Methodology for online biometric analysis of soil test–crop response datasets

2013 ◽  
Vol 64 (5) ◽  
pp. 435 ◽  
Author(s):  
C. B. Dyson ◽  
M. K. Conyers

Comprehensive data on grain yield responsiveness to applications of the major nutrients nitrogen, phosphorus, potassium, sulfur in Australian cropping experiments have been assembled in the Better Fertiliser Decisions for Cropping (BFDC) National Database for scrutiny by the BFDC Interrogator. The database contains the results of individual field experiments on nutrient response that need to be collectively integrated into a model that predicts probable grain yield response from soil tests. The potential degree of grain yield responsiveness (relative yield, RY%) is related to nutrient concentration in the soil (soil test value, STV) across a range of experimental sites and conditions for each nutrient. The RY% is defined as RY = Y0/Ymax *100, where Y0 is the yield without applied nutrient, and Ymax is the yield which could be attained through adequate application of the nutrient, given sufficiency of all other nutrients. The raw data for RY and STV are transformed so that a linear regression model can be applied. The BFDC Interrogator uses the arcsine-log calibration curve (ALCC) algorithm to estimate a critical soil test value (CSTV) for a given nutrient. The CSTV is defined as the value that would, on average for the broad agronomic circumstances of the incoming crop, lead to a specified percentage of Ymax (e.g. RY = 90%) without any application of that nutrient. This paper describes the ALCC algorithm, which has been developed to ensure that such estimated CSTVs, with safeguards, are reliable and to as high a precision as is realistic.

2002 ◽  
Vol 42 (2) ◽  
pp. 149 ◽  
Author(s):  
M. D. A. Bolland ◽  
W. J. Cox ◽  
B. J. Codling

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kelly A. Nelson ◽  
Peter P. Motavalli ◽  
William E. Stevens ◽  
John A. Kendig ◽  
David Dunn ◽  
...  

Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S), 0-0-25-17, 3-18-18-0, and 5-0-20-13) and additive rates (2.2, 8.8, and 17.6 kg K ha−1) on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1in a low-yield year (2005) depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K(P=0.03), S(P=0.03), B(P=0.0001), and Cu(P=0.008)concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.


2019 ◽  
Vol 70 (4) ◽  
pp. 295 ◽  
Author(s):  
Geoffrey Anderson ◽  
Richard Bell

Soil acidity, or more specifically aluminium (Al) toxicity, is a major soil limitation to growing wheat (Triticum aestivum L.) in the south of Western Australia (SWA). Application of calcium carbonate (lime) is used to correct Al toxicity by increasing soil pH and decreasing soluble soil Al3+. Soil testing using a 0.01 m calcium chloride (CaCl2) solution can measure both soil pH (pHCaCl2) and soil Al (AlCaCl2) for recommending rates of lime application. This study aimed to determine which combination of soil pHCaCl2 or soil AlCaCl2 and sampling depth best explains the wheat grain-yield increase (response) when lime is applied. A database of 31 historical lime experiments was compiled with wheat as the indicator crop. Wheat response to lime application was presented as relative yield percentage (grain yield for the no-lime treatment divided by the highest grain yield achieved for lime treatments × 100). Soil sampling depths were 0–10, 10–20 and 20–30 cm and various combinations of these depths. For evidence that lime application had altered soil pHCaCl2, we selected the change in the lowest pHCaCl2 value of the three soil layers to a depth of 30 cm as a result of the highest lime application (ΔpHmin). When ΔpHmin &lt;0.3, the lack of grain-yield response to lime suggested that insufficient lime had leached into the 10–30 cm soil layer to remove the soil Al limitation for these observations. Also, under high fallow-season rainfall (228 and 320 mm) and low growing-season rainfall (GSR) (&lt;140 mm), relative yield was lower for the measured level of soil AlCaCl2 than in the other observations. Hence, after excluding observations with ΔpHmin &lt;0.3 or GSR &lt;140 mm (n = 19), soil AlCaCl2 provided a better definition of the relationship between soil test and wheat response (r2 range 0.48–0.74) than did soil pHCaCl2 (highest r2 0.38). The critical value (defined at relative yield = 90%) ranged from 2.5 mg Al kg–1 (for soil Al calculated according to root distribution by depth within the 0–30 cm layer) to 4.5 mg Al kg–1 (calculated from the highest AlCaCl2 value from the three soil layers to 30 cm depth). We conclude that 0.01 m CaCl2 extractable Al in the 0–30 cm layer will give the more accurate definition of the relationship between soil test and wheat response in SWA.


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.


