Assessment of the phosphorus and sulphur status of subterranean clover pastures. 3. Plant tests

1969 ◽  
Vol 9 (38) ◽  
pp. 329 ◽  
Author(s):  
D Bouma ◽  
K Spencer ◽  
EJ Dowling
Keyword(s):  
Leaf Area ◽  
Field Experiments ◽  
Correlation Coefficients ◽  
Subterranean Clover ◽  
Growing Season ◽  
Yield Response ◽  
Leaf Analysis ◽  
South Wales ◽  
Soluble Phosphorus ◽  
Yield Responses

Field experiments were carried out in south-eastern New South Wales to establish the relationships between three plant tests for phosphorus and for sulphur, and the yield responses of subterranean clover pastures to applied phosphorus and sulphur. Subterranean clover plants (CV. Mt. Barker), sampled early in the growing season of 1963 and on five occasions at approximately monthly intervals in 1964, were analysed for total and soluble phosphorus and for total and reducible sulphur. The third plant test involved a comparison of the leaf area responses measured seven days after transfer to appropriate nutrient solutions of clover plants sampled in the field plots at the beginning of each growing season. Correlation coefficients (R) varying from 0.546 to 0.908 were obtained for the curvilinear regression of relative yields on total phosphorus contents of the clover, but only under conditions of an adequate sulphur supply. The correlation coefficients for soluble phosphorus were generally lower and differed greatly between samplings. The correlation coefficients for the curvilinear regressions of yield responses on the total or reducible sulphur content of clover, under conditions of ample phosphorus supply, were never less than 0.606 at the end of the season, and for some of the earlier samplings were as high as 0.947. The correlation coefficients (r) between leaf area responses and yield responses to phosphorus were 0.576 and 0.716, and those for sulphur 0.710 and 0.692 in 1963 and 1964 respectively. In contrast to those based on leaf analysis, the relationships between leaf area responses and yield response for each one of the elements were not affected by the level of supply of the other element.

Soil and tissue tests to predict pasture yield responses to applications of potassium fertiliser in high-rainfall areas of south-western Australia

2002 ◽  
Vol 42 (2) ◽  
pp. 149 ◽  
Author(s):  
M. D. A. Bolland ◽  
W. J. Cox ◽  
B. J. Codling
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Relative Yield ◽  
Subterranean Clover ◽  
Test Method ◽  
Yield Response ◽  
Soil Test ◽  
Test Procedures ◽  
Pasture Production ◽  
Yield Responses

Dairy and beef pastures in the high (>800 mm annual average) rainfall areas of south-western Australia, based on subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum), grow on acidic to neutral deep (>40 cm) sands, up to 40 cm sand over loam or clay, or where loam or clay occur at the surface. Potassium deficiency is common, particularly for the sandy soils, requiring regular applications of fertiliser potassium for profitable pasture production. A large study was undertaken to assess 6 soil-test procedures, and tissue testing of dried herbage, as predictors of when fertiliser potassium was required for these pastures. The 100 field experiments, each conducted for 1 year, measured dried-herbage production separately for clover and ryegrass in response to applied fertiliser potassium (potassium chloride). Significant (P<0.05) increases in yield to applied potassium (yield response) were obtained in 42 experiments for clover and 6 experiments for ryegrass, indicating that grass roots were more able to access potassium from the soil than clover roots. When percentage of the maximum (relative) yield was related to soil-test potassium values for the top 10 cm of soil, the best relationships were obtained for the exchangeable (1 mol/L NH4Cl) and Colwell (0.5 mol/L NaHCO3-extracted) soil-test procedures for potassium. Both procedures accounted for about 42% of the variation for clover, 15% for ryegrass, and 32% for clover + grass. The Colwell procedure for the top 10 cm of soil is now the standard soil-test method for potassium used in Western Australia. No increases in clover yields to applied potassium were obtained for Colwell potassium at >100 mg/kg soil. There was always a clover-yield increase to applied potassium for Colwell potassium at <30 mg/kg soil. Corresponding potassium concentrations for ryegrass were >50 and <30 mg/kg soil. At potassium concentrations 30–100 mg/kg soil for clover and 30–50 mg/kg soil for ryegrass, the Colwell procedure did not reliably predict yield response, because from nil to large yield responses to applied potassium occurred. The Colwell procedure appears to extract the most labile potassium in the soil, including soluble potassium in soil solution and potassium balancing negative charge sites on soil constituents. In some soils, Colwell potassium was low indicating deficiency, yet plant roots may have accessed potassum deeper in the soil profile. Where the Colwell procedure does not reliably predict soil potassium status, tissue testing may help. The relationship between relative yield and tissue-test potassium varied markedly for different harvests in each year of the experiments, and for different experiments. For clover, the concentration of potassium in dried herbage that was related to 90% of the maximum, potassium non-limiting yield (critical potassium) was at the concentration of about 15 g/kg dried herbage for plants up to 8 weeks old, and at <10 g/kg dried herbage for plants older than 10–12 weeks. For ryegrass, there were insufficient data to provide reliable estimates of critical potassium.

