Prediction of response to sulfur by established Siratro/grass pastures in south-eastern Queensland

1983 ◽  
Vol 23 (122) ◽  
pp. 280 ◽  
Author(s):  
GE Rayment
Keyword(s):  
Field Experiments ◽  
Laboratory Data ◽  
Model Fitting ◽  
Prediction Of Response ◽  
South Eastern ◽  
Critical Range ◽  
Plant Chemical ◽  
Diagnostic Samples ◽  
Macroptilium Atropurpureum ◽  
Sulfur Yield

Dry matter responses by component species of 18 established, commercial Macroptilium atropurpureum cv. Siratrolgrass pastures to gypsum topdressing treatments (0 or 25 kg S/ha) were assessed from field experiments conducted over a four-year period in south-eastern Oueensland under rain-grown conditions. The objective was to establish diagnostic criteria for the assessment of sulfur status by relating pasture yields to agronomic attributes and soil and plant chemical tests. Beneficial responses to gypsum were small (maximum of 32% in Siratro) and restricted to fewer than 25% of sites, whereas at disadvantaged sites (28% of total), grass yields were more severely depressed than Siratro yields. It was not possible to predict these effects from past sulfur fertilizer history, Siratro percentage in the pasture, or pasture age. Significant correlations between Siratro relative yields (100 x yield without sulfur/yield with sulfur applied, attenuated at 100 for model fitting) and both soil sulfate and plant sulfur concentrations confirmed the predictive value of these laboratory data. For Siratro, best prediction of responsiveness was provided by sulfur concentrations in either whole tops (R2 = 0.65) or diagnostic samples (tips of runners back to the fifth to sixth fully expanded leaf; R2 = 0.65). Critical value for diagnostic samples was 0. 16% S while for whole tops of Siratro the value varied with mathematical model from 0.13 to 0. 15% S. Phosphate-extractable sulfate was the most effective soil test but irrespective of sampling depth, it accounted for less than 50% of the variation in Siratro relative yields. Whether sampled at 0- 10 cm or 0-90 cm, a critical range of 3-5 ppm phosphate-extractable sulfate was indicated for the Siratro component. Grass and total pasture relative yields were not correlated with the chemical tests employed.

Effect of topdressed phosphorus fertilizer on established white clover based pastures in south-east Queensland. 2. Macronutrient status and prediction of yield responses using plant chemical tests

1979 ◽  
Vol 19 (99) ◽  
pp. 463 ◽  
Author(s):  
GE Rayment ◽  
RC Bruce
Keyword(s):  
White Clover ◽  
Field Experiments ◽  
Early Summer ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
Pasture Production ◽  
Plant Chemical ◽  
Diagnostic Samples ◽  
Yield Responses ◽  
Term Field

Details are given on the effect of topdressed phosphorus, at rates up to 60 kg P ha-1, on macronutrient concentrations and phosphorus uptakes of components of white clover based pastures from phosphorus responsive and non-responsive sites. These data were obtained from 17 short-term field experiments conducted over a five year period in south-east Queensland. Plant indices for predicting yield responses to phosphorus by these pastures were derived from nutrient concentrations in tops and in 'diagnostic' samples of white clover collected during spring to early summer. Mathematical approaches used had little effect on critical values obtained. For white clover tops, which comprised fresh leaves, petioles and flowers, a critical phosphorus concentration of from 0.28 to 0.30% was established. Alternatively, an N : P ratio of 15 effectively separated responsive from non-responsive sites. The critical phosphorus concentration based on 'diagnostic' samples, which differed from tops in that flowers were excluded, was 0.30%. There was no practical difference between diagnostic indices based on white clover or total pasture production.

scholarly journals Seismic surveying and imaging at the laboratory scale: A framework to cross-validate experiments and simulations for a salt-body environment

Geophysics ◽  
2020 ◽  
Vol 85 (3) ◽  
pp. T123-T139
Author(s):  
Bence Solymosi ◽  
Nathalie Favretto-Cristini ◽  
Vadim Monteiller ◽  
Paul Cristini ◽  
Bjørn Ursin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Imaging Techniques ◽  
Laboratory Data ◽  
Seismic Exploration ◽  
Scale Model ◽  
Water Tank ◽  
Time Migration ◽  
Reduced Scale

