EFFECT OF TYPE, RATE AND INCORPORATION OF LIME AND OF NITROGEN FERTILIZER AND GYPSUM ON MOVEMENT OF LIME IN SOIL COLUMNS

1986 ◽  
Vol 66 (4) ◽  
pp. 757-762
Author(s):  
P. B. HOYT ◽  
B. G. DROUGHT ◽  
G. H. NEILSEN ◽  
E. HOGUE

Soil columns were used to study downward movement of calcite and dolomite applied at two rates on the soil surface or incorporated 0–5 cm deep in combinations with gypsum and surface-applied N fertilizer. The columns were irrigated with 800 mm of deionized water applied over 3 wk. Incorporation of the liming materials greatly accelerated their downward movement in soil. Calcite and dolomite were equally effective in raising soil pH at the lower depths. Neither gypsum nor fertilizer nor doubling the liming rate had much effect on lime movement. Key words: Lime movement, calcite, dolomite, gypsum

1991 ◽  
Vol 117 (2) ◽  
pp. 241-249 ◽  
Author(s):  
T. M. Addiscott ◽  
R. J. Darby

SUMMARYOptimum applications of N fertilizer, Nopt have been related successfully to the amount of mineral N in the soil, Nmin in some parts of Europe but not always in the UK. If there is a body of mineral N, QN, that ultimately lessens the need for N fertilizer, it will not remain constant in its amount or its position. Mineralization will add to QN, while the nitrate component of QN will be leached downwards.Also, part of QN will be taken up into the crop where it will continue to lessen the need for fertilizer N but will be safe from leaching. A computer model was used to simulate these processes for 23 experiments, covering five sites and five years, in which N opt had been estimated. From these simulations we derived trial values of QN that took account of mineral N to a series of depths on a series of dates. For each date we used the trial values to find the depth for which Nopt was best correlated with QN andassumed that this was the depth, dL, of the lower boundary of QN on that date. Thus dL was a collective value for all 23 experiments. The value of dLincreased throughout the winter and the spring and was very closely related to the cumulative average drainage through 0·5 m soil at Rothamsted. By 15 April, dL, was 1·66 m, a depth that was compatible with observations by others that winter wheat can remove mineral N to a depth of at least 1·5 m. We inferred two likely reasons why Nmin may fail as a predictor of Nopt in the UK: insufficient depth of sampling, and too wide a spread of sampling dates. The values of Nopt were shown to be related satisfactorily to the values of QN computed, without any measurements of mineral N, for appropriate depths on single dates.


1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling


1989 ◽  
Vol 69 (3) ◽  
pp. 711-714 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY

The half-life of metribuzin applied to a bare soil surface was calculated to be 3–7 d over four field tests. An artificial cover erected after application or a shallow incorporation increased the half-life of metribuzin approximately 2.5- to 3-fold. Leaching out of the 0- to 5-cm-deep sampling zone could not account for loss of metribuzin. It was concluded that metribuzin persistence may be affected by volatility and/or photodecomposition losses under field conditions, especially shortly after application. Key words: Metribuzin half-life, volatility, photodecomposition, row width


1992 ◽  
Vol 72 (4) ◽  
pp. 555-567 ◽  
Author(s):  
S. C. Sheppard ◽  
W. G. Evenden

The halide elements are environmentally important and share some common attributes. The heaviest, I, and the lighest, F, are quite toxic and are important industrial pollutants. They are also effectively retained in soils. The others, Cl and Br, can be accumulated to high concentrations in plants, are used in agriculture and are highly mobile in soils. This study investigated the behaviour of the halides in plots, outdoor lysimeters, and laboratory sorption and excised-root experiments. Sorption on soil was ordered as F > I > Br > Cl. Concentrations in plants were generally ordered as CI ≥ Br > > F ≥ I, the inverse of the sorption ordering, as expected. Older tissues, which were also closest to the soil surface, had higher concentrations, and sequestered tissues, such as corn kernels and cabbage heads, had lower concentrations. There was evidence of competitive interaction among the halides and with soil anions such as phosphate and sulfate. This competition reduced the toxicity of I and modified tissue concentrations of the halides, P and S. Another interesting interaction was an increase in Cl and I sorption on soil solids when there were elevated levels or the other halides. Overall, the study of the halides in combination enhanced our understanding of their individual behaviours. Key words: Fluoride, chloride, bromide, iodide, vegetable


