Influence of intensity/quantity characteristics of soil phosphorus tests on their relationships to phosphorus responsiveness of wheat under field conditions

Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 343 ◽  
Author(s):  
ICR Holford ◽  
AD Doyle
Keyword(s):  
New South ◽  
Soil Phosphorus ◽  
Critical Value ◽  
Nitrogen Fertilizers ◽  
Yield Response ◽  
Soil Tests ◽  
Intensity Parameter ◽  
South Wales ◽  
Highly Correlated ◽  
Yield Responses

Six soil phosphorus tests (lactate, Brayl, Bray2, neutral fluoride, Olsen and Colwell) were regressed against potassium chloride-soluble phosphorus (intensity) and isotopically exchangeable phosphorus (quantity) measured in 59 soils of the northern and central wheat belts of New South Wales. Wheat nutrition experiments on these soils during 1986-89 measured yield responses to phosphate and nitrogen fertilizers. Soil tests varied widely in their correlations with yield responsiveness to phosphate, with the lactate and Bray2 tests accounting for more than twice the variance accounted for by other soil tests. The intensity parameter was also highly correlated but the quantity parameter was not. All soil tests, except Bray1, were very highly correlated with the intensity parameter, so this relationship did not differentiate the relative efficacies of the soil tests. Soil tests were less correlated with the quantity parameter, but those soil tests (neutral fluoride, Olsen and Colwell) that were most highly correlated (r2 > 0.62) with this parameter were most weakly correlated (r2 < 0.29) with yield response. It was concluded therefore that exchangeable phosphorus is not a satisfactory measure of the quantity factor and that an effective soil test for wheat-growing soils will be highly correlated with intensity but not necessarily with exchangeable phosphorus. The critical value of the lactate test was the same (17 mg/kg) as in previous studies with wheat but was lower (14 mg/kg) in 1989 when very low in-crop rainfall occurred. With deeper sampling (15 cm rather than 10 cm) the lactate test was slightly less accurate and the critical value was lower (11 mg/kg).

Control of post-emergence damping off in vetch with Dexon

1968 ◽  
Vol 8 (35) ◽  
pp. 767
Author(s):  
RN Allen
Keyword(s):  
Root Rot ◽  
New South ◽  
Yield Response ◽  
Damping Off ◽  
Plant Vigour ◽  
Basal Stem Rot ◽  
Stages Of Growth ◽  
South Wales ◽  
Yield Responses ◽  
The Cost

Control of post-emergence damping-off, basal stem rot, and root rot of vetch (Vicia sativu) caused by Pythium debaryanum and other pythiaceous fungi, was obtained in a sod-sown field trial at Wollongbar, New South Wales, by applying the fungicide Dexon (R) (p-dimethylaminobenzenediazo sodium sulphonate) with the fertilizer in the furrow at sowing. Dexon improved plant establishment and survival, and increased plant vigour in the early stages of growth. Dry matter yield of vetch was increased from 206 lb an acre without Dexon, to 604 lb an acre with Dexon applied at 8 oz an acre (4.3 mg per row ft), with a corresponding reduction in the cost of fodder produced. Yield responses were also obtained at lower and higher rates, but at 64 oz an acre the Dexon was phytotoxic and no yield response was observed despite excellent disease control.

Assessment of the phosphorus and sulphur status of subterranean clover pastures. 2. Soil tests

1969 ◽  
Vol 9 (38) ◽  
pp. 320 ◽  
Author(s):  
K Spencer ◽  
D Bouma ◽  
DV Moye
Keyword(s):  
New South ◽  
Subterranean Clover ◽  
Soil Samples ◽  
Soil Test ◽  
Soil Tests ◽  
Test Procedures ◽  
Pasture Production ◽  
South Wales ◽  
Extractable P ◽  
Yield Responses

Values obtained by a number of established soil test procedures for phosphorus and sulphur were correlated with yield responses to addition of the relevant nutrient, by subterranean clover-based pastures at 21 sites in south-eastern New South Wales. Colwell's bicarbonate-soluble P and Bray's P, phosphorus values showed sufficiently close associations with response to added phosphorus to be useful for predictive purposes ; Bray's P, values generally gave smaller coefficients. In general, the pasture on soils testing less than 25 p.p.m. bicarbonate-extractable P in the surface three inches responded appreciably to applied phosphorus (relative yields were <85 per cent). The corresponding value for the Bray P, procedure was 10 p.p.m. P. Soil samples from 0-1, 0-3, and 3-6 inch depths gave similar correlations with response. The time of soil sampling did not affect the relationships but winter pasture production was not as closely related to soil test values as was spring production. By contrast, soil tests for sulphur were not reliable but some discrimination between soils could be made with a 500 p.p.m. phosphate extraction. Values from soil samples collected in the winter were less closely related to response than were values from samples collected in the autumn.