Laboratory experiments have been recently reintroduced into the ideas-to-applications pipeline for geophysical applications. Benefiting from recent technological advances, we believe that in the coming years, laboratory experiments can play a major role in supporting field experiments and numerical modeling, to explore some of the current challenges of seismic imaging in terms of, for instance, acquisition design or benchmarking of new imaging techniques at a low cost and in an agile way. But having confidence in the quality and accuracy of the experimental data obtained in a complex configuration, which mimics at a reduced scale a real geologic environment, is an essential prerequisite. This requires a robust framework regardless of the configuration studied. Our goal is to provide a global overview of this framework in the context of offshore seismics. To illustrate it, a reduced-scale model is used to represent a 3D complex-shaped salt body buried in sedimentary layers with curved surfaces. Zero-offset and offset reflection data are collected in a water tank, using a conventional pulse-echo technique. Then, a cross-validation approach is applied, which allows us, through comparison between experimental data and the numerical simulation, to point out some necessary future improvements of the laboratory setup to increase the accuracy of the experimental data, and the limitations of the numerical implementation that must also be tackled. Due to this approach, a hierarchical list of points can be collected, to which particular attention should be paid to make laboratory experiments an efficient tool in seismic exploration. Finally, the quality of the complex reduced-scale model and the global framework is successfully validated by applying reverse time migration to the laboratory data.

The measurement time required for determining total NH3 losses after field application of slurries by trail hoses

2012 ◽  
Vol 151 (1) ◽  
pp. 34-43 ◽  
Author(s):  
K. NI ◽  
A. PACHOLSKI ◽  
D. GERICKE ◽  
H. KAGE
Keyword(s):  
Western Europe ◽  
Field Experiments ◽  
Model Fitting ◽  
Climatic Conditions ◽  
Field Application ◽  
Organic Fertilizers ◽  
Measurement Time ◽  
Linear Coefficient ◽  
Close Relationship ◽  
Time Required

SUMMARYMonitoring ammonia (NH3) emission is time consuming and requires specialized measurement equipment. The measurement time can be reduced if there is a close relationship between time and subsequent cumulated NH3 emission values. A statistical analysis was employed to study the relationship between cumulative NH3 emissions over varying time intervals and final NH3 loss after 3 days of measurement. A large number of multi-plot field experiments on NH3 loss after the application of animal and biogas slurries by trail hoses to crops in Northern Germany were carried out from 2007 to 2010. Based on data from 2007, measured using a passive sampler method, a linear empirical model was developed to calculate final cumulated NH3 loss from intermediate cumulated losses. Linear model fitting showed that cumulative NH3 losses after 24 h were significantly correlated with final cumulated NH3 losses, explaining more than 0·98 of its variation. The linear coefficient was 1·34, implying that c. 0·73 of final NH3 loss occurred within the first 24 h. Validation by datasets obtained from another year (2008), two additional measurement methods and another agro-region (marsh area, 2009/10) resulted in a close agreement of model predictions with measured data within the range of model uncertainty and data variation. The results underpin the feasibility of calculating final NH3 losses from cumulative losses during first 24 h after slurry application and can be used to simplify NH3 loss measurement after the application of liquid slurries in multi-plot field experiments. The slope of the linear relationship is only valid for liquid slurries and the environmental conditions of the present study, which are typical for many agro-regions in north-western Europe, and will have to be adapted for different climatic conditions. A time-efficient measurement of emissions from solid organic fertilizers might require a different time span.

Agronomic variation in Centrosema virginianum in relation to its use as a sub-tropical pasture plant

1977 ◽  
Vol 17 (86) ◽  
pp. 435 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Growing Season ◽  
North Coast ◽  
Tropical Pasture ◽  
Flowering Pattern ◽  
Seedling Regeneration ◽  
South Eastern ◽  
Herbage Yield ◽  
Macroptilium Atropurpureum ◽  
Potential Improvement ◽  
Pasture Plant

Nineteen accessions of Centrosema virginianum were grown in replicated short rows at four sites in south-eastern Queensland and one site on the wet tropical north coast, and some of their agronomic characteristics were observed and compared with those of Macroptilium atropurpureum cv. Siratro. Three sites were abandoned when the accessions grew poorly or died during the winter, although Siratro survived and grew vigorously. At the remaining sub-tropical sites the accessions persisted under weed-free conditions where seedling regeneration more than compensated for plant losses during the winter. In the second season at these sites, rows were cut for herbage yield assessment either every six weeks during the growing season or once at the end of the season. Treatments were continued for a third season at one site. In most respects Siratro was superior to all C. virginianum accessions. The accessions differed considerably in herbage yield, winter survival, seed production, seedling regeneration and leafiness, and differed slightly in leaf and stem digestibility. Many accessions flowered for very long periods in south-eastern Queensland, in contrast to the markedly bimodal flowering pattern of Siratro, but peak flowering dates of the accessions in the autumn differed by up to three months. Both C. virginianum and Siratro showed a reduction in percentage pod set during the middle of the growing season. Variation between accessions is discussed in relation to potential improvement of C. virginianum by plant breeding.

