increases over untreated plots. Yield differences among plots receiving 56, 84, and 112 kg of N/ha in mid-June and again in mid-August were not significant. Early spring and September applications of N at 56 kg/ha, combined with mid-June and early August supplements of N at 84 kg/ha were superior to all other treatments in prolonging the grazing period. Neither irrigation nor N affected the characteristic yield decline of naturally occurring forage species in mid- and late-season. Mean DM production for the 5-yr period, and for years, showed no significant N treatment × moisture level interaction. While irrigation failed to increase yields significantly, livestock preferred to graze the irrigated plots. As a result of less competition from grasses, volunteer white clover became better established, and constituted a larger percentage of the sward than on non-irrigated plots.

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