Superphosphate on wheat: The cumulative effect of repeated applications on yield response

1968 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
VF McClelland
Keyword(s):  
Wheat Yield ◽  
Cumulative Effect ◽  
Cumulative Effects ◽  
Residual Effects ◽  
Yield Response ◽  
Experimental Site ◽  
Growing Period ◽  
Rotation System ◽  
Repeated Applications ◽  
Yield Responses

The cumulative effects of repeated applications of superphosphate on wheat yield responses, over a period of 26 years (10 cycles of a rotation system), were examined. Since cumulative effects are the sum of current and residual effects and current effects diminish with repeated applications of superphosphate, this approach enabled residual effects to be inferred. Residual effects were apparent at all rates of application (30, 60, 90, and 120 lb/acre), being greater at the three higher levels. The influence of rainfall in the growing period (April to October) on cumulative effects was also examined. April rainfall increased yield at all levels of application, whereas September rainfall increased yield only at 90 and 120 lb/acre of superphosphate. The results indicate that, for this particular experimental site, residual phosphorus has become more important in determining yield responses than currently applied phosphorus.

Soil measurements and wheat yield response to superphosphate in Victoria

1975 ◽  
Vol 15 (72) ◽  
pp. 93
Author(s):  
B Palmer ◽  
VF McClelland ◽  
R Jardine
Keyword(s):  
Wheat Yield ◽  
Geographic Location ◽  
Yield Response ◽  
Soil Test ◽  
Soil Tests ◽  
Yield Data ◽  
Chemical Measurements ◽  
Soil Measurements ◽  
Yield Responses ◽  
Available Phosphate

The relationships between soil tests for 'plant available' phosphate and wheat yield response to applied superphosphate were examined and the extent to which these relationships were modified by other soil measurements was determined. Soil samples and wheat yield data were obtained from experiments conducted in the Victorian wheat belt. The sites were grouped into four relatively uniform classes using soil pH measurement and geographic location. The soil test values differed widely and were accountable for by the soil characteristics measured. However, the overall and within group yield responses to applied superphosphate could not be accounted for in terms of either the soil test value or the associated chemical measurements. By inference, yield response was clearly dependent on factors other than those determining the results of soil tests.

Effect of nitrogen fertilizer residues on the response of irrigated bromegrass to fertilizer nitrogen

1995 ◽  
Vol 75 (2) ◽  
pp. 381-386
Author(s):  
A. J. Leyshon ◽  
C. A. Campbell
Keyword(s):  
N Fertilizer ◽  
Forage Yield ◽  
Residual Effects ◽  
Organic N ◽  
Yield Response ◽  
Fertilizer N ◽  
Response Curves ◽  
Yield Responses ◽  
Moisture Conditions ◽  
N Rates

Two nitrogen (N) fertilizer response trials were superimposed, in 2 consecutive years, on a set of large plots of irrigated bromegrass (Bromus inermis Leyss.) that had been fertilized with different rates of fertilizer N up to 200 kg ha−1 for the previous 9 and 10 yr, respectively. During those years, forage dry matter responded in direct proportion to fertilizer N rate. In the subsequent two trials we determined the residual effects of the prior fertilizer treatments on the response of bromegrass to new applications of N fertilizer, and the N rate required to achieve maximum yields. The yield response of the bromegrass to the applied N was a function of prior fertilizer history and the moisture conditions. In the first trial, under good moisture conditions, the previously unfertilized plots had maximum yields at a N rate of 382 kg N ha−1; yields declined at higher rates. Responses of previously fertilized plots to additional N were linear. The y-intercepts (where no N was applied) were higher for plots that had been fertilized at higher N rates in the initial 9-yr study while the slopes of the yield responses were less steep. In contrast, in the second trial, conducted in a year when irrigation water was restricted, all forage yield responses to N fertilizer were curvilinear, Y-intercepts were again higher on plots that had been fertilized at higher N rates in previous years. In this case, however, the slopes of the N responses became progressively steeper with increasing N rate while increasingly larger quadratic coefficients resulted in maximum yields being attained at progressively lower N rates. Nevertheless, maximum yields were higher than those of the previously unfertilized plots. Changes in the response curves were attributed to alterations in the soil organic N and to a lesser extent, to changes in the capability of the bromegrass to respond to fertilizer N. Soil tests found no carry-over of fertilizer N as residual inorganic N but the initial potential rate of mineralization (N0k) reflected changes in the quality of soil organic matter influencing the response to N fertilizer applications. The results suggest the need for soil testing laboratories to take into account the prior fertilizer history of the grass stand when developing recommended N fertilizer rates for irrigated bromegrass. Key words: Bromegrass, N fertilization, residual N, mineralizable N