2013 ◽  
Vol 64 (5) ◽  
pp. 424 ◽  
Author(s):  
G. Watmuff ◽  
D. J. Reuter ◽  
S. D. Speirs

During the past 50 years, 3800 field experiments yielding over 5200 treatment series were conducted in Australia examining yield responses to applied N, P, K, or S fertiliser applications to cereal, oilseed and pulse crops. The experiments all had accompanying soil test data. These data were entered into multiple Microsoft Access® database templates and then consolidated into a single national online MYSQL® database. A web application (named the BFDC Interrogator) was also developed to rapidly access the national database (BFDC National Database) and construct soil test calibrations between percentage of the maximum grain yield achieved (hereafter called percentage relative yield) and soil test values recorded for specified ranges of regional or national experiments. Search parameters were applied to define soil test calibrations. These included farming system (dryland or irrigated), year of experiment, soil type, crop type, soil test, depth of soil sampling and soil test units. Other data filters based on site metadata, such as method of nutrient placement, can be applied to enable more definitive calibrations. The calibrations are used to derive critical soil test values at 80, 90 and 95% relative crop yield with 95% confidence limits. However, the soil test criteria at 90% relative crop yield with 70% confidence limits have been chosen as the single calibration and reliability standard for all crops and soil tests. Corresponding yield increase (t/ha)–soil test relationships for an applied nutrient can also be accessed. The BFDC National Database and BFDC Interrogator can now be accessed online by trained, registered users. This paper describes the methodologies that underpinned the progressive development of this tool. Through the commitment of the grains and fertiliser industries, it is anticipated that the calibrations will be used to improve decision support systems used to generate fertiliser recommendations for Australian cropping industries.


Soil Research ◽  
2017 ◽  
Vol 55 (4) ◽  
pp. 341 ◽  
Author(s):  
Craig A. Scanlan ◽  
Ross F. Brennan ◽  
Mario F. D'Antuono ◽  
Gavin A. Sarre

Interactions between soil pH and phosphorus (P) for plant growth have been widely reported; however, most studies have been based on pasture species, and the agronomic importance of this interaction for acid-tolerant wheat in soils with near-sufficient levels of fertility is unclear. We conducted field experiments with wheat at two sites with acid soils where lime treatments that had been applied in the 6 years preceding the experiments caused significant changes to soil pH, extractable aluminium (Al), soil nutrients and exchangeable cations. Soil pH(CaCl2) at 0–10cm was 4.7 without lime and 6.2 with lime at Merredin, and 4.7 without lime and 6.5 with lime at Wongan Hills. A significant lime×P interaction (P<0.05) for grain yield was observed at both sites. At Merredin, this interaction was negative, i.e. the combined effect of soil pH and P was less than their additive effect; the difference between the dose–response curves without lime and with lime was greatest at 0kgPha–1 and the curves converged at 32kgPha–1. At Wongan Hills, the interaction was positive (combined effect greater than the additive effect), and lime application reduced grain yield. The lime×P interactions observed are agronomically important because different fertiliser P levels were required to maximise grain yield. A lime-induced reduction in Al phytotoxicity was the dominant mechanism for this interaction at Merredin. The negative grain yield response to lime at Wongan Hills was attributed to a combination of marginal soil potassium (K) supply and lime-induced reduction in soil K availability.


Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 167 ◽  
Author(s):  
ICR Holford ◽  
JM Morgan ◽  
J Bradley ◽  
BR Cullis

In a study using data from 57 wheat field experiments on the central-western slopes of New South Wales, eight soil phosphate tests (Bray,, Bray,, alkaline fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. The results showed that, regardless of how well correlated a soil test is with yield responsiveness, it cannot give a satisfactory estimate of fertilizer requirement unless yield response curvature is also taken into account. The tendency of soil test values, especially of the Colwell test, to be negatively related to response curvature, and hence inversely related to fertilizer effectiveness, compounded the problem of directly relating soil test values to fertilizer requirement. The best test (lactate) accounted for only 28% of the variance in fertilizer requirement, compared with 50% of the variance in responsiveness, and the worst test (Colwell) was completely unrelated to fertilizer requirements. When fertilizer requirement was estimated from the lactate test value and the actual response curvature for each experiment, 68% of the variance (from the actual fertilizer requirement) was accounted for. Thirteen experiments were subject to drier conditions than the others, and these were less responsive and had lower fertilizer requirements relative to soil test values. In relation to yield responsiveness, the Colwell test was most sensitive (P < 0.001) to dry conditions, while the two best tests (lactate and Bray,) were the least sensitive