Estimations of sampling intensities for the characterization of soil within experiment sites

1971 ◽  
Vol 11 (52) ◽  
pp. 541
Author(s):  
JD Colwell
Keyword(s):  
Soil Profile ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Chemical Properties ◽  
Soil Core ◽  
Core Samples ◽  
South Wales ◽  
Soil Groups

Estimates are made of the desirable number of soil core samples that should be taken from the sites of field experiments for the estimation of profile trends in chemical properties for between site comparisons. The estimates are made on the basis of the magnitude of within site variance relative to between site variance. Fewer samples are required when between site variance is high than when it is low. The data were obtained from the sites of experiments representing four great soil groups in southern New South Wales. The desirable number of samples varies amongst the soil groups, with the chemical properties and with depth down the soil profile. Estimates for mean profile trends and for the means of individual depth strata were similar, It is concluded that at least 9 to 12 core samples should be taken per site and preferably 29 to 40 to ensure reasonably safe estimates of profile trends in important chemical properties.

A statistical-chemical characterization of four great soil groups in Southern New South Wales based on orthogonal polynomials

Soil Research ◽  
1970 ◽  
Vol 8 (3) ◽  
pp. 221 ◽  
Author(s):  
JD Colwell
Keyword(s):  
Orthogonal Polynomials ◽  
New South ◽  
New South Wales ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Soil Classification ◽  
Statistical Procedures ◽  
South Wales ◽  
The Mean ◽  
Soil Groups

Statistical procedures are described for the characterization and comparison of profiles within soil classification units. Profile trends in a measured characteristic are represented by the coefficients of orthogonal polynomials in depth, and these coefficients are used as observations for standard statistical procedures. The mean of the respective coefficients provides estimates of the mean profiles for the classification units, and the variance-covariance matrix of the coefficients can be used to calculate the confidence intervals of these means. Differences between the mean profiles can be tested by analyses of variance. The variability of a range of chemical properties in the profiles of four Great Soil Groups, viz. yellow podzolic, red earth, red-brown earth, and grey clay, is described. The characterization is based on the analysis of profiles sampled from areas of about 0.4 ha chosen to represent cultivated examples of the groups in southern New South Wales. Variability of most soil properties is greater between these areas than within them, notable exceptions being exchangeable calcium and magnesium within the grey clay Group. This high localized variability is attributed to the gilgaied nature of this group in this region. Also variation between the soil groups is generally greater than within the groups. The differences seem, however, of limited importance from the point of view of soil fertility.

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.

Corrigendum - Frequency of annual species of Medicago on the major soil groups of the Mcquarie region of New South Wales

1960 ◽  
Vol 11 (5) ◽  
pp. 705
Author(s):  
WD Andrew ◽  
FW Hely
Keyword(s):  
New South ◽  
New South Wales ◽  
Salt Content ◽  
Acid Group ◽  
Soluble Salt ◽  
Annual Species ◽  
South Wales ◽  
Soil Groups ◽  
Soil Habitat ◽  
Poor Drainage

The frequency of eight annual species of Medicago was determined on 10 soil groups in a region climatically favourable for medics. They occurred on nine of these, the overall frequency being in the order M. minima (L.) Bart. > M. denticulata Willd. > M. laciniata (L.) Mill., M. praecox DC., M. tribuloides Desr., and M. orbicularis (L.) Bart. > M. arabica (L.) Huds. and M. confinis Koch. M. minima was more tolerant of variation of soil habitat than any other medic in the region. M. denticulata was most commonly found on the soils of high soluble salt content and showed the greatest tolerance of poor drainage conditions. M. laciniata occurred in greatest abundance on soils of the well-drained brown acid group. M. praecox was most commonly found on soils with a compact gravelly surface. M. tribuloides was recorded on five soil groups but was common only on the black earths. M. orbicularis was confined to the black earth and red loam soils. M. arabica was rarely found, being restricted to lower, fertile, well-drained parts of the landscape, and M. confinis occurred only occasionally and then in association with M. denticulata.

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.

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).

The urease activity in profiles of five great soil groups from northern New South Wales

1968 ◽  
Vol 28 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Margaret G. Myers ◽  
J. W. McGarity
Keyword(s):  
Urease Activity ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
Soil Groups

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.

Sign in / Sign up

Export Citation Format

Share Document