Response of soybeans to planting date in south-eastern Queensland. III.* Agronomic and physiological response of cultivars to planting arrangements

1977 ◽  
Vol 28 (1) ◽  
pp. 63 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth ◽  
VE Mungomery
Keyword(s):  
Field Experiments ◽  
Moisture Stress ◽  
Planting Date ◽  
Plant Population ◽  
High Density ◽  
Planting Dates ◽  
South Eastern ◽  
Population Interaction ◽  
Narrow Row ◽  
Seed Yields

Results from five field experiments, designed to evaluate the response of several soybean cultivars to planting arrangement, and conducted at two locations in south-eastern Queensland during 1967–1972, are reported. Response to planting arrangement varied depending on cultivar maturity type, planting date, and availability of moisture during growth. Averaged over cultivars and planting arrangements, seed yields for irrigated soybeans were highest for December plantings, and declined as planting was delayed. A cultivar x planting date interaction was apparent. For December planting dates, yields of all cultivars were generally highest in 50.8 cm rows. A cultivar x plant population interaction occurred, with yields of the later-maturing cultivars maximized at lower plant population levels than for the earlier cultivars. When the planting date was delayed beyond December, yields of all cultivars were maximized in narrow row-high density treatments. Yields of the narrow row-high density late plantings were equivalent to, and in the case of the late-maturing cultivars, greater than, the highest December yields. Wide row widths (101 .6 cm) were consistently lower-yielding, regardless of cultivar and planting date. Seed yields were reduced substantially by periods of severe moisture stress during growth. The relative performance of cultivars of differing phenology depended primarily on the coincidence of periods of severe stress with critical stages of development, viz. pod and seed development. In the environments involving periods of severe moisture stress, seed yields were maximized in row widths narrower than 50.8 cm, and at the lowest plant populations used (c. 95,000 plants per ha). Such treatments most closely approached low density-equidistant spacings in these studies.

POTATO YIELD, DEPENDING ON AGROTECHNICAL METHODS OF CULTIVATION

10.12737/2423 ◽  
2014 ◽  
Vol 8 (4) ◽  
pp. 143-145 ◽  
Author(s):  
Табаков ◽  
Aleksey Tabakov ◽  
Шашкаров ◽  
Leonid Shashkarov ◽  
Самаркина ◽  
...  
Keyword(s):  
Field Experiments ◽  
Positive Impact ◽  
Potato Yield ◽  
Potato Tubers ◽  
The South ◽  
South Eastern ◽  
Yield And Quality ◽  
Chuvash Republic ◽  
Different Doses

The article presents the results of field experiments on the effect of preplant soil techniques in combination with different doses of fertilizers and pesticides in the cultivation of potato of Impala variety on productivity in the Chuvash Republic, which is located in the south-eastern part of the Volga-Vyatka region. The positive impact of the studied factors on yield and quality of potato tubers was revealed.

Prediction of yield responses to phosphorus by established Greenleaf desmodium/grass pastures in south-east Queensland using chemical tests

1980 ◽  
Vol 20 (105) ◽  
pp. 477
Author(s):  
GE Rayment ◽  
RC Bruce ◽  
BG Cook
Keyword(s):  
Soil Phosphorus ◽  
Residual Variance ◽  
Total Soil ◽  
Plant Chemical ◽  
Diagnostic Samples ◽  
Total Soil Phosphorus ◽  
Independent Variable ◽  
Phosphorus Status ◽  
Yield Responses ◽  
Phosphorus Levels

Phosphorus topdressing experiments (rates to 60 kg P ha-1) on 18 commercial Desmodium intortum cv. Greenleaf/grass pastures were conducted over a 4-year period in south-east Queensland. The aim was to determine whether yield responses, which occurred only in the Greenleaf component at six sites, could be predicted using soil or plant chemical tests. Acid-(0.005 M H2SO4) and bicarbonate-(0.5 M NaHCO3) extractable tests of phosphorus status in 0-10 cm soil samples each explained about 60% of the variance in Greenleaf relative yields. The residual variance was not significantly reduced by the inclusion of terms for total soil nitrogen, total soil phosphorus, exchangeable calcium and pH into the independent variable. These empirical soil phosphorus tests had higher predictive value than plant tests based on phosphorus concentrations in tops and diagnostic samples of Greenleaf. With both acid- and bicarbonate-extractable phosphorus, yield responses are likely in the Greenleaf component when phosphorus levels in most soils are below 22 ppm. Above 29 ppm, no response would be expected

