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.

The estimation of the phosphorus fertilizer requirements of wheat in southern New South Wales by soil analysis

1963 ◽  
Vol 3 (10) ◽  
pp. 190 ◽  
Author(s):  
JD Colwell
Keyword(s):  
Response Surface ◽  
Field Experiments ◽  
Soil Analysis ◽  
New South ◽  
New South Wales ◽  
Relative Yield ◽  
Available Phosphorus ◽  
Phosphorus Fertilizer ◽  
Absolute Increase ◽  
South Wales

The usefulness of five contrasting methods of soil analysis for estimating the phosphorus fertilizer requirements of wheat in southern New South Wales has been investigated, using yield data provided by 27 field experiments. Because the level of yield of wheat is strongly affected by seasonal environmental conditions poor correlations are obtained between soil analysis and absolute or relative yield of wheat, Much better and often significant correlations are obtained between soil analysis and the absolute increase in yield from fertilizer application. The best correlations were obtained with an 0.5M NaHCO3 extraction of soil phosphorus. A regression response surface calculated from these relationships provides a method for making direct estimates of fertilizer requirements for maximum economic return to farmers under average climatic conditions. The precision of these estimates is limited more by the flatness of the response surface and uncontrolled variation in the field data, than by inadequacies in the representation of available phosphorus by the NaHCO3 analysis.

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.

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.

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.

Effect of sowing rate on grain yield, kernel weight, and grain protein percentage of barley (Hordeum vulgare L.) in northern New South Wales

1992 ◽  
Vol 32 (4) ◽  
pp. 465 ◽  
Author(s):  
AD Doyle ◽  
RW Kingston
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Kernel Weight ◽  
Grain Protein ◽  
Hordeum Vulgare L ◽  
Protein Percentage ◽  
South Wales

The effect of sowing rate (10-110 kg/ha) on the grain yield of barley (Hordeum vulgare L.) was determined from a total of 20 field experiments conducted in northern New South Wales from 1983 to 1986. Effects of sowing rate on kernel weight and grain protein percentage were also determined from 12 experiments conducted in 1985 and 1986. Two barley varieties were tested each year. In all years fallow plus winter rainfall was equal to or greater than average. Grain yield increased with higher sowing rates in most experiments, with the response curve reaching a plateau above 60-70 kg/ha. For 13 of the 40 variety x year combinations, grain yield fell at the highest sowing rates. Only in an experiment where lodging increased substantially with higher sowing rates was there a reduction in yield at a sowing rate of 60 kg/ha. The average sowing rate for which 5 kg grain was produced per kg of seed sown was 63 kg/ha. Grain protein percentage usually fell, and kernel weight invariably fell, with increasing sowing rate. Increasing sowing rates from the normal commercial rate of 35 kg/ha to a rate of 60 kg/ha typically increased grain yields by 100-400 kg/ha, decreased kernel weight by 0.4-2.0 mg, and decreased grain protein by up to 0.5 percentage points. In no case was the grain weight reduced to below malting specifications. It was concluded that sowing rates for barley in northern New South Wales should be increased to about 60 kg/ha.

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.

Production of summer crops in northern New South Wales. I. Effects of tillage and double cropping on growth, grain and N yields of six crops

1992 ◽  
Vol 43 (1) ◽  
pp. 105 ◽  
Author(s):  
DF Herridge ◽  
JF Holland
Keyword(s):  
N2 Fixation ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Growth Yield ◽  
No Tillage ◽  
Tillage Practice ◽  
Grain Yields ◽  
Double Cropping ◽  
South Wales

The effects of tillage practice and double cropping on growth, yield and N economies of summer crops were examined in field experiments near Tamworth, northern New South Wales. Sorghum, sunflower, soybean, mungbean, cowpea and pigeon pea were sown into alkaline, black earth soils which contained either high (Site A, sown January 1983), moderate (Site B, sown December 1983), or low concentrations of nitrate (Site C, sown December 1984). During the previous winters, the land had been sown to wheat (double crop) or fallowed using cultivation or no-tillage practices. At Sites A and B, dry matter yields, averaged over all crops, were increased by 34 and 14% under no-tillage. Average increases in grain yields at the two sites were 22 and 11%. At Site C, tillage practice did not affect yields. Soybean showed the greatest responses to no-tillage. Increases in grain yields were 46, 15 and 18% for Sites A, B and C respectively. The least responsive legume was mungbean. Yields of sorghum were increased by 41% at Site A; responses at Sites B and C ranged between a 9% decrease and a 7% increase. With double cropping, grain yields were, on average, 18 (Site A), 81 (Site B) and 72% (Site C) of the yields in the cultivated (fallow) plots. However, when comparisons were made for the 12 month periods, i.e. wheat and summer crops v. fallow and summer crops, production was more than doubled at Site B and tripled at Site C, compared with the cultivated fallow. Significant in the responses to double cropping were the 192 (Site B) and 230 mm rainfalls (Site C) during November and December that replenished the soil profile with water to a depth of >0.75 m. Assessments of soybean N2 fixation using the ureide method indicated large effects of site and season on the proportion of plant N derived from N2 fixation (range, 0-0.83), on the amount of N2 fixed (range, 0-233 kg N ha-1) and on the N balance as a result of the cropping (range, -69 to +45 kg N ha-1).

Effect of sowing time and nitrogen on rice cultivars of differing growth duration in New South Wales. 1. Yield and yield components

1994 ◽  
Vol 34 (7) ◽  
pp. 933 ◽  
Author(s):  
RF Reinke ◽  
LG Lewin ◽  
RL Williams
Keyword(s):  
Short Duration ◽  
New South ◽  
New South Wales ◽  
Yield Potential ◽  
High Yield ◽  
Yield Response ◽  
Growth Duration ◽  
Sowing Time ◽  
South Wales ◽  
Long Duration

New South Wales rice crops commonly take >180 days from sowing to harvest, and a reduction in crop duration is sought to increase the efficiency of rice production. The response of rice cultivars of differing growth duration to sowing time and N application was examined across 2 growing seasons. The highest yields were obtained at early sowing dates in each season. In season 2, the maximum yield of the short-duration cultivar M101 was not significantly different to the long-duration cultivars Calrose, Pelde, and M7, with yields >12 t/ha. However, yield of cv. M101 was significantly less than the long-duration cultivars at an early sowing date in season 1. Analysis of yield components did not clearly indicate the reason for reduced yield of the short duration cultivar. Damage by birds and mice before harvest, exacerbated by early maturity, is a possible cause.Later sowing reduced yields of all cultivars, with the short-duration cultivar-least affected. Optimum N application decreased with delay in sowing. At early sowings there was a positive yield response to increasing N, whereas at the latest sowings in each season the N response was negative for all cultivars. Where the yield response to applied N was positive, the yield component most associated with yield was the number of florets per unit area (r = 0.55). Where the yield response was negative, yield reductions were primarily caused by a reduction in the proportion of filled grains (r = 0.83). Minimum temperatures during the reproductive stage of each cultivar explained only a small amount of the variation in percentage of filled grain. Low minimum temperatures during the reproductive stage were not the sole cause of the reduction in proportion of filled grains of late-sown, high-N plots. The high yield potential of short-duration cultivars in The high yield potential of short-duration cultivars in the New South Wales rice-growing area is clearly demonstrated, as is the value of such cultivars where late sowing is unavoidable.

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