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.

Response of annual pastures to applications of limestone in the high rainfall areas of south-western Australia

2002 ◽  
Vol 42 (7) ◽  
pp. 925 ◽  
Author(s):  
M. D. A. Bolland ◽  
D. G. Allen ◽  
Z. Rengel
Keyword(s):  
Soil Ph ◽  
Western Australia ◽  
Field Experiments ◽  
Sandy Loam ◽  
Subterranean Clover ◽  
Italian Ryegrass ◽  
Yield Response ◽  
Pasture Production ◽  
High Rainfall ◽  
Yield Responses

The yield response of long-term pastures growing on acidified soil to applications of limestone (0, 2.5, 5.0, 7.5 and 10.0 t/ha with adequate magnesium fertiliser, and 0 and 5 t/ha with no magnesium fertiliser) was measured in 5 field experiments on different representative soils of the high rainfall areas of south-western Australia. After application, limestone was incorporated 1 cm deep in 3 experiments, 3 cm deep in 1 experiment, and 7 cm in another experiment. The pastures comprised subterranean clover (Trifolium subterraneum), and annual and Italian ryegrass (Lolium rigidum and L. multiflorum), the dominant species found in intensively grazed dairy and beef pastures of the region. Yields were measured when ryegrass plants had 3 leaves per tiller, which is when pastures in the region are grazed to maximise utilisation by cattle.Subsoil acidity was a problem at 4 of the 5 sites, and was so severe at 1 site that, despite having the lowest soil pH to 50 cm depth, there was no yield response to limestone incorporated to 3 cm deep. Applications of fertiliser magnesium had no significant effect on pasture production, soil pH, aluminium and manganese, or concentration of magnesium in dried herbage in any of the 5 experiments. Increasing amounts of limestone consistently: (i) increased soil pH, by between 1–2 pH units in the top 5 cm of soil, and 0.5–1.0 of a pH unit in the 5–10 cm soil profile; and (ii) decreased, by up to 84–98%, the amount of exchangeable aluminium in the 0–5 and 5–10 cm soil profiles. During 3 years (1998–2000) there were: (i) no yield responses to limestone for a total of 9 assessments on a sand, or 11 assessments on a sandy gravel; (ii) 2 significant (P<0.05) yield responses to limestone, from a total of 8 assessments on a loamy clay and from 9 assessments on a loam; (iii) 9 significant yield responses from a total of 13 assessments on a sandy loam (2 from 5 assessments in 1998, 3 from 4 assessments in 1999, and all 4 assessments in 2000). The sandy loam had the largest amount of exchangeable aluminium in the top 5 cm of soil [about 1.6 cmol(+)/kg, accounting for 35% of the exchangeable cations]. Increasing limestone applications did not induce deficiency or toxicity of any nutrient elements in subterranean clover or ryegrass dried herbage and, for dried herbage of bulk samples of both species, had no effect on dry matter digestibility, metabolisable energy and concentration of crude protein.

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.

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.

