PERSISTENCE AND AVAILABILITY OF PARAQUAT IN A LETHBRIDGE CLAY LOAM SOIL

1985 ◽  
Vol 65 (3) ◽  
pp. 523-529 ◽  
Author(s):  
J. R. MOYER ◽  
C. W. LINDWALL

To determine the capacity of the Lethbridge soil to inactivate paraquat, applications equivalent to a maximum of 3000 kg/ha of paraquat were made in growth chamber and field experiments. In the growth chamber and field, more than 600 and 1000 kg/ha, respectively, of paraquat in one application were required to reduce wheat growth by 10%. Paraquat residue levels in the field soil did not decrease after the first summer. Paraquat residue was not found in wheat grain growing in soil with 1650 kg/ha of paraquat in the 0–15 cm layer, but it was detected in plant leaves. The paraquat associated with plant leaves could have resulted from contamination of the leaves by soil rather than from translocation from roots to leaves. The 500 kg/ha rate of paraquat reduced the cation exchange capacity by 5%; however, further paraquat additions did not cause additional reductions. Paraquat could likely be applied for several hundred years at currently recommended rates for weed control on chemical fallow and not exceed the ability of Canadian Prairie soils to inactivate it. Key words: Paraquat, persistence, availability, inactivation, wheat, soil

1989 ◽  
Vol 69 (1) ◽  
pp. 23-30 ◽  
Author(s):  
L. D. BAILEY

The study was conducted to determine whether Bradyrhizobium japonicum can over-winter in Canadian prairie soils, and whether prolonged storage in soil exposed to various environmental conditions affects its nodulating activity. In 1984, Maple Amber, an early-maturing Canadian soybean cultivar was grown in the field on two soils that had never been contaminated with B. japonicum. Two single strains and a commercial mixture of four strains were used as inoculants. In 1985, the soils were cropped again to soybean, but the 1984 inoculated plots were split to permit noninoculated and inoculated treatments. In both years, the inoculants increased seed yield and protein content over the noninoculated treatments. Plants grown on soils inoculated in 1984, but not in 1985, had no nodules, indicating that the Rhizobia did not survive over the winter; seed yield and protein content were similar to plants grown on soils that were never inoculated. Further, the two strains of B. japonicum, 61A148 and 61A196 were more effective than the multistrain inoculant, producing more nodules and greater seed yield, but similar protein content. In the fall of 1984, soil was removed from the inoculated and noninoculated plots and subjected to storage treatments prior to cropping to inoculated soybeans in a growth chamber. Immediate cropping of soils in the growth chamber, following removal from the field, showed that Bradyrhizobia were present at the time of sampling. Prolonged storage in a frozen or severe drying condition completely destroyed the nodulating activity of the Bradyrhizobia and may have killed them; storage in a moist refrigerated state reduced their nondulating activity and may have adversely affected their survival.Key words: Glycine max (L.) Merrill, soybean, Bradyrhizobia nodulation, survival, freezing, drying


1973 ◽  
Vol 53 (3) ◽  
pp. 307-314 ◽  
Author(s):  
R. GROVER

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.


1986 ◽  
Vol 106 (3) ◽  
pp. 515-526 ◽  
Author(s):  
G. A. Rodgers ◽  
A. Penny ◽  
M. V. Hewitt