A review of trends in wheat yield responses to conservation cropping in Australia

1995 ◽  
Vol 35 (7) ◽  
pp. 835 ◽  
Author(s):  
JA Kirkegaard
Keyword(s):  
Wheat Yield ◽  
Farming Systems ◽  
Yield Response ◽  
Soil Conditions ◽  
Stubble Retention ◽  
Conservation Farming ◽  
Rhizoctonia Root Rot ◽  
Using Data ◽  
Yield Responses

Trends in wheat yield responses to conservation cropping in Australia were analysed using data from 33 medium-term (3-5 year) and long-term (>5 year) agronomic experiments. The overall effect of tillage (direct drilled v. cultivated) was small in all regions (-0.18 to +0.06 t/ha), while stubble retention (stubble retained v. stubble burnt) reduced yield in all regions (-0.31 to -0.02 t/ha). There was large year-to-year variation in the yield response to both tillage and stubble retention at all sites, but no consistent relationship between yield variation and amount or pattern of seasonal rainfall based on monthly totals. There was also little evidence that the yield of direct-drilled and stubble-retained treatments increased relative to cultivated or stubble-burnt treatments with the duration of the experiments, despite the improvement in soil conditions reported at many sites. The factors thought responsible for the year-toyear variation in yield response varied within and between regions, although some consistent effects emerged. Reduced early seedling growth of directdrilled crops was considered a major factor underlying the yield response at most sites, and this was rarely associated with the availability of water or nitrogen. High soil strength and increased severity of rhizoctonia root rot were responsible for these effects at some sites, but at others the cause remains unclear. Stubble retention influenced yield in many ways but the significance of the allelopathic effects of stubble, suspected by many authors to influence crop growth, is poorly understood. Adoption of direct drilling and stubble retention is likely to remain low in areas where no long-term yield benefit can be demonstrated and where greater management flexibility is offered by systems of reduced cultivation and late stubble burning-incorporation. Further research should identify and develop strategies to overcome the constraints to yield in conservation farming systems, particularly stubble retention, and assess the sustainability of recent innovations incorporating minimum disturbance and partial stubble retention. The more rapid adoption of such intermediate strategies will hasten the move of the grains industry toward sustainable production.

The effect of repeated applications of phosphorus fertiliser on wheat yields in the Mallee from 1943 to 2006

2008 ◽  
Vol 59 (8) ◽  
pp. 742 ◽  
Author(s):  
R. A. Latta ◽  
I. Mock ◽  
J. Smith
Keyword(s):  
Growing Season ◽  
Cumulative Effects ◽  
Residual Effects ◽  
Residual P ◽  
Grain Yields ◽  
Term Experiment ◽  
Phosphorus Fertiliser ◽  
Long Term Experiment ◽  
Repeated Applications

A previous study in 1968 on this long-term experiment reported the cumulative effects of repeated applications of phosphorus (P) and found that residual effects of applied P resulted in increasing grain yields. A re-analysis of most of that dataset (1943–59) confirmed these results over six cycles of a 3-year rotation (fallow–wheat–oats) with superphosphate applied at 0, 3, 6, 9, and 12 kg P/ha. However, continuation of the experiment in the same plots with a 2-year rotation (fallow–wheat or pasture–wheat) found no further cumulative benefit of residual P on grain yields. Over four decades from 1962 to 2001, yields remained generally constant, after adjusting for growing-season rainfall, with the differences in yield between rates of applied superphosphate also remaining constant over the period. On average, adding 3 kg P/ha was estimated to increase yield by 0.45 t/ha (compared with 0 kg P/ha) and adding 6, 9, and 12 kg P/ha resulted in estimated step-wise yield increases of 0.10 t/ha, 0.10 t/ha, and 0.01 t/ha, respectively.

scholarly journals Response of wheat, pea, and canola to micronutrient fertilization on five contrasting prairie soils

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Noabur Rahman ◽  
Jeff Schoenau
Keyword(s):  
Foliar Application ◽  
Relative Effectiveness ◽  
Yield Response ◽  
Soil Extraction ◽  
Dominant Form ◽  
Prairie Soils ◽  
Biomass Yields ◽  
Mineral Soils ◽  
Yield Responses ◽  
Cu And Zn