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.

scholarly journals Differences in growth and yield responses to Aphis gossypii Glover between different okra varieties

2008 ◽  
Vol 43 (No. 3) ◽  
pp. 109-117 ◽  
Author(s):  
H.K. Shannag ◽  
J.M. Al-Qudah ◽  
I.M. Makhadmeh ◽  
N.M. Freihat
Keyword(s):  
Leaf Area ◽  
Aphis Gossypii ◽  
Total Yield ◽  
Dry Weight ◽  
Growing Season ◽  
Growth And Yield ◽  
Experimental Plant ◽  
Local Reduction ◽  
Yield Responses ◽  
Aphid Populations

The reactions of five commercial varieties of okra, <i>Abelmoschus esculentus</i>, to <i>A. gossypii</i> were evaluated under semiarid field conditions. Each experimental plant of varieties Clemson spineless, Clemson spineless 80, Lee, Perkins dwarf, and Local was infested 60 days after emergence by three late-nymphal instars of the aphid. The results showed that aphid populations increased constantly on the varieties, except for days 42 and 49 after infestation, attaining a peak at about the end of the growing season. Differences in aphid densities were recorded between varieties. The aphids were most numerous on var. Local, while lowest in number on var. Lee. Infestation by aphids on okra varieties reduced yield by 57% on var. Perkins dwarf, 56% on var. Lee, 24% on var. Clemson spineless, 21% on var. Clemson spineless 80, and 5% on var. Local. Reduction in the number of pods produced per plant followed the same pattern as observed for total yield. Aphids had not altered significantly the vegetative plant growth at day 37 following infestation. At day 66, a substantial decrease in shoot fresh and dry weights and also leaf area was evident on var. Perkins dwarf while on var. Clemson spineless only the leaf area was significantly reduced. Moreover, aphid-free controls varied widely in their growth and productivity at the end of growing season. Varieties Clemson spineless and Clemson spineless 80 produced the highest total yield and pod numbers, var. Local the lowest. The varieties Perkins dwarf and Clemson spineless produced significantly higher shoot fresh and dry weight, as well as leaf area, than vars. Lee and Local.

Yield and protein responses to nitrogen, and nitrogen fertiliser requirements of grain sorghum, in relation to soil nitrate levels

1997 ◽  
Vol 48 (8) ◽  
pp. 1187 ◽  
Author(s):  
I. C. R. Holford ◽  
J. F. Holland ◽  
A. J. Good ◽  
C. Leckie
Keyword(s):  
Yield Response ◽  
N Recovery ◽  
Soil Nitrate ◽  
Soil N ◽  
Response Curves ◽  
The North ◽  
Nitrate N ◽  
South Wales ◽  
Yield Responses ◽  
Protein Response

Sorghum fertiliser experiments at 40 sites on the north-western slopes andplains of New South Wales demonstrated that many soils are severely deficientin nitrogen (N), but most yield responses to fertiliser N occurred on sites inthe southern part of the region. Grain yields responded to fertiliser in fewerthan half of the experiments but protein concentrations responded in about75%.There were 4 distinct types of protein response curve, and the type of curvewas related to the degree of N deficiency. In the most deficient experiments(mean protein 6·1% or less), response curves were convex to thex -axis or linear; at intermediate deficiency (mean protein7·2%), response curves were sigmoid; and at low deficiency (meanprotein 9·7%), response curves were Mitscherlich. Yield responsenever occurred where grain protein was >10%.Maximum grain yield responses and amounts of fertiliser N for maximum profit,estimated by fitting the Mitscherlich equation to response curves, weresignificantly correlated with soil nitrate N levels at various depths in thesouthern experiments, but not in the northern experiments. This difference inN responses appeared to be caused by lower rainfall and higher soil N in mostof the northern experiments. Nitrate-N levels in soils sampled to 15 or 30 cmdepth were better correlated with yield response ( r> 0·81) and fertiliser requirement (r >0·72) than N levels to deeper depths.There was little or no fertiliser N recovery in the grain in the northern experiments but substantial recovery in the south where it was generallygreater than recovery by wheat in earlier experiments in the same region.Fertiliser requirement in relation to soil nitrate-N levels was lower thanthat of these wheat experiments. This was attributed to mid-spring soilsampling for sorghum which underestimates the soil N available to the sorghum

The availability of potassium in some Tasmanian soils. II. Exhaustive cropping in relation to potassium reserves in the soil

