EFFECT OF TILLAGE REDUCTION AND FERTILIZER ON SOIL MACRO- AND MICROAGGREGATION

1989 ◽  
Vol 69 (3) ◽  
pp. 489-500 ◽  
Author(s):  
A. N. WEILL ◽  
E. MCKYES ◽  
C. R. DE KIMPE
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Geometric Mean ◽  
Size Fraction ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Matter Content ◽  
Corn Production ◽  
Soil Organic Matter Content ◽  
Loam Soil

This study was undertaken to determine the effect of tillage and fertilizer on soil structure in fields under corn production in Quebec. Three types of tillage (moldboard, chisel and zero-till) and two types of fertilizer (manure and inorganic fertilizer) were applied yearly for 6 yr on a clay and a sandy loam soil. Macroaggregation was obtained after dry and wet sieving and microaggregation after sonification. Soil geometric mean diameter and aggregate stability were increased after manure applications and still further by zero-till. The amount of aggregates in each size fraction was affected differently by the fertilizer and tillage treatments. The fraction of organic matter binding the < 250-μm units into > 250-μm units played a greater role in soil aggregation than total soil organic matter content. Key words: Aggregation, manure, organic matter, soil pH, reduced tillage

Leaching of Oxyfluorfen in Container Media

1991 ◽  
Vol 5 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Menashe Horowitz ◽  
Clyde L. Elmore
Keyword(s):  
Sandy Loam ◽  
Organic Matter Content ◽  
Fold Increase ◽  
Matter Content ◽  
Water Volume ◽  
Soil Organic Matter Content ◽  
Potting Medium ◽  
Potting Media ◽  
Loam Soil ◽  
Leaching Experiments

Bentgrass was used to bioassay oxyfluorfen in leaching experiments done in columns of soilless potting media and soils, with herbicide incorporated into the upper 2 to 4 cm. Depth of herbicide leaching increased in order in the following soils: peat and sand (1:1) mix, Stockton clay soil, Yolo fine sandy loam soil, and redwood bark and sand (3:1) mix. Depth of leaching was not related to soil organic matter content. Equilibration experiments showed that peat adsorbed 4 to 5 times more oxyfluorfen than redwood bark. Less leaching was observed in potting mixtures containing peat than bark. Raising the oxyfluorfen dose from 20 to 200 ppmw increased the depth of leaching and concentration of herbicide in the leachate, while a 10-fold increase in water volume had only a limited effect. Twenty ppmw of oxyfluorfen incorporated in the top of a peat-containing potting medium has a low risk of leaching out of the container.

Flumetsulam mobility in two Mississippi soils as influenced by irrigation timing

Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Chris H. Tingle ◽  
David R. Shaw ◽  
Patrick D. Gerard
Keyword(s):  
Organic Matter ◽  
Soil Type ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Laboratory Studies ◽  
Flow Conditions ◽  
Soil Columns ◽  
Irrigation Interval ◽  
Loam Soil

Laboratory studies were conducted to evaluate14C-flumetsulam mobility in two Mississippi soils of varied texture and organic matter content following delays in irrigation. Mobility was evaluated using packed soil columns, 25 cm deep, under unsaturated–saturated flow conditions. Irrigation timings included 0, 3, and 5 d after flumetsulam application. Flumetsulam mobility (defined as the amount collected in leachate) decreased from 45% to no more than 20% of the applied in the Prentiss sandy loam soil when irrigation was delayed 3 or 5 d. With the Okolona soil, flumetsulam recovery in the leachate was 21, 14, and 6%, respectively when irrigation occurred 0, 3, and 5 d after application. Flumetsulam proved to be mobile when irrigation immediately followed application, with 6 to 45% recovered in the leachate from all soils evaluated. The Prentiss soil retained 6% of the applied flumetsulam in the upper 5 cm and the Okolona soil retained 22% when irrigation immediately followed flumetsulam application. When the irrigation interval was delayed at least 3 d, the Okolona soil retained 40% in the upper 5 cm, whereas the Prentiss soil retained 10%. Flumetsulam mobility was dependent on irrigation timing and soil type.