Effect of split nitrogen applications on the yield and protein content of dryland wheat in northern New South Wales

1991 ◽  
Vol 31 (1) ◽  
pp. 85 ◽  
Author(s):  
AD Doyle ◽  
RA Shapland
Keyword(s):  
Grain Yield ◽  
New South ◽  
N Uptake ◽  
New South Wales ◽  
Dry Weight ◽  
Yield Response ◽  
Equivalent Amount ◽  
N Application ◽  
South Wales ◽  
Yield Responses

Experiments were conducted with dryland wheat on a nitrogen (N) deficient site near Gunnedah, northern New South Wales, in 1987 and 1988 to compare post-sowing foliar applications of N with urea drilled between the rows at sowing. Post-sowing N was applied at tillering, booting or at both stages at rates of 20 or 40 kg N/ha while presowing applications ranged from 0-106 kg N/ha. Above ground dry weight and N uptake increased with increasing N application at sowing. Post-sowing N application increased dry weight and N uptake, with generally greater increases in N uptake than in dry weight. Dry weight and N uptake for post-sowing N application were invariably less than when an equivalent amount of N had been applied at sowing. Grain yield was increased by the application of up to 106 kg N/ha at sowing in 1987 and up to 80 kg N/ha in 1988 when a greater degree of moisture stress during grain filling restricted yield responses. Post-sowing N increased grain yield, but the yield response was lower than for the application of an equivalent amount of N at sowing. Grain yield responses were lower when N was applied at booting rather than tillering. Yield responses over the 2 years were 0.35-0.39 t/ha and 0.44-0.68 t/ha for 20 and 40 kg N/ha, respectively, applied at tillering and 0.26-0.4 t/ha and 0.26-0.48 t/ha for N application at booting. Post-sowing N application increased grain protein, with greater increases for booting than for tillering applications. There was an apparent recovery in the grain of 48-56% of N applied at sowing, but only 25-48% of N applied post-sowing.

Effects of rainfall variability on the efficacy of soil phosphate tests for wheat on semi-arid soils

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 201 ◽  
Author(s):  
ICR Holford ◽  
EJ Corbin ◽  
CL Mullen ◽  
J Bradley
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Critical Values ◽  
The Other ◽  
Yield Response ◽  
Soil Tests ◽  
Soil Phosphate ◽  
South Wales ◽  
Semi Arid

Yield response data from 92 phosphate/nitrogen field experiments were used to evaluate and calibrate eight soil phosphate tests (Bray1, Bray2, alkaline fluoride, Mehlich, Truog, lactate, Olsen and Colwell) on semi-arid wheat-growing soils of central New South Wales. The effects of some aspects of year-to-year variability in rainfall characteristics on the efficacy and critical values of soil tests were also investigated. The order of efficacy of the soil tests was similar to that on the central western slopes (57 experiments) and northern region (48 experiments) of New South Wales. Lactate was not only the most effective test, but it was the only test that had the same critical value (18 mg kg-1) for the three regions. The actual efficacy of most soil tests in this semi-arid region was lower; apparently because the year-to-year variability in the annual average rainfall was greater than in the other two regions. Some or all of the soil tests were significantly related to yield responsiveness in three of the five individual years (1966-70) of the experimental period. In the other two years, relationships were vitiated by either semi-drought conditions (1967) or late frosts (1969). In 1970, when rainfall conditions were most favourable to yield response, average response curvature was lower and soil test critical values were higher than in the other years.