Abstract A polyhouse study was conducted to evaluate the relative effectiveness of different micronutrient fertilizer formulation and application methods on wheat, pea and canola, as indicated by yield response and fate of micronutrients in contrasting mineral soils. The underlying factors controlling micronutrient bioavailability in a soil–plant system were examined using chemical and spectroscopic speciation techniques. Application of Cu significantly improved grain and straw biomass yields of wheat on two of the five soils (Ukalta and Sceptre), of which the Ukalta soil was critically Cu deficient according to soil extraction with DTPA. The deficiency problem was corrected by either soil or foliar application of Cu fertilizers. There were no significant yield responses of pea to Zn fertilization on any of the five soils. For canola, soil placement of boric acid was effective in correcting the deficiency problem in Whitefox soil, while foliar application was not. Soil extractable Cu, Zn, and B concentration in post-harvest soils were increased with soil placement of fertilizers, indicating that following crops in rotation could benefit from this application method. The chemical and XANES spectroscopic speciation indicates that carbonate associated is the dominant form of Cu and Zn in prairie soils, where chemisorption to carbonates is likely the major process that determines the fate of added Cu and Zn fertilizer.

scholarly journals Meta-Analysis of the Effects of Triazole-Based Fungicides on Wheat Yield and Test Weight as Influenced by Fusarium Head Blight Intensity

2010 ◽  
Vol 100 (2) ◽  
pp. 160-171 ◽  
Author(s):  
P. A. Paul ◽  
M. P. McMullen ◽  
D. E. Hershman ◽  
L. V. Madden
Keyword(s):  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Wheat Yield ◽  
Test Weight ◽  
Response To Treatment ◽  
Yield Response ◽  
Head Blight ◽  
Yield Increase ◽  
Soft Red Winter Wheat ◽  
Red Winter Wheat

Multivariate random-effects meta-analyses were conducted on 12 years of data from 14 U.S. states to determine the mean yield and test-weight responses of wheat to treatment with propiconazole, prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole. All fungicides led to a significant increase in mean yield and test weight relative to the check (D; P < 0.001). Metconazole resulted in the highest overall yield increase, with a D of 450 kg/ha, followed by prothioconazole+tebuconazole (444.5 kg/ha), prothioconazole (419.1 kg/ha), tebuconazole (272.6 kg/ha), and propiconazole (199.6 kg/ha). Metconazole, prothioconazole+tebuconazole, and prothioconazole also resulted in the highest increases in test weight, with D values of 17.4 to 19.4 kg/m3, respectively. On a relative scale, the best three fungicides resulted in an overall 13.8 to 15.0% increase in yield but only a 2.5 to 2.8% increase in test weight. Except for prothioconazole+tebuconazole, wheat type significantly affected the yield response to treatment; depending on the fungicide, D was 110.0 to 163.7 kg/ha higher in spring than in soft-red winter wheat. Fusarium head blight (FHB) disease index (field or plot-level severity) in the untreated check plots, a measure of the risk of disease development in a study, had a significant effect on the yield response to treatment, in that D increased with increasing FHB index. The probability was estimated that fungicide treatment in a randomly selected study will result in a positive yield increase (p+) and increases of at least 250 and 500 kg/ha (p250 and p500, respectively). For the three most effective fungicide treatments (metconazole, prothioconazole+tebuconazole, and prothioconazole) at the higher selected FHB index, p+ was very large (e.g., ≥0.99 for both wheat types) but p500 was considerably lower (e.g., 0.78 to 0.92 for spring and 0.54 to 0.68 for soft-red winter wheat); at the lower FHB index, p500 for the same three fungicides was 0.34 to 0.36 for spring and only 0.09 to 0.23 for soft-red winter wheat.

Effect of the number of parents and their combining ability on the performance of synthetic varieties in tall fescue

2007 ◽  
Vol 58 (11) ◽  
pp. 1100 ◽  
Author(s):  
E. Piano ◽  
P. Annicchiarico ◽  
M. Romani ◽  
L. Pecetti
Keyword(s):  
Inbreeding Depression ◽  
Tall Fescue ◽  
Combining Ability ◽  
Diallel Cross ◽  
Forage Yield ◽  
Yield Response ◽  
Temperature Pattern ◽  
Synthetic Varieties ◽  
Yield Values ◽  
Yield Responses

