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.

An evaluation of eight soil phosphate extractants on acidic wheat growing soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 647 ◽  
Author(s):  
ICR Holford ◽  
BR Cullis
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Critical Values ◽  
Alkaline Soils ◽  
Wheat Field ◽  
Extraction Procedures ◽  
Soil Phosphate ◽  
South Wales

In a study using earlier data from 44 wheat field experiments on acidic (pH < 5.6) soils in southern New South Wales, eight soil phosphate extractants (Bray,, Bray,, neutral fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. All extraction procedures, except Colwell, had a standard shaking time of 30 min and so1ution:soil ratio of 50. The order of efficacy of the tests was different from that obtained on moderately acid to alkaline soils of central and northern New South Wales. Neutral fluoride and acidic sulfate (Truog) replaced lactate as the best extractant, followed by the double acid Mehlich extractant. The Colwell test was more effective on these very acid soils than on the more alkaline soils, being equal to Bray1 and greatly superior to Bray2 and Olsen. The critical values of the fluoride, Mehlich, Truog, lactate and Colwell tests were significantly lower than they were for more alkaline soils in central New South Wales. The changes in extraction procedures could explain the lower critical values of the lactate and Truog tests, but differences in the critical values of the other three tests were inconsistent with changes in extraction procedures. The results support the hypothesis that a different phosphate extractant is required on very acid soils from that required on moderately acid to alkaline soils.

Efficacy of various soil phosphate tests for predicting phosphate responsiveness and requirements of clover pastures on acidic tableland soils

Soil Research ◽  
1988 ◽  
Vol 26 (3) ◽  
pp. 479 ◽  
Author(s):  
ICR Holford ◽  
GJ Crocker
Keyword(s):  
White Clover ◽  
Significant Positive Correlation ◽  
New South ◽  
Acid Soils ◽  
Critical Values ◽  
Yield Response ◽  
Acidic Soils ◽  
Soil Phosphate ◽  
South Wales ◽  
Fertilizer Requirement

The efficacies of six different soil phosphate tests (Bray1, Bray2, alkaline fluoride, lactate, Olsen and Colwell) for predicting yield responsiveness and phosphate requirements of white clover pastures were investigated in 41 experiments over five years on acidic soils of the Northern Tablelands of New South Wales. The results contrasted with those obtained on slightly acid-to-alkaline wheat-growing soils and supported the dual hypothesis that a different type of phosphate extractant is required on acidic pasture soils from that required on more alkaline wheat-growing soils, and that phosphate sorptivity is of little importance on more acid soils. The Bray1 test was the most effective, and the lactate test least effective, in predicting responsiveness and fertilizer requirement. All soil tests, except Bray2 and lactate, were more effective on these acidic soils than on more alkaline wheat-growing soils. This was partly caused by a significant positive correlation between values of the more effective tests and yield response curvatures. However, there was no correlation between phosphate sorption and response curvature. The critical values for Bray1, fluoride and bicarbonate tests were similar to those on wheat-growing soils, but those for Bray2 and lactate were somewhat higher. Critical values for the Colwell test tended to increase with increasing phosphate sorptivity.

The calibration, interpretation, and evaluation of tests for the phosphorus fertilizer requirements of wheat in Northern New South Wales

Soil Research ◽  
1968 ◽  
Vol 6 (1) ◽  
pp. 105 ◽  
Author(s):  
JD Colwell ◽  
RJ Esdaile
Keyword(s):  
Field Experiments ◽  
New South ◽  
General Procedure ◽  
New South Wales ◽  
Clay Content ◽  
Calibration Procedure ◽  
Yield Response ◽  
Phosphorus Fertilizer ◽  
South Wales ◽  
Soluble Phosphorus

A general procedure is described for the estimation of fertilizer requirements from measurements on all factors that affect plant response to fertilizer. Tests for fertilizer requirement are defined as all measurements of factors that affect the fertilizer requirements of a crop, and the calibration procedure is based on the prediction of yield response functions for particular sites from test measurements representing the sites. Several tests can be used simultaneously for the prediction of fertilizer requirements, and this is demonstrated by the calibration of the soil tests, NaHCO3-soluble phosphorus, NaHC03-soluble potassium, and pH, against yield response of wheat to phosphorus fertilizer using data from 49 field experiments in northern New South Wales. The value of rainfall and clay content as tests was also investigated but their contributions to the calibration equations were non-significant. The application of economic principles for the estimation of optimal phosphorus fertilizer requirements is demonstrated. Fertilizer requirements decrease with increase in the value of NaHCO3-soluble phosphorus, with increase in pH, and with decrease in NaHCO3-soluble potassium. A statistical and economic evaluation of the tests is made on the basis of the regression surfaces established under the calibration procedure, and it is concluded that the value of testing for phosphorus fertilizer requirements is considerable.

Agronomic studies on irrigated soybean in southern New South Wales. II. Broadening options for sowing date

2011 ◽  
Vol 62 (12) ◽  
pp. 1067 ◽  
Author(s):  
L. G. Gaynor ◽  
R. J. Lawn ◽  
A. T. James
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Plant Population ◽  
Yield Potential ◽  
Higher Plant ◽  
Winter Cereal ◽  
Double Cropping ◽  
South Wales

The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.