The mobility and transformation of soil nitrogen and the relationships between soil and plant nitrogen and yield at different times following application of various nitrogen fertilizers to sweet corn

1992 ◽  
Vol 43 (7) ◽  
pp. 1643 ◽  
Author(s):  
AA Salardini ◽  
LA Sparrow ◽  
RJ Holloway
Keyword(s):  
Soil Nitrogen ◽  
Sweet Corn ◽  
Nitrogen Fertilizers ◽  
Yield Response ◽  
Strongly Correlated ◽  
Mineral N ◽  
N Application ◽  
Plant Nitrogen ◽  
Highly Correlated ◽  
Sampling Times

The concentration of NH4-N, NO3-N and their sum (mineral N) were monitored 12 times in 1 or 2 weekly intervals in the soil under a sweet corn crop. The samples were taken on the fertilizer band and to depths of 200, 400 and 600 mm. The NO3-N concentration of the sap expressed from the midrib of the leaf opposite and immediately above the primary cob (sap NO3-N) and that of midrib dry matter (midrib NO3-N) were determined weekly. Under the low rainfall and optimized irrigation of this trial the concentration of mineral N in soil to the depth of 400 mm or more was a good predictor of yield response to application of N at 10 of the 12 sampling times. The concentration of either NH4-N or NO3-N in the soil to any depth and the concentration of mineral N in the surface 200 mm correlated with the yield at only a few times of sampling. The concentration of mineral N in the top 200 mm of soil 1 or 2 weeks after top-dressing of N was highly correlated to yield. The concentration of sap NOS-N and midrib NO3-N decreased continuously until harvest. Both these concentrations were significantly correlated with the rates of basal and top-dressed N in most sampling times. These were also strongly correlated to yield 1 or 2 weeks after N top-dressing. Ammonium sulfate, ammonium nitrate and urea gave similar responses in sap NO3-N and midrib NO3-N and in soil nitrogen after 5 weeks when nitrification of fertilizer NH4-N was complete. These observations indicated that soil mineral N, sap NO3-N and midrib NO3-N all offer potential as techniques to predict the yield response of sweet corn to N application. The sap NO3-N test was simpler, quicker, cheaper and more consistent than other tests.

Soil measurements and wheat yield response to superphosphate in Victoria

1975 ◽  
Vol 15 (72) ◽  
pp. 93
Author(s):  
B Palmer ◽  
VF McClelland ◽  
R Jardine
Keyword(s):  
Wheat Yield ◽  
Geographic Location ◽  
Yield Response ◽  
Soil Test ◽  
Soil Tests ◽  
Yield Data ◽  
Chemical Measurements ◽  
Soil Measurements ◽  
Yield Responses ◽  
Available Phosphate

The relationships between soil tests for 'plant available' phosphate and wheat yield response to applied superphosphate were examined and the extent to which these relationships were modified by other soil measurements was determined. Soil samples and wheat yield data were obtained from experiments conducted in the Victorian wheat belt. The sites were grouped into four relatively uniform classes using soil pH measurement and geographic location. The soil test values differed widely and were accountable for by the soil characteristics measured. However, the overall and within group yield responses to applied superphosphate could not be accounted for in terms of either the soil test value or the associated chemical measurements. By inference, yield response was clearly dependent on factors other than those determining the results of soil tests.

The residual value of a sulphatic fertilizer applied to a basaltic soil

1963 ◽  
Vol 3 (10) ◽  
pp. 180 ◽  
Author(s):  
K Spencer
Keyword(s):  
New South ◽  
Calcium Sulphate ◽  
First Year ◽  
Residual Value ◽  
Potential Response ◽  
South Wales ◽  
Native Pasture ◽  
Second Year ◽  
Yield Responses ◽  
Willow Tree

Yield responses d a native pasture on a basaltic soil near Willow Tree, New South Wales, were measured in the second, fourth, and seventh years after the application of several rates of calcium sulphate in the first year. The value of the residues declined sharply at first and then more slowly. Fifty per cent of the potential response by the legumes (the responsive component of the pasture) was achieved by an application of 7lb of sulphur an acre in the first year ; residues from an application of 20 lb of sulphur an acre were required in the second year, and from 48 lb S of sulphur an acre in the fourth year, to obtain the equivalent responses. By the seventh year, effects were too small to allow the derivation of a comparable figure.