Nitrogen fertilizer responses of pasture grasses in south-eastern Queensland

1963 ◽  
Vol 3 (11) ◽  
pp. 290 ◽  
Author(s):  
EF Henzell
Keyword(s):  
Ammonium Sulphate ◽  
Field Experiments ◽  
Maximum Growth ◽  
Nitrogen Fertilizers ◽  
Nitrogen Recovery ◽  
Residual Effects ◽  
Rhodes Grass ◽  
South Eastern ◽  
Pasture Grasses ◽  
Chloris Gayana

The results are reported of field experiments with nitrogen-fertilized pasture grasses at Samford and D'Aguilar in south-eastern Queensland. The main findings were :- 1. Nitrogen applied as urea or ammonium sulphate increased the annual yield of dry matter under mowing from 1,000- 5,000 lb up to 10,000-20,000 lb an acre, and rates of fertilizer in excess of 400 lb of elemental nitrogen an acre a year were required ,for maximum grass yields during favourable seasons. 2. Ammonium sulphate, applied at rates up to 400 lb N/acre/year, had relatively little effect on the percentage of nitrogen in Rhodes grass (Chloris gayana Kunth.), Paspalum dilatatum Poir., and P. commersonii Lam., cut three times a year. Rates of urea above those required for maximum growth markedly increased the percentage nitrogen content of a Sorghum almum Parodi-blue couch (Digitaria didactyla Willd.) mixture. 3. In an experiment with Rhodes grass, P. dilatatum and P. commersonii, nitrogen recovery rose with increasing rates of ammonium sulphate. At 70 lb N/acre/year the average nitrogen recovery by Rhodes grass was 10 per cent; at 400 lb N/acre/year it was 47 per cent. 4. The residual effects of ammonium sulphate, measured on Rhodes grass during the growing season following two years of fertilization, were very small indeed. 5. Use of nitrogen fertilizers sometimes caused marked changes in the botanical composition of the sward.

Effect of stubble cover on the efficacy of some soil-incorporated herbicides

1985 ◽  
Vol 25 (4) ◽  
pp. 927
Author(s):  
RJ Bateman ◽  
SR Walker
Keyword(s):  
Weed Control ◽  
Analysis Of Variance ◽  
Treatment Effects ◽  
Field Experiments ◽  
South Eastern ◽  
Plant Soil ◽  
Conventional Methods ◽  
Linear Correlations

Three field experiments were conducted near Kingaroy in south-eastern Queensland to determine the effect of sorghum stubble on the efficacy of the pre-plant, soil-incorporated herbicides pendimethalin, trifluralin and vernolate. Herbicides were applied to three stubble ranges (1 1 to 36% cover) in experiment 1, to stubble levels of 10, 20, 30, 40, and 50% cover in experiment 2, and approximately 0, 25 and 50% in experiment 3. In experiment 3 the effectiveness of incorporation with stubble mulch machinery consisting of chisel plough with attached rod weeder was compared with that achieved by conventional incorporation methods of coronet tines with mounted harrows and offset discs followed by tines and harrows. Treatment effects were examined by analysis of variance and by linear correlations between stubble cover and herbicide efficacy. Good to excellent weed control was achieved by all herbicides at stubble levels up to 50% cover with incorporation by stubble mulch machinery. Trifluralin efficacy was aided by stubble cover in one experiment. Incorporation by stubble mulch machinery was at least as effective as conventional methods.

scholarly journals Enhancing Cucurbita pepo Growth, Productivity, and Fruit Quality using Bacilli Strains and Cyanobacteria Treatments

2021 ◽  
pp. 1-11
Author(s):  
Ashmawi Elsayed Ashmawi ◽  
Amira M El-Emshaty ◽  
Gehan Mohamed Salem ◽  
Mona Fekry Ghazal
Keyword(s):  
Vegetative Growth ◽  
Cucurbita Pepo ◽  
Field Experiments ◽  
Growth Parameters ◽  
Available Phosphorus ◽  
Growing Seasons ◽  
Plant Chemical ◽  
Chemical Content ◽  
Soil Rhizosphere ◽  
Chemical Contents

Two successful field experiments were carried out during 2020and 2021 growing seasons to evaluate the effect of bio fertilizers; Bacillus amyloliquifaciens (BA), Bacillus megaterium (BM) and cyanobacteria inoculation on the vegetative growth, growth parameters and plant chemical content of Cucurbita pepo (Squash) crop. The study of mixed inoculation with both Bacillus strains, and cyanobacteria was found to improve vegetative growth, plant chemical contents and positive microbial activity in the soil Rhizosphere in comparison to un-inoculated plants. Soil available nutrients (N and K) increased significantly with BA and BM combined with cyanobacteria while available phosphorus gave most increase with BM.

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