Boundary-line analysis of field-scale yield response to soil properties

2004 ◽  
Vol 142 (5) ◽  
pp. 553-560 ◽  
Author(s):  
T. M. SHATAR ◽  
A. B. MCBRATNEY
Keyword(s):  
Soil Properties ◽  
Maximum Yield ◽  
Smoothing Splines ◽  
Yield Potential ◽  
Yield Response ◽  
Boundary Line ◽  
Property Value ◽  
Data Scatter ◽  
Yield Responses ◽  
Changes In Soil Properties

An algorithm to fit boundary lines, using cubic smoothing splines, was written and used to identify yield responses to changes in soil properties. This method involves fitting a curve that represents the maximum yield response to each predictor value, which represents the yield potential at each soil property value. Boundary-line yield responses to individual soil properties were found to differ from responses found by fitting curves through the data scatter. The effects of correlated variables appeared to be lessened using the boundary line approach. Multivariate boundary-line models, based on the Law of the Minimum, were found to be useful for the identification of site-specific causes of yield variation and yield potentials. The boundary line was found to be a useful complement to more traditional data analysis techniques.

Response of six-row barley to N and P2O5 fertilizer application in high fertility sites in Central Alberta

1991 ◽  
Vol 71 (2) ◽  
pp. 317-326 ◽  
Author(s):  
K. G. Briggs
Keyword(s):  
Agronomic Traits ◽  
Maximum Yield ◽  
Fertilizer Application ◽  
Yield Potential ◽  
Yield Response ◽  
High Fertility ◽  
Fertility Level ◽  
Fertilizer Response ◽  
Fertilizer Recommendations ◽  
Yield Responses

Two series of N and P2O5 fertilizer response trials were conducted at a total of five sites in Central Alberta in 1985 and 1986 to determine whether a range of barley (Hordeum vulgare) cultivars differed in their response to high levels of fertility application under high-yielding conditions. The cultivars included were two semidwarf (Samson, Duke) and three of conventional height (Leduc, Klondike and Johnston). No cultivar × fertility level interaction was obtained for grain yield in any of the trials, although significant interactions of minor magnitude were found for other agronomic traits in some trials. The most important of these traits was extent of lodging which was at a low level (less than 3 on the 0.2–9 Belgian Scale) in all trials, despite average grain yields ranging from 4000 to 6289 kg ha−1. Lodging was more severe in Johnston than in the other cultivars. Yields of the semidwarf s were no higher than those of Leduc in any trial, although minor lodging occurred for Leduc in some cases. Lack of significant cultivar × fertility interaction may be partially explained by the general lack of response to the higher fertility levels that were used, although good yield response was found to addition of 45 kg ha−1 of P2O5 in four of six trials, and to addition of up to 90 kg ha−1 of N in three of the six trials. No significant correlation was found between initial soil test N and P2O5 versus the mean year-site yield for different locations, suggesting that factors other than base soil fertility were more important in determining site-year yield potential. These results suggest that use of individualized fertilizer recommendations for targeting maximum yield for any of the cultivars studied is not warranted, since the cultivars demonstrated similar yield responses. The excellent straw strength advantage of the semidwarf cultivars was reconfirmed under these high yielding conditions, but yields over 6000 kg ha−1 with several taller cultivars were also recorded without lodging (e.g. Leduc). Key words: Target yields, lodging, Intensive Crop Management®, cultivar specific fertilizer recommendations

Soil properties as predictors of yield response of clover (Trifolium subterraneum L.) to added P in soils of varying P sorption capacity

Soil Research ◽  
2003 ◽  
Vol 41 (4) ◽  
pp. 653 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland
Keyword(s):  
Soil Properties ◽  
Response Curve ◽  
Maximum Yield ◽  
Trifolium Subterraneum ◽  
Stepwise Multiple Regression ◽  
Yield Response ◽  
Soil Test ◽  
Organic Carbon Content ◽  
Soil Test P ◽  
Yield Responses

Thirty-five unfertilised soils collected in south-western Australia were used to measure the effect of soil properties on (i) shoot yield responses of 50-day-old clover (Trifolium subterraneum L. cv. Nungarin) plants to applied phosphorus (P), and (ii) extractability of bicarbonate soil test P (slope of the linear relationship between Colwell P and the amount of P applied). Data for the relationship between shoot yield and the amount of P applied were fitted to a rescaled Mitscherlich equation to calculate the amount of P required to produce 50% and 90% of the maximum yield (P50% and P90%) and determine the curvature (c) and n coefficients of the equation. When the value of n is 1.00, the response curve is exponential, and as the value of n increases above 1.00 the response curve becomes more sigmoidal. The c, n, P50%, P90%, and extractability values were related to properties of the 35 soils.There was a significant (P < 0.05) trend for the values of c and extractability to decrease as the capacity of the soil to sorb P increased. Consequently, as the soil sorbed more P, the trend was that (1) more P needed to be applied to produce the same yield, so both P50% and P90% tended to significantly (P < 0.05) increase; (2) shoot yield responses to applied P became more sigmoidal so the value of the n coefficient tended to significantly (P < 0.05) increase; (3) more P needed to be applied to a soil to produce the same soil test P value; and (4) larger soil test P values were needed to produce the same yield. No single soil property adequately predicted P50%, P90%, extractability, c, or n. Stepwise multiple regression indicated that (1) clay content and P buffer capacity (PBC) of soil together accounted for 48% of the variation in P50%, 56% of the variation in P90%, and 52% of the variation in c; (2) PBC and soil pH together accounted for 17% of the variation in n; and (3) PBC, percentage clay and percentage organic carbon content of soil together accounted for 68% of the variation in extractability.