The effect of fertilizers and season on the yield and composition of wheat in southern New South Wales

1963 ◽  
Vol 3 (8) ◽  
pp. 51 ◽  
Author(s):  
JD Colwell
Keyword(s):  
Vegetative Growth ◽  
Field Experiments ◽  
Application Rate ◽  
Early Spring ◽  
Nitrogen Fertilizers ◽  
Yield Response ◽  
Nitrogen Levels ◽  
South Wales ◽  
Wide Range ◽  
Common Application

Twenty two fertilizer experiments with wheat were carried out over a wide range of soil and environmental seasonal conditions in southern N.S. W. The effects of phosphorus and nitrogen fertilizers on the yield and composition of wheat are described. Seasonal environmental effects were examined by comparing the relative response to fertilizers of vegetative growth in the early spring with the final response of the harvested grain. Grain yield response to fertilizers is commonly restricted by seasonal conditions. Overcorrection of the phosphorus or nitrogen deficiencies may cause excessive early vegetative growth which exhausts soil moisture reserves before grain development has been completed. Loss of grain yields through this phenomenon is described locally as haying off. The chief danger in this respect seems to be from excessive nitrogen levels in the soil following a clover pasture. Assessments of economically desirable fertilizer applications on the basis of field experiments can only be based on statistical averages of seasonal conditions in each locality. The trials indicate, however, that the common application rate of superphosphate to wheat is inadequate in this region and should be at least doubled.

Response of Inga rice to nitrogen fertilizer rate and timing in New South Wales

1982 ◽  
Vol 22 (115) ◽  
pp. 62 ◽  
Author(s):  
DP Heenan ◽  
LG Lewin
Keyword(s):  
Nitrogen Fertilizer ◽  
Agricultural Research ◽  
New South ◽  
New South Wales ◽  
Research Centre ◽  
Yield Response ◽  
Fertilizer Rate ◽  
South Wales ◽  
Panicle Number ◽  
Nitrogen Fertilizer Rate

Two experiments were done at the Yanco Agricultural Research Centre, New South Wales, in 1978-79 and 1979-80 to measure the response of long grain rice, cv. Inga, to rates of nitrogen applied at two different times. The highest yields were recorded when the nitrogen was applied at panicle initiation. Increasing the rate from 100 to 200 kg N/ha at panicle initiation had no effect on grain yield. When the nitrogen was applied earlier, just before permanent water, yields were highest at 50 kg N/ha and declined at the highest rates (150 and 200 kg N/ha). This negative yield response was mainly due to a drop in the percentage of filled florets, and occurred despite an increase in panicle number.

The assessment of available manganese and aluminium status in acid soils under subterranean clover pastures of various ages

1983 ◽  
Vol 23 (121) ◽  
pp. 192 ◽  
Author(s):  
SM Bromfield ◽  
RW Cumming ◽  
DJ David ◽  
CH Williams
Keyword(s):  
Ammonium Acetate ◽  
New South ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Exchange Capacity ◽  
Manganese Toxicity ◽  
Manganese Concentration ◽  
South Wales ◽  
Yield Responses ◽  
Practical Measure

Three methods of estimating available manganese and aluminium status in acid soils were compared on three groups of soils from the Pejar district near Goulburn, New South Wales in which differences in pH had been brought about by different periods under subterranean clover pasture. Managanese extracted by 0.01 M calcium chloride gave the best correlation with the manganese concentration in rape and subterranean clover grown in pot culture, and provided the best index of available manganese. Soil solution manganese was inferior to CaCl2-extractable manganese and was more difficult to determine. Extraction with neutral ammonium acetate was unsatisfactory because this reagent overestimated available forms of manganese in soils containing high levels of reactive manganese. Aluminium extracted by 0.01 M CaCl2 was well correlated with exchangeable aluminium and with percentage aluminium saturation of the effective cation exchange capacity. None of the three measures of aluminium status alone was an effective index for predicting lime response by rape on these soils because both manganese and aluminium status were involved in this response. These three parameters were equally effective in multiple regressions for yield responses of rape to lime. Because of its relative ease of determination, CaCl2 extraction is preferred as a practical measure of aluminium status. Aluminium interacted with and increased the toxic effects of manganese in rape. Thus CaCl2-extractable manganese alone only provided a satisfactory index of a 'critical' value for manganese toxicity in rape for soils low in available aluminium. Subterranean clover was only slightly affected by aluminium and manganese levels in these soils, and manganese toxicity symptoms were only observed on soils containing 50 ppm or more CaCl2-extractable manganese. Nodulation failure in pots occurred in all soils with pH below 5.2 (water) or below 4.3 in CaCl2, whereas nodulation was normal when these soils were treated with CaCO3 to raise the pH to 5.8-6.0 (water). With one exception nodulation appeared adequate at field sites from which soils showing nodulation failure in the glasshouse had been collected.

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