Finding the optimal parent number for synthetic varieties has a crucial importance in forage breeding. The objective of this work was exploring this number for Mediterranean tall fescue selected for forage yield. The general (GCA) and specific (SCA) combining ability of parents, and their effects on the performance and the inbreeding depression of synthetics, were also assessed. The full-sib families from the diallel cross of 20 genotypes chosen from well performing populations were evaluated for fresh biomass over 13 harvests in Sanluri (Sardinia, Italy). The Syn 1 and Syn 2 of 15 synthetics varying in parent number (4, 8, 12, 16 or 20) and, within same number, in mean GCA of parents were evaluated for dry matter yield over 11 harvests in Lodi (northern Italy) in a greenhouse simulating the temperature pattern of a Mediterranean environment. The yield responses of Syn 2 synthetics with 2 to 20 parents with highest mean GCA were predicted from yield values of S1 and F1 progenies, also evaluated in Lodi. The variance of GCA effects was almost 2-fold larger than that of SCA effects. The observed vigour loss from Syn 1 to Syn 2 of the 4-parent synthetics (−6%) tended to be greater than those of higher parent number groups. The 4-parent synthetics with larger SCA effects tended to greater inbreeding depression. The comparison among synthetics with different parent number and highest GCA of their parents indicated the superiority of the 4-parent synthetic over any other in both generations (P < 0.05). The predicted yield response was maximised by the 3-parent synthetic. The results and other considerations suggest adoption of 4- to 6-parent synthetics.

Applications of the herbicide sethoxydim increase wheat yield in the absence of weeds

1996 ◽  
Vol 36 (5) ◽  
pp. 555
Author(s):  
ID Black ◽  
CB Dyson ◽  
AR Fischle
Keyword(s):  
Leaf Growth ◽  
Wheat Yield ◽  
South Australia ◽  
Growing Season ◽  
Degree Days ◽  
Experimental Site ◽  
Yield Increase ◽  
Growing Seasons ◽  
Positive Linear Correlation ◽  
Area North

In 11 experiments over 6 seasons the herbicide sethoxydim was applied to Machete, Spear and Blade wheat cultivars in the absence or near absence of weeds (10 sites) or where the weeds were controlled by selective herbicides (1 site), in the cropping area north of Adelaide, South Australia. The rates applied included 9-47 g a.i./ha at the 2-3 leaf growth stage and 9-74 g a.i./ha at early tillering. Except for the very long growing season of 1992, there was a highly significant positive linear correlation between the number of degree days in the growing season at each experimental site and relative mean yield increase of these sethoxydim treatments. Yield increases ranged from nil in growing seasons of about 1000 degree days to 32% in a growing season of 1480 degree days, with a median of 8% over the experiments.

scholarly journals Wheat yield responses to stomatal uptake of ozone: Peak vs rising background ozone conditions

2018 ◽  
Vol 173 ◽  
pp. 1-5 ◽  
Author(s):  
Harry Harmens ◽  
Felicity Hayes ◽  
Gina Mills ◽  
Katrina Sharps ◽  
Stephanie Osborne ◽  
...  
Keyword(s):  
Wheat Yield ◽  
Background Ozone ◽  
Yield Responses

Post-anthesis sink size in a high-yielding dwarf wheat: yield response to grain number

1977 ◽  
Vol 28 (2) ◽  
pp. 165 ◽  
Author(s):  
RA Fischer ◽  
I Aguilar ◽  
DR Laing
Keyword(s):  
Grain Yield ◽  
Wheat Yield ◽  
Kernel Weight ◽  
Yield Response ◽  
High Fertility ◽  
Grain Number ◽  
Wide Range ◽  
Carbon Dioxide Fertilization ◽  
Sink Size ◽  
The One

Experiments to study the effect of grain number per sq metre on kernel weight and grain yield in a high-yielding dwarf spring wheat (Triticum aestivum cv. Yecora 70) were conducted in three seasons (1971–1973) under high-fertility irrigated conditions in north-western Mexico. Crop thinning, shading and carbon dioxide fertilization (reported elsewhere), and crowding treatments, all carried out at or before anthesis, led to a wide range in grain numbers (4000 to 34,000/m2). Results indicated the response of grain yield to changing sink size (grains per sq metre), with the post-anthesis environment identical for all crops each year, and with all but the thinner crops intercepting most of the post-anthesis solar radiation. Kernel weight fell linearly with increase in grain number over the whole range of grain numbers studied, but the rate of fall varied with the season. Grain yield, however, increased, reaching a maximum at grain numbers well above those of crops grown with optimal agronomic management but without manipulation. It was concluded that the grain yield in normal crops was limited by both sink and post-anthesis source. There was some doubt, however, as to the interpretation of results from crowded crops, because of likely artificial increases in crop respiration on the one hand, and on the other, in labile carbohydrate reserves in the crops at anthesis. Also deterioration in grain plumpness (hectolitre weight) complicates the simple inference that further gains in yield can come from increased grain numbers alone.

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