Effects of Application Method and Rate on Control of Sclerotinia Blight of Peanut with Iprodione and Fluazinam1

2001 ◽  
Vol 28 (1) ◽  
pp. 28-33 ◽  
Author(s):  
J. P. Damicone ◽  
K. E. Jackson
Keyword(s):  
Disease Control ◽  
Disease Incidence ◽  
Maximum Yield ◽  
Wide Band ◽  
Yield Response ◽  
Application Method ◽  
Sclerotinia Blight ◽  
Progress Curve ◽  
Application Methods ◽  
Yield Responses

Abstract Two trials with iprodione and three trials with fluazinam were conducted to assess the effects of application method and rate on the control of Sclerotinia blight of peanut with fungicide. In order to concentrate the fungicides near the crown area where the disease causes the most damage, applications were made through a canopy opener with a single nozzle centered over the row to achieve a 30.5-cm-wide band (canopy opener), and through a single nozzle centered over the row to achieve a 46-cm-wide band (band). Broadcast applications were compared to these methods at rates of 0, 0.28, 0.56, and 1.12 kg/ha on the susceptible cultivar Okrun. Sclerotinia blight was severe, with &gt; 70% disease incidence and &lt; 2000 kg/ha yield for the untreated controls in each trial. Linear reductions in area under the disease progress curve (AUDPC), but not final disease incidence, with iprodione rate were significant (P &lt; 0.05) for all methods of application. However, the rate of decrease did not differ among application methods. Linear increases in yield with rate of iprodione were greater for canopy opener compared to the band or broadcast applications. Only a 50% reduction in AUDPC and a maximum yield of &lt; 2700 kg/ha was achieved with iprodione using the best method. At the maximum rate of 1.12 kg/ha, fluazinam provided &gt; 75% disease control and &gt; 4000 kg/ha yield for all application methods. Differences in disease control and yield among application methods only occurred at the 0.28 and 0.56 kg/ha rates of fluazinam. Reductions in AUDPC with fluazinam rate were quadratic for all application methods, but AUDPC values were less for the canopy opener and band methods at 0.28 and 0.56 kg/ha compared to the broadcast methods. The yield response to rate for broadcast applications of fluazinam was linear. However, predicted yield responses to fluazinam rate were quadratic for the band and canopy opener methods and approached the maximum response at 0.84 kg/ha. Targeting fungicide applications using the band and/or canopy opener methods was beneficial for fluazinam at reduced rates. Disease control with iprodione was not adequate regardless of application method.

Plant density response and optimum crop densities for canola (Brassica napus L.) in Western Australia

2016 ◽  
Vol 67 (4) ◽  
pp. 397 ◽  
Author(s):  
R. J. French ◽  
M. Seymour ◽  
R. S. Malik
Keyword(s):  
Brassica Napus ◽  
Western Australia ◽  
Maximum Yield ◽  
Yield Potential ◽  
High Yield ◽  
Yield Response ◽  
Asymptotic Model ◽  
Brassica Napus L ◽  
Optimum Density ◽  
Crop Density

In 24 experiments conducted across a range of agricultural environments in Western Australia between 2010 and 2014 canola (Brassica napus L.) grain yield response to crop density was adequately described by an asymptotic model (where yield approaches but never quite reaches a ceiling at very high density) in 101 out of 112 individual responses; in the other 11 yield reached a maximum and declined slightly at higher densities. Seed oil was more likely to increase than decrease with increasing density but the effect was always small; less than 1% oil over the range of densities tested. Increasing density also suppressed annual ryegrass (Lolium rigidum (L.) Gaud.) head numbers in six experiments where it was measured, especially at densities below 20 plants/m². Economic optimum densities ranged from 7 to 180 plants/m², with a median of 32.2. Mean optima in low and medium rainfall zones (growing season rainfall <300 mm) were about 25, 30, and 75 plants/m² respectively for glyphosate-tolerant (Roundup Ready), hybrid triazine-tolerant (TT), and open-pollinated TT cultivars, assuming open-pollinated TT cultivars were grown from farm-saved seed. There was little difference between optimum densities for hybrid and open-pollinated glyphosate-tolerant cultivars, and optima in the high rainfall zone were about 10 plants/m² higher than in low and medium rainfall zones. Yield at optimum density was greater than 90% of maximum yield in 74% of cases. The economic penalty for not achieving the optimum density with hybrids was usually small if the deviation was less than 10 plants/m², and with open-pollinated TT cultivars was small even 50-60 plants/m² below the optimum. The penalty was usually greater for deviations below than above the optimum in medium and high yield potential environments (yield potential >1000 kg/ha). Predicted optima were more sensitive to seed cost and field establishment (the proportion of viable seeds that become established) than grain price or seed size over the range of values expected in Western Australian agriculture. Field establishment varied from 0.3 to 1 and was higher at low target densities and for hybrid compared with open-pollinated cultivars, with a median of 0.585 at a target density of 40 plants/m². We identified improving field establishment of canola as an important research priority.