1987 ◽  
Vol 38 (4) ◽  
pp. 681 ◽  
Author(s):  
AS Hodgson ◽  
DA MacLeod

Foliar-applied nitrogen (N) fertilizer was investigated as a means of ameliorating the damage to cotton of waterlogging associated with extended furrow irrigation of a cracking grey clay. Dissolved urea was applied at 0, 5, 10 and 20 kg N ha-1 to the cotton foliage one day before furrow irrigations lasting 4, 8, 16 and 32 h. Treatments were repeated at three crop irrigations. Storms following the first two irrigations delayed the recovery from waterlogging and reduced treatment differences. However, foliar-applied N significantly increased late square and green boll numbers after the third irrigation, and produced more open bolls and heavier lint yields than the control treatment at harvest. Lint yields increased by 2.8, 5.9, 8.4 and up to 10.5 kg ha-1 per kg of foliar N applied before irrigations lasting 4, 8, 16 and 32 h, respectively. From this interaction it was concluded that foliar-applied N ameliorated the effects of waterlogging. Nevertheless, in the most severe waterlogging treatment, yield response to foliar N reached a limit, indicating that some other factor had become limiting.


1985 ◽  
Vol 17 (10) ◽  
pp. 197-199 ◽  
Author(s):  
P. H. Jørgensen

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.


Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 719-722 ◽  
Author(s):  
J. J. Kells ◽  
R. L. Blevins ◽  
C. E. Rieck ◽  
W. M. Muir

Field studies were conducted to determine the effect of soil surface (upper 5 cm) pH and tillage on weed control and corn (Zea maysL.) yield using simazine [2-chloro-4,6-bis-(ethylamino)-s-triazine] as the herbicide for weed control. Soil pH, weed control, and corn yield were examined under no-tillage and conventional tillage systems with and without added lime and different rates of nitrogen. Increased soil pH significantly increased weed control as compared with added lime vs. no added lime, where the surface soil pH influenced the effectiveness of the applied simazine. Soil pH had a greater effect on weed control under no-tillage than under conventional tillage. Conventional tillage significantly (P<.01) increased weed control, yield, and soil pH over no-tillage. Additions of lime as compared to unlimed treatments resulted in significantly increased weed control (83% vs. 63%), yield (5,930 vs. 5,290 kg/ha) and soil pH (5.91 vs. 5.22). The poorest weed control was observed with no-tillage on unlimed plots. A significant tillage by linear effect of nitrogen interaction for all variables resulted from a greater decrease (P<.01) in weed control and soil pH and a greater increase in yield with increased nitrogen under no-tillage than with conventional tillage.


1992 ◽  
Vol 72 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Liangxue Liu ◽  
T. E. Bates ◽  
T. S. Tran

The extractions of soil K by electroultrafiltration (EUF) and by chemical methods were compared as predictors of plant-available K for greenhouse-grown alfalfa on 38 Ontario soils. The relation of soil properties to the amount of K extracted by EUF fractions was also examined. The contents of silt and clay were negatively correlated with EUF-K at 50 V and 22 °C and positively correlated with EUF-K at 400 V and 80 °C. Soil pH and organic matter were not significantly correlated with the amounts of K extracted in the EUF-K fractions. The EUF extraction of K was influenced by the presence of carbonate or high exchangeable calcium in soils. Similar correlations were obtained between K uptake and K extracted by chemical methods and the sum of EUF-K fractions. When used along with other soil properties, EUF-K fractions and K extracted by chemical methods predicted availability of soil K with roughly equal ability. The model using the sum of K extracted by EUF at 50, 200 and 400 V is the simplest one and contains three variables, K, K2 and Ca2. The use of EUF is limited due to cost of equipment and time required for analysis, unless a number of nutrients can be accurately determined on one extract. Among the chemical methods, equations developed using three nonacidic extradants, NaCl, ABDTPA and NH4OAc explained more variation in K uptake than two acidic extractants, Mehlich 3 and 0.1 M HNO3. The NaCl model, ABDTPA model and NH4OAc model contained the same variables and had similar R2 values (0.88–0.91). Key words: Available K, chemical methods, electro-ultrafiltration, EUF-K fractions, K uptake


1983 ◽  
Vol 63 (2) ◽  
pp. 401-403
Author(s):  
C. B. CHAMPTON

Colorimetric soil pH measurements made systematically across Burnaby Mountain in well-drained loamy soils of the rainforest of British Columbia over an 8-yr period from 1974 until 1981 showed that acidification of the subsoil increased after two consecutive drier-than-average years. This changing acidity contrasted with the relatively stable acidity of the subsoil in imperfectly drained soils, regardless of changing patterns of precipitation. Key words: pH, forests, loams, precipitation


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