1960 ◽  
Vol 11 (5) ◽  
pp. 774 ◽  
Author(s):  
CS Piper ◽  
Vries MPC de
Keyword(s):  
Sandy Loam ◽  
South Australia ◽  
Subterranean Clover ◽  
Yield Response ◽  
Exchangeable Potassium ◽  
Severe Deficiency ◽  
Intensively Managed ◽  
High Level ◽  
Yield Responses ◽  
Severe Leaf

Five soil samples from Fingal, Tas., representing Frodsley sandy loam of varying exchangeable potassium status, were subjected to exhaustive cropping in pots and the changes in their potassium status and that of the crops measured. Three of the samples represented an area carrying improved pastures while two were from a less intensively managed property. The results were contrasted with those from two soils from South Australia (Urrbrae loam and Seddon gravelly sandy loam). The progressive removal of potassium by cropping was determined by analysis of each crop and of the soil at the end of the experiment. Uptake and removal of potassium was greatest from the soils of highest exchangeable potassium status. Potassium applied to the soils was also rapidly taken up by the crops. For the Tasmanian soils, applications of potassium gave no responses in yield until the level of exchangeable potassium in the control pots fell to 0.10-0.15 m-equiv./100 g. The higher the initial level of exchangeable potassium, the greater the number of crops before a yield response to applied potassium was obtained. In contrast, yields were maintained at a high level on Urrbrae loam and, even in the fourth crop, applications of potassium gave only a barely significant response. From Frodsley and Seddon soils only small amounts of potassium were taken up from non-exchangeable sources. From Urrbrae loam, in the absence of applied potassium, slightly more than half of the potassium taken up by the crops was derived from other than exchangeable sources. These differences were in keeping with the different amounts of potassium released to boiling nitric acid by these soils. After four crops exchangeable potassium was reduced to very low levels (0.05-0.14 m-equiv./100 g) in all five Tasmanian soils. These values were directly related to the amounts of difficultly exchangeable potassium in these soils. Exchangeable potassium in Urrbrae loam was not reduced below 0.33 m-equiv./100 g, again reflecting the higher reserve of difficultly exchangeable potassium in the illitic clay of this soil and its greater capacity to replenish the exchangeable potassium fraction. The percentage of potassium in the dry matter of the crop was closely related to the level of exchangeable potassium or exchangeable plus added potassium in the soil. Subterranean clover showing severe leaf necrosis due to potassium deficiency contained 0.55-0.63 per cent. potassium. Plants showing less severe deficiency symptoms or symptoms developing at a later stage showed 0.84-0.98 per cent. potassium. Plants with 1.20 per cent. potassium were free from symptoms and gave no further yield responses to applied potassium. Additions of potassium to the soil led to higher values in the plants, and luxury uptake was common. At least 84-95 per cent. of the applied potassium was taken up by the crops on four of the Tasmanian soils.

Recovery of fertiliser nitrogen in wheat grain and its implications for economic fertiliser use

1992 ◽  
Vol 32 (3) ◽  
pp. 383 ◽  
Author(s):  
AD Doyle ◽  
CC Leckie
Keyword(s):  
Grain Yield ◽  
Grain Protein Content ◽  
Yield Response ◽  
Grain Protein ◽  
N Recovery ◽  
N Application ◽  
Protein Levels ◽  
South Wales ◽  
Fertiliser Use ◽  
Yield Responses

Grain yield, protein, and nitrogen uptake responses are reported for 6 wheat fertiliser experiments in northern New South Wales which were representative of sites that were highly responsive, moderately responsive, and non-responsive to nitrogen (N) fertiliser applied at sowing. Apparent recoveries of applied N of 33-57% in the grain were recorded where grain yield was steeply increasing in response to additional applied N. Where yield increases were smaller in response to increments of N fertiliser, N recovery was 22-3096, but where further N application increased grain protein content but not grain yield, apparent recovery of additional fertiliser N fell below 20%. Apparent recovery was less than 10% in experiments where there was no yield response to N fertiliser. The implications for fertiliser recommendations are discussed relative to potential premium payment for wheat protein levels. It was concluded that established premium payments are too low to make N application an economic proposition to increase grain protein levels in the absence of grain yield responses.

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