scholarly journals EFFECT OF DITHIOPYR, SEED PLACEMENT. AND SOIL ORGANIC MATTER CONTENT ON GROWTH OF TOLERANT AND SUSCEPTIBLE WEEDS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 587f-587
Author(s):  
Nanik Setyowati ◽  
Leslie A. Weston
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Soil Surface ◽  
Matter Content ◽  
Peat Moss ◽  
Silt Loam ◽  
Soil Organic Matter Content ◽  
Silt Loam Soil ◽  
Seed Placement ◽  
Loam Soil

Dithiopyr (Dimension, Monsanto) is a turfgrass herbicide currently under evaluation for use in ornamentals. Granular herbicide depth and seed placement were evaluated in greenhouse studies with tolerant or susceptible weeds. Dithiopyr was applied preemergence to weeds at the rate of 2.24 kg/ha to Maury silt loam soil. Weed seeds were planted routinely at 0.64 cm depth. Dithiopyr placed at the soil surface or 0.64 cm in depth caused the greatest injury to seedlings, followed by dithiopyr at 1.28 cm depth. Dithiopyr at 2.54 and 3.81 cm below the surface had no effect upon seedling growth. When seeding depth was investigated, seed placed at 0.64, 1.28 or 1.91 cm below the surface showed greatest seedling injury when dithiopyr was routinely applied at 0.64 cm depth. Seed placement on the soil surface resulted in the least injury to weeds. Peat moss was added to Maury silt loam soil and to sand to investigate the influence of organic matter upon activity. Soil with 2% peat resulted in the least injury to selected weed seedlings while sand, and sand plus up to 3% peat showed greatest injury. Sand amended with 5 and 6% peat also resulted in less injury to weed seedlings. Ivy leaf morningglory and KY 31 fescue were most tolerant of dithiopyr while barnyardgrass and large crabgrass were most sensitive. Dithiopyr uptake, translocation and metabolism studies will be conducted with susceptible and tolerant weed and woody ornamental species.

scholarly journals Aggregate stability as affected by short and long-term tillage systems and nutrient sources of a hapludox in southern Brazil

2009 ◽  
Vol 33 (4) ◽  
pp. 767-777 ◽  
Author(s):  
Milton da Veiga ◽  
Dalvan José Reinert ◽  
José Miguel Reichert
Keyword(s):  
Organic Matter ◽  
Crop Residues ◽  
Geometric Mean ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Matter Content ◽  
Tillage Systems ◽  
Soil Layers ◽  
Nutrient Sources ◽  
Mean Diameter

The ability of a soil to keep its structure under the erosive action of water is usually high in natural conditions and decreases under frequent and intensive cultivation. The effect of five tillage systems (NT = no-till; CP = chisel plowing and one secondary disking; CT = primary and two secondary distings; CTb = CT with crop residue burning; and CTr = CT with removal of crop residues from the field), combined with five nutrient sources (C = control, no nutrient application; MF = mineral fertilizers according to technical recommendations for each crop; PL = 5 Mg ha-1 y-1 fresh matter of poultry litter; CM = 60 m³ ha-1 y-1 slurry cattle manure; and SM = 40 m³ ha-1 y-1 slurry swine manure) on wet-aggregate stability was determined after nine years (four sampled soil layers) and on five sampling dates in the 10th year (two sampled soil layers) of the experiment. The size distribution of the air-dried aggregates was strongly affected by soil bulk density, and greater values of geometric mean diameter (GMD AD) found in some soil tillage or layer may be partly due to the higher compaction degree. After nine years, the GMD AD on the surface was greater in NT and CP compared to conventional tillage systems (CT, CTb and CTr), due to the higher organic matter content, as well as less soil mobilization. Aggregate stability in water, on the other hand, was affected by the low variation in previous gravimetric moisture of aggregates, which contributed to a high coefficient of variation of this attribute. The geometric mean diameter of water-stable aggregates (GMD WS) was highest in the 0.00-0.05 m layer in the NT system, in the layers 0.05-0.10 and 0.12-0.17 m in the CT, and values were intermediate in CP. The stability index (SI) in the surface layers was greater in treatments where crop residues were kept in the field (NT, CP and CT), which is associated with soil organic matter content. No differences were found in the layer 0.27-0.32 m. The effect of nutrient sources on GMD AD and GMD WS was small and did not affect SI.

