Fertilizer response for hybrid and open-pollinated canola and economic optimal nutrient levels

2010 ◽  
Vol 90 (3) ◽  
pp. 305-310 ◽  
Author(s):  
E G Smith ◽  
B M Upadhyay ◽  
M L Favret ◽  
R E Karamanos

Hybrid (HY) canola (Brassica napus L.) produces a higher seed yield than open-pollinated (OP) canola. While it is expected higher-yielding HY canola may require higher total available nutrients, especially nitrogen (N), the evidence is not conclusive. This study used canola yield data from several site-years and fertility experiments to determine whether HY and OP canola types require different rates of total available N (TAN) and total available phosphorus (TAP). The yield response of the two canola genotypes to TAP was the same, but for TAN the yield response was greater for HY canola. The quadratic yield response results were confirmed using three plateau equations. Optimal TAN for HY canola was higher than for OP canola. Soil test laboratories and producers growing HY canola need to modify N fertility for HY canola, compared with OP canola for which most of the current N fertilizer recommendations were developed. Key words: Economics, fertilizer, yield response, canola, hybrid, open-pollinated


1967 ◽  
Vol 47 (3) ◽  
pp. 175-185 ◽  
Author(s):  
R. F. Bishop ◽  
C. R. MacEachern ◽  
D. C. MacKay

In field experiments, conducted at 18 locations during a 3-year period, tuber yields on zero-P plots ranged from 49.7–95.5% of those obtained with optimum P fertilization. Each of three chemical methods used to estimate available soil P showed a wide range of values for the different locations.When Bray's modification of the Mitscherlich equation was used to express the relationship between soil test values and yield response to applied P, there were appreciable differences in c1 values which varied with soil series and soil test methods.Polynomial response curves showed that, irrespective of the chemical method used, if soils were grouped on the basis of available P into "high", "medium" and "low" classes, response to applied P was much less in the high than in the medium and low classes. Response curves also showed that both P requirements and maximum yields varied with different soil series.



1975 ◽  
Vol 15 (72) ◽  
pp. 93
Author(s):  
B Palmer ◽  
VF McClelland ◽  
R Jardine

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.



2003 ◽  
Vol 83 (4) ◽  
pp. 431-441 ◽  
Author(s):  
R. H. McKenzie ◽  
E. Bremer ◽  
L. Kryzanowski ◽  
A. B. Middleton ◽  
E. D. Solberg ◽  
...  

Crop responsiveness to P fertilizers on the Canadian Prairies has likely declined during the past three to four decades due to regular application of P fertilizer and reduced tillage. Its relationship to extractable soil P as determined by various soil tests may also have changed. The objective of this study was to evaluate five soil test P methods for three major crops across a wide range of soil types and environmental conditions. Small-plot P fertilizer trials were conducted at 154 locations across Alberta from 1991 through 1993. At each location, fertilizer responses were determined for one, two, or three crops: barley (Hordeum vulgare L.), spring wheat (Triticum aestivum L.) or canola (Brassica napus L.). Fertilizer treatments consisted of seed-placed monoammonium phosphate at rates of 0, 6.5, 13.1 and 19.6 kg P ha-1. The average increase in seed yield due to application of P fertilizer was 10%, with little difference among crop types. Relative yield increases were significantly greater in Gray soils (Dark Gray Chernozemics, Dark Gray-Gray Luvisols) than in Black (Black Chernozemics) or Brown soi ls (Brown and Dark Brown Chernozemics). The maximum variation in P fertilizer response accounted for by any soil test P was 27% for barley, 15% for wheat and 7% for canola. The Kelowna method and its derivatives generally provided the best fit with P fertilizer response. Only a modest increase in the proportion of variation that could be accounted for by soil test was achieved by multiple regressions with soil pH, clay or organic matter or by separate analyses of different soil types or years. The probability of a profitable yield response due to P fertilizer application did decline with increasing soil test P. However, profitable yield responses were frequent at all levels of soil test P for the first increment of 6.5 kg P ha-1 and low at all levels of soil test P for the third increment of 6.5 kg P ha-1 (19.6 kg P ha-1). The poor relationship of soil test P to fertilizer response was attributed to frequent but variable starter effects of P fertilizer and the infrequent occurrence of highly responsive sites. Key words: Soil testing, Olsen, Bray, Kelowna, fertilizer response functions, Hordeum vulgare, Triticum aestivum, Brassica napus



1968 ◽  
Vol 8 (30) ◽  
pp. 52
Author(s):  
JV Mullaly ◽  
JKM Skene ◽  
R Jardine

The predictability of three different measures of wheat yield response to superphosphate from each of four soil test measures of available phosphorus (0-6 inches) was examined, using data from field experiments over the period 1951 to 1965. The associations were studied separately within the three great soil groups that are dominant over the wheatgrowing areas of Victoria. Whichever measure of yield response was considered, soil bicarbonate P test measurement gave the best basis for prediction. However, at most, only 26 per cent of the yield response variability was predictable, and the other three tests were substantially less successful. Under the general conditions considered, where yield response is subject to a variety of uncorrected environmental deficiencies, it is concluded that the soil tests for P investigated in this paper are of doubtful practical value.



1987 ◽  
Vol 67 (4) ◽  
pp. 1105-1109 ◽  
Author(s):  
S. S. MALHI ◽  
V. S. BARON ◽  
D. K. McBEATH

Yield data from N fertilizer response experiments involving bromegrass (Bromus inermis L.) at four locations in central Alberta were fitted to quadratic regression equations. The marginal yield response to fertilizer N and the economic optimum N rates varied with soil climatic zones, being lowest at Botha, an area of low rainfall. Intensive management of grass-type hays appears most economical in the moist compared to dry areas.Key words: Bromus inermis, economics, hay, nitrogen fertlizer



Soil Research ◽  
1980 ◽  
Vol 18 (3) ◽  
pp. 353 ◽  
Author(s):  
WM Strong ◽  
G Barry

The uptake of native phosphorus and band-applied fertilizer phosphorus was studied for wheat (Triticum vulgare L. Oxley) and rape (Brassica napus L. Dwarf Essex) at two water regimes in a pot experiment. Soils were cracking clays known to differ in phosphorus availability. Both crops responded to fertilizer on Cecilvale (low available phosphorus), but not on Waco soil (high available phosphorus), and wheat also responded on Mywybilla soil (intermediate phosphorus). Fertilizer uptake was in the order: Cecilvale > Mywybilla > Waco for wheat and Cecilvale > Waco for rape. Crops recovered generally twice as much native phosphorus from each soil with the wet than with the dry regime. There was no effect of water regime on uptake of fertilizer phosphorus by wheat on any soil. Water regime did not increase fertilizer uptake by rape from Waco soil, although it did increase uptake on Cecilvale soil. Favourable fertilizer response under arid conditions appears to be due to a reduction in accessibility of native soil phosphorus due to the stunted root system, but no reduction in the availability of fertilizer phosphorus.



Soil Research ◽  
1967 ◽  
Vol 5 (2) ◽  
pp. 275 ◽  
Author(s):  
JD Colwell

The calibration of soil tests requires a statistical model to describe the relationship between yield of crop, fertilizer application rate, and soil test. Yield response to fertilizers can be represented by polynomials both in the natural and square-root scales, and these polynomials can be generalized for a given crop and region, using soil test expressions. The generalization can be done using orthogonal polynomials and simultaneous regression equations that relate the coefficients of the polynomials to the soil test variables. This procedure is necessary because of heterogeneity in the residual sum of squares of regressions fitted to the yield data of several fertilizer field experiments within a region. The set of simultaneous regression equations constitutes a direct calibration of the soil test, since it can be used for the estimation of economic fertilizer requirement. Highly significant calibrations are demonstrated for a phosphorus soil test with wheat and a potassium test with potatoes. A nitrogen test gave only non-significant (P > 0.05) relationships.



2013 ◽  
Vol 64 (5) ◽  
pp. 523 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Ken I. Peverill ◽  
Ross F. Brennan

Accurate definition of the sulfur (S) soil test–crop grain yield increase (response) relationship is required before soil S test measurements can be used to if there are likely to be responses to S fertilisers. An analysis was done using the Better Fertiliser Decision for Crops (BFDC) National Database using a web application (BFDC Interrogator) to develop calibration relationships between soil S tests (KCl-40 and MCP) using a selection of sampling depths and grain relative yields (RY). Critical soil test values (CSTV) and critical soil test ranges (CSTR) were defined at RY 90%. The ability of the KCl-40 extractable S soil test to predict grain yield response to applied S fertiliser was examined for wheat (Triticum aestivum L.) grown in Western Australia (WA), New South Wales (NSW), and Victoria and canola (Brassica napus L.) grown in WA and NSW. A smaller dataset using MCPi-extractable S was also assessed. The WA-grown wheat KCl-40 S CSTV, using sampling depth to 30 cm for soil types Chromosols (Coloured), Chromosols (Sesqui-Nodular), Kandosols (Grey and Yellow), Tenosols (Brown and Yellow), and Tenosols (Grey, Sesqui-Nodular), was 2.8 mg kg–1 with an associated CSTR 2.4–3.2 mg kg–1 and a correlation coefficient (r) 0.87. Similarly, KCl-40 S CSTV was defined using sampling depth to 10 cm for these selected soil types and for wheat grown on Vertosols in NSW. The accuracy of the KCl-40 S CSTV for canola grown in WA was improved using a sampling to a depth of 30 cm instead of 10 cm for all soil types. The canola KCl-40 S CSTV using sampling depth to 30 cm for these soil types was 7.2 mg kg–1 with an associated CSTR 6.8–7.5 and an r value 0.70. A similar KCl-40 S CSTV of 7.0 mg kg–1 was defined using a sampling depth of 10 cm, but the CSTR was higher (6.4–7.7 mg kg–1) and the r value lower (0.43). A lower KCl-40 S CSTV of 3.9 mg kg–1 or 31.0 kg ha–1 using a sampling depth of 60 cm was defined for canola grown in NSW using a limited number of S-rate calibration treatment series. Both MCPi (r = 0.32) and KCl-40 (r <0.20) soil S test–NSW canola response relationships using a 0–10 cm sampling depth were weak. The wheat KCl-40 S CSTR of 2.4–3.2 mg kg–1 can be used widely on soil types where soil sulfate is not leached during the growing season. However, both the WA canola CSTR of 6.4–7.2 mg kg–1 using a sampling depth of 30 cm and NSW canola CSTR of 25–39 kg ha–1 or 3.1–4.9 mg kg–1 using a sampling depth of 60 cm can be considered in regions outside of WA and NSW.



1996 ◽  
Vol 76 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. G. Kachanoski ◽  
G. L. Fairchild

Soil fertility may vary considerably within a field. The effects of variable soil fertility on the relationships among average crop yield response, average soil test, and fertilizer applied evenly to a field have not been examined. This paper develops stochastic equations to describe the average yield gain on a field basis from the application of a single constant rate of fertilizer, in fields with variable soil fertility. The equations are solved numerically for the specific case of nitrogen fertilizer on corn (Zea mays L.) in Ontario, Canada. The results suggest that since the relationships among yield response, soil test, and applied fertilizer are non-linear, a single soil test calibration cannot exist for fields with different spatial variability. Soil test calibrations obtained from sites with low variability (for example small plots) will not hold for sites with higher variability (for example farm fields). Calibrations obtained from sites with low variability will under-predict the optimum economic fertilizer rate for sites with low variability will under-predict the optimum economic fertilizer rate for sites with high variability. The results do not invalidate soil test calibration relationships per se. The challenge is to combine these calibrations with additional knowledge about the spatial distribution and field-scale variability of soil test values in order to maximize economic benefit. Key words: Spatial variability, soil test, fertilizer recommendation, yield, corn, field scale



1973 ◽  
Vol 81 (2) ◽  
pp. 311-316
Author(s):  
E. W. Bolle-Jones ◽  
F. Sanei

SummaryField experiments were conducted in four provinces of Iran in which sugar-beet yield responses to added nitrogen and phosphorus fertilizers were correlated with soil test values and number of irrigations.Although significant yield responses to fertilizer application were obtained in all four provinces, extremely few significant relationships were established between soil test values and yield response.Average crop yield was favourably influenced by the number of irrigations applied in Fare and Khorasan, by organic carbon status in Esfahan and Khorasan and adversely affected by increased soil conductivity in Esfahan and Khorasan. These results were taken to imply an inadequate number of irrigations in Fars and Khorasan. The high calcium carbonate status found in Fars soil adversely affected the level of average yield.Response to nitrogen fertilizer declined in Fars and Khorasan as the leaf nitrogen exceeded 3·15 and 4·0% respectively. Response to phosphate fertilizer declined in West Azerbaijan and Khorasan when leaf phosphorus exceeded 0·4%.



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