Yield and yield structure of triticales compared with wheat in northern New South Wales

1992 ◽  
Vol 32 (4) ◽  
pp. 447 ◽  
Author(s):  
G Sweeney ◽  
RS Jessop ◽  
H Harris
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Moisture Stress ◽  
Grain Number ◽  
Wheat Varieties ◽  
Development Patterns ◽  
South Wales ◽  
Yield Structure ◽  
1000 Grain Weight

The yields and yield structure of cultivars of triticales and bread wheats (with a range of phasic development patterns in both species) were compared in 2 field experiments at Narrabri in northern New South Wales. The experiments were performed on a grey cracking clay soil with irrigation to prevent severe moisture stress. Triticales, both early and midseason types, appeared to have reached yield parity with well-adapted wheat varieties. Meaned over the 2 experiments and all sowings, the triticales yields were 19% greater than the bread wheats. Triticales were generally superior to wheat in all components of yield of the spike (1000-grain weight, grain number/spikelet and spikelet number/spike), whilst the wheats produced more spikes per unit area. The triticales also had higher harvest indices than the wheats. The results are discussed in relation to the overall adaptability of triticale for Australian conditions.

Cereals for winter grazing on the Northern Tablelands of New South Wales

1974 ◽  
Vol 14 (71) ◽  
pp. 790 ◽  
Author(s):  
JV Lovett ◽  
EM Matheson
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Single Species ◽  
Winter Period ◽  
In Vitro Digestibility ◽  
Forage Production ◽  
Species Response ◽  
South Wales

In field experiments conducted over three years at Armidale, New South Wales, the total winter forage production by barley, oats, wheat and rye was similar. However, barley and rye tended to outyield wheat and oats at early harvests, the reverse applying at late harvests. It is suggested that these characteristics of the cereals could be exploited to meet specific seasonal requirements for dry matter production more effectively than is possible with a single species. Response to high seeding rates in forage production was similar in all cereals and was confined to a late sowing. Significant differences in in vitro digestibility over the winter period were recorded and differences were also apparent in subsequent grain yield.

Resistance of some Australian inbred maize lines to maize dwarf mosaic disease

1969 ◽  
Vol 9 (40) ◽  
pp. 541 ◽  
Author(s):  
PW Grogan ◽  
DS Teakle
Keyword(s):  
New South ◽  
Natural Infection ◽  
New South Wales ◽  
Inbred Lines ◽  
Mosaic Disease ◽  
The Other ◽  
Maize Inbred Lines ◽  
South Wales ◽  
Resistant Lines

Seven out of eight maize inbred lines developed at Lawes in Queensland from open-pollinated varieties were resistant to maize dwarf mosaic disease when exposed to natural infection in the field. Five of the seven resistant inbred lines failed to become systemically infected when inoculated with infectious sap in the glasshouse. By contrast, only three out of twenty lines introduced from the U.S.A., and two out of eight lines developed at the Grafton and Glen Innes Breeding Stations in New South Wales, were resistant in the field. All three resistant lines from the U.S.A. were systemically infected when inoculated in the glasshouse, but the two resistant lines from Grafton in New South Wales were not. The resistant Lawes and Grafton maize inbred lines would appear to be better sources of genes conferring resistance to maize dwarf mosaic disease than the other lines tested.

Effect of prolonged undernutrition on the recovery and reproductive performance of maiden Merino ewes

1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
First Year ◽  
Treatment Groups ◽  
South Wales ◽  
Feeding Trials ◽  
The Mean

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.

The effect of sowing rate on the yield and composition of wheat grown on soils of high fertility in southern New South Wales

1963 ◽  
Vol 3 (9) ◽  
pp. 114 ◽  
Author(s):  
JD Colwell
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Maximum Yield ◽  
Moisture Stress ◽  
High Fertility ◽  
Seeding Rate ◽  
Fertilizer Response ◽  
South Wales ◽  
Wide Range

The effects of the different sowing rates of 20, 40, and 60 lb of seed an acre on the yield, bushel weight, composition, and response to fertilizers, of wheat grown on soils of high fertility has been studied in seven field experiments in the wheat-belt of southern New South Wales. Seasonal conditions ranged from drought to lush growing conditions and in addition one experiment was irrigated to reduce the effects of moisture stress on plant growth. Yields ranged from 10 to 70 bushels of wheat an acre and fertilizer treatments gave both positive and negative effects. For the wide range of growth conditions, variation in seeding rate had only small and non-significant effects on grain yields, with the exception of the irrigated experiment where a consistent trend indicated the need for higher seeding rates for maximum yield. Effects of the seeding rates on grain size and composition and fertilizer response, were negligible. Losses in potential grain yield, caused by the exhaustion of soil moisture reserves by excessive vegetative growth of high fertility soils before grain development has been completed, does not seem to be reduced appreciably by the use of low seeding rates.

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