EFFECTS OF SOIL PROPERTIES AND AMENDMENTS ON THE AVAILABILITY OF ZINC IN SOILS

1974 ◽  
Vol 54 (4) ◽  
pp. 369-378 ◽  
Author(s):  
A. J. MACLEAN
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Acid Soil ◽  
Organic Matter Content ◽  
Organic Amendments ◽  
Matter Content ◽  
Sandy Loam Soil ◽  
Loam Soil ◽  
The Mean ◽  
Extractable Zn

In a soil incubation experiment with different rates of Zn, the amounts of Zn extracted with 0.005 M DTPA, 1 M MgCl2, and 0.01 M CaCl2 increased with an increase in the organic matter content of a neutral sandy loam soil and with alfalfa added as an organic amendment. Addition of muck and peat increased the amount of Zn exchanged with 1 M MgCl2 but decreased the amount soluble in 0.01 M CaCl2, whereas addition of clay increased the amount of exchangeable Zn but decreased the amounts in the DTPA and 0.01 M CaCl2 extracts. Liming of an acid sandy loam soil (pH 4.9) to about the neutral point reduced the amounts of extractable Zn markedly. A pretreatment of the soils with phosphate almost invariably increased the amounts of extractable Zn. In a corresponding pot experiment, the highest rate of Zn (250 ppm) reduced the yield of corn slightly, prevented the growth of lettuce, and reduced the yield of alfalfa markedly when these crops were grown successively in the acid soil. The concentration of Zn reached levels of 792 ppm in the corn and 702 ppm in the alfalfa. Addition of 50 ppm Zn to the acid soil restricted the growth of lettuce and increased the concentration of Zn to 523 ppm. Despite discrepancies, the concentrations of Zn in the plants as influenced by soil organic matter, organic amendments and liming were usually in accord with the amounts of Zn extracted from the soils. But the P pretreatment tended to decrease the concentration of Zn in corn and lettuce. The mean weight concentrations of Zn in the three species were correlated significantly with the amounts of Zn extracted with 0.005 M DTPA (r = +0.73), 1 M MgCl2 (r = +0.93) and 0.01 M CaCl2 (r = +0.90).

MOVEMENT OF PICLORAM IN SOIL COLUMNS

1973 ◽  
Vol 53 (3) ◽  
pp. 307-314 ◽  
Author(s):  
R. GROVER
Keyword(s):  
Organic Matter ◽  
Clay Soil ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Columns ◽  
Canadian Prairie ◽  
Prairie Soils ◽  
Loam Soil ◽  
Water Holding

The movement of picloram (4-amino-3,5,6-trichloropicolinic acid) was studied in various Canadian Prairie soils, using soil columns. Picloram was readily leached in all soil types. The movement was greatest in the soil with the lowest organic matter and clay contents, and lowest in black soils that are high in soil organic matter content. It was related, in general, to the adsorptive and water-holding capacities of these soils. The extent of leaching of picloram was also related to the total amount of water applied; the greater the amount o¡ water the greater the downward movement. Increasing the intensity of water increments from 0.25 to 2.5 cm enhanced the movement of picloram in the clay soil but had no effect in the sandy loam. There was little or no difference in the movement of picloram when the herbicide was applied at 2.0 or 0.2 kg/ha, Picloram leached to a greater depth when the sandy loam soil was initially dry than wet and the converse was true for the clay soil. Picloram moved readily upwards when the soil columns were subirrigated.

Behavior and Fate of Metribuzin in Eight Ontario Soils

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 153-160 ◽  
Author(s):  
M. S. Sharom ◽  
G. R. Stephenson
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Distribution Coefficients ◽  
Matter Content ◽  
Soil Persistence ◽  
Muck Soil ◽  
Loam Soil ◽  
Mineral Soils ◽  
Adsorption Desorption

The adsorption, desorption, and mobility of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] in eight Ontario soils were investigated. The distribution coefficients varied from 0.56 for the least adsorptive Fox sandy loam soil to 31.67 for the most highly adsorptive Leamington muck soil. Most of the adsorbed metribuzin was desorbed from the mineral soils after six aqueous extractions, however substantial amounts of the herbicide remained adsorbed on the muck soils after 10 aqueous extractions. The herbicide was relatively mobile in mineral soils but was immobile in the muck soils. Mobility was inversely correlated with the amount of soil organic matter. Bioassay studies indicated that phytotoxicity of metribuzin also decreased with increasing organic matter content of the soil. Persistence of metribuzin was dependent on microbial degradation. In a field study with Guelph loam, the half-life of metribuzin was approximately 3 months.

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply
Sign in / Sign up

Export Citation Format

Share Document