SummaryPrilled urea, with or without a nitrification inhibitor (dicyandiamide, DCD) or urease inhibitor (hydroquinone), was compared with ‘Nitro-Chalk’ as a nitrogen fertilizer for winter oil-seed rape in field experiments on a clay loam soil at Rothamsted in 1984 and 1985. Each was tested when supplying 50 kg N/ha to the seed bed; each was also broadcast in early spring to supply 150 kg N/ha as either a single dressing or two equal dressings, the form of nitrogen being the same as that applied in the seed bed.Seed-bed nitrogen increased plant growth during autumn and winter in both years but increased yield only in 1985.Scorching of plant leaves was severe in spring after application of urea or urea plus DCD given as a single dressing, but was much less with urea plus hydroquinone or when the dressings were divided. DCD inhibited nitrification of fertilizer nitrogen but had little effect on yield compared with urea alone. Ammonia volatilization losses were reduced by urea plus hydroquinone but, irrespective of the type of fertilizer applied, loss was always less than 3% of the nitrogen applied. Soil pH rose rapidly after urea application and thereafter fell slowly, whereas pH fell immediately after application of ‘Nitro-Chalk’. Neither dicyandiamide nor hydroquinone affected the pH changes after urea application. Overall, grain yields from urea were 90%, whereas those from urea plus hydroquinone were 97%, of those obtained from ‘Nitro-Chalk’. Dividing the spring dressings of urea-nitrogen increased yield in 1985 compared with a single dressing, but not in 1984. Yields from divided and single dressings of ‘Nitro-Chalk’ were similar. Oil and protein yields generally showed the same patterns of response to the fertilizer treatments as were shown by grain yields.


1978 ◽  
Vol 14 (3) ◽  
pp. 253-259 ◽  
Author(s):  
H. N. Verma ◽  
S. S. Prihar ◽  
Ranjodh Singh ◽  
Nathu Singh

SUMMARYField experiments were conducted for 4 years to study the yield of ‘kharif’ and ‘rabi’ crops grown in sequence on two soils differing in water-holding capacity. The results indicated that drought caused greater reduction in yield of rainy-season crops on loamy sand than on sandy loam soil. In low retentivity soil it was more profitable to raise a single crop of wheat on soil-stored water. In sandy loam soil of higher retentivity, two crops a year gave much higher yields than a single crop. Of the sequences tried, maize followed by wheat gave the highest and most stable yields. For ‘rabi’ crops, stored water showed a better yield response than an equivalent amount of rain during the growing season.


1983 ◽  
Vol 63 (2) ◽  
pp. 199-210 ◽  
Author(s):  
C. W. BULLEN ◽  
R. J. SOPER ◽  
L. D. BAILEY

Growth chamber and field experiments were conducted on Southern Manitoba soils, low in available soil phosphorus, to investigate the effects of various placement methods and levels of phosphorus fertilizer on soybean (Glycine max (L.) Merrill ’Maple Presto’). It was found that soybean responded well to applied phosphorus on low-P soil in growth chamber studies. In the first growth chamber experiment, P was applied in solution to 100%, 50%, 25%, 12.5% and 1% of the total soil volume. Dry matter yields, total phosphorus uptake and utilization of fertilizer P increased at each level of applied P as the size of the phosphated band was decreased. The results were partly attributed to greater chemical availability of P in the smaller zones of P fertilizer reaction. In a second growth chamber experiment, soybeans responded differently to phosphorus banded in six different locations. Placement of the fertilizer 2.5 cm directly below the seed was more effective in increasing dry matter yield, total phosphorus uptake and fertilizer P utilization than placement 2.5 cm and 5 cm away at the same depth or placement 5 cm below the seed, whether the band was directly below, 2.5 cm away or 5 cm away. Soybean yield responses in the field were greatest with P banded 2.5 cm directly below the seed on low-P soils. Placement of P 2.5 cm below the seed resulted in grain yields that were 64% and 50% higher (at the two sites) than those obtained in control plots. Sidebanding P, 2.5 cm below and 2.5 cm away from the seed at the same level of application, improved grain yields of control plots by 40% and 39%. Seed placement and broadcast applications of P were not as effective in increasing grain yields. Broadcasting P in fall or in spring at rates of up to 52.38 kg P/ha did not result in significantly higher grain yields than those obtained in control plots. Placement of P in contact with the seed appeared to reduce seedling emergence, resulting in depressed yields when 52.38 kg P/ha were applied. Key words: Glycine max L. Merrill, ’Maple Presto’


2013 ◽  
Vol 36 (10) ◽  
pp. 1871-1887 ◽  
Author(s):  
ALEXANDER STRIGENS ◽  
NICLAS M. FREITAG ◽  
XAVIER GILBERT ◽  
CHRISTOPH GRIEDER ◽  
CHRISTIAN RIEDELSHEIMER ◽  
...  

1987 ◽  
Vol 108 (2) ◽  
pp. 321-329 ◽  
Author(s):  
U. C. Sharma ◽  
B. R. Arora

SummarySix field experiments, three each during 1982–3 and 1983–4, were conducted on a sandy loam soil to study the effect of varying levels of nitrogen, phosphorus and potassium, in the absence and presence of farmyard manure (FYM) (30 t/ha), on the number of tubers and yield of potato in three grades. Increase in nitrogen, phosphorus and potassium application, in the absence or presence of FYM, did not significantly affect the total number of tubers/m2 but did affect the number of tubers in different grades. An increase in nitrogen and potassium significantly decreased the number of tubers/m2 in small (< 25 g) and increased in medium (25–75 g) and large (> 75 g) grades at 45, 60, 75 and 90 days after planting. Increase in the application of phosphorus increased the number of tubers/m2 in the small grade and decreased it in the large grade but did not affect the number in the medium grade. Increase in nitrogen and potassium application decreased the tuber yield in the small grade and increased it in the medium and large grades. Applied phosphorus increased the yield in the small and medium grades and decreased it in the large grade. The increase in the yield of tubers with increase in nitrogen and potassium application was found to be caused by an increase in the number of tubers in the medium and large grades at the expense of the small grade; however, with applied phosphorus the increase in yield was due to increase in the weight of individual tubers within the small and medium grades. FYM application decreased the number of tubers in the small grade and increased it in the medium and large grades. The response of potato to nitrogen increased and to phosphorus and potassium decreased with the application of FYM.


1979 ◽  
Vol 59 (4) ◽  
pp. 423-429 ◽  
Author(s):  
R. B. McKERCHER ◽  
W. R. McGREGOR

Applications of Ca to soil in both growth chamber and field experiments increased triallate [S-(2,3,3-trichloroallyl)-diisopropylthiocarbamate] activity. Ca appears to affect the distribution of triallate between the colloid and soil solution causing a shift of triallate toward the solution phase. These effects are measurable in pot experiments at Ca additions of about 1 meq/100 g soil or at field applications of 2.5 tonnes per hectare (1 ton per acre) of Ca(OH)2.


1991 ◽  
Vol 71 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. A. Bomke ◽  
L. E. Lowe

Field experiments evaluated yield response to deep-pit poultry manure application to barley on a clay soil near Prince George and a grass-legume forage on a silty clay loam soil near Chilliwack, B.C. Substantial dry matter yield increases were measured at manure applications up to 20 t ha−1. Subsamples of both crops and the poultry manure were analyzed for Cu, Zn, Mn, Ba, Pb, Ni, Cr, Cd, B and Co. Selenium analyses were made on selected crop samples. There were no indications of toxicity problems even at 40 t ha−1, the highest application. Copper and Zn concentrations in forages were increased by the poultry manure and the Mn/Cu ratio tended to decrease with manure application. Key words: Orchardgrass, ladino clover, barley, micronutrients


Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 636-641 ◽  
Author(s):  
Richard A. Beardmore ◽  
Dean L. Linscott

Two field experiments were conducted in 1984 and 1985 to determine the effects of fluazifop, haloxyfop, and sethoxydim on the suppression of water uptake and competition of wheat to seedling alfalfa. In all cases, suppression of wheat growth and stand led to significant reduction in soil water use. The amounts of conserved soil water significantly correlated with increased numbers of alfalfa plants; the correlation coefficients, respectively, for mid- and late-summer plantings were 0.47 and 0.41 in 1984 and 0.90 and 0.86 in 1985. Conservation of soil water was attributed to growth reduction or cessation of wheat growth by the herbicides and, to some extent, suppression of wheat leaf transpiration. All of the three herbicides would be effective in controlling volunteer wheat in a new alfalfa planting.


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