Determining the fertiliser phosphorus requirements of intensively grazed dairy pastures in south-western Australia with or without adequate nitrogen fertiliser

2007 ◽  
Vol 47 (7) ◽  
pp. 801 ◽  
Author(s):  
M. D. A. Bolland ◽  
I. F. Guthridge
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Maximum Yield ◽  
Dairy Herd ◽  
Yield Response ◽  
Soil Test ◽  
Mineral N ◽  
P Leaching ◽  
The Many ◽  
Yield Responses

Fertiliser phosphorus (P) and, more recently, fertiliser nitrogen (N) are regularly applied to intensively grazed dairy pastures in south-western Australia. However, it is not known if applications of fertiliser N change pasture dry matter (DM) yield responses to applied fertiliser P. In three Western Australian field experiments (2000–04), six levels of P were applied to large plots with or without fertiliser N. The pastures were rotationally grazed. Grazing started when ryegrass plants had 2–3 leaves per tiller. Plots were grazed in common with the lactating dairy herd in the 6-h period between the morning and afternoon milking. A pasture DM yield response to applied N occurred for all harvests in all three experiments. For the two experiments on P deficient soil, pasture DM yield responses also occurred to applications of P. For some harvests when no fertiliser N was applied, probably because mineral N in soil was so small, there was a small, non-significant pasture DM response to applied P and the P × N interaction was highly significant (P < 0.001). However, for most harvests there was a significant pasture DM response to both applied N and P, and the P × N interaction was significant (P < 0.05–0.01), with the response to applied P, and maximum yield plateaus to applied P, being smaller when no N was applied. Despite this, for the significant pasture DM responses to applied P, the level of applied P required to produce 90% of the maximum pasture DM yield was mostly similar with or without applied N. Evidently for P deficient soils in the region, pasture DM responses to applied fertiliser P are smaller or may fail to occur unless fertiliser N is also applied. In a third experiment, where the soil had a high P status (i.e. more typical of most dairy farms in the region), there was only a pasture DM yield response to applied fertiliser N. We recommend that fertiliser P should not be applied to dairy pastures in the region until soil testing indicates likely deficiency, to avoid developing unproductive, unprofitable large surpluses of P in soil, and reduce the likelihood of P leaching and polluting water in the many drains and waterways in the region. For all three experiments, critical Colwell soil test P (a soil test value that was related to 90% of the maximum pasture DM yield), was similar for the two fertiliser N treatments.

PREDICTION DES BESOINS EN ENGRAIS N, P et K DES LEGUMES CULTIVES EN SOL MINERAL: LES CHOUX

1983 ◽  
Vol 63 (1) ◽  
pp. 113-123
Author(s):  
EMILE CHAMBERLAND
Keyword(s):  
Maximum Yield ◽  
Field Trials ◽  
N Fertilization ◽  
Yield Response ◽  
Brussels Sprouts ◽  
High K ◽  
Fertilizer Recommendations ◽  
Mineral Soils ◽  
Yield Responses ◽  
K Fertilization

The objective of this study was to verify and improve the accuracy of fertilizer recommendations for growing cole crops on mineral soils. To achieve this end, 21 field trials were conducted on 12 soils during 1978–1981; of these trials, 13 were performed with late cabbage and Brussels sprouts and eight early cabbage and brocoli. The test crops were fertilized at four rates of N, P and K, and yield responses were related to soil test values. The Cate-Nelson iteration method was used to partition soils into three different classes according to their yield response to fertilization. Furthermore, polynomial and Mitscherlich equations were fitted to yield versus soil K and P data. These procedures suggested that fertilizer recommendations would be more precise by classifying these crops into early- and late-maturing groups. Accordingly, the recommended fertilization rates for soils containing a deficient or medium P supply were 70 and 80 kg P/ha for early and late crops, respectively. A clear yield response by early cabbage to K fertilization was indicated for soils containing a medium K supply; on these soils maximum yields would be achieved with an application of about 180 kg K/ha. On the other hand late cabbage and Brussels sprouts apparently only needed about 120 kg K/ha to achieve maximum yields on the same class of soils. While an increase in yields attributable to K fertilization is unlikely on soils containing a low and high K supply, a rate of 120 kg K/ha is nonetheless recommended to ensure maximum yield and maintain soil fertility levels. As regards N-fertilization, maximum yields early and late crop were produced with 160 and 180 kg N/ha, respectively. Key words: Fertilizer, N, P, K, vegetables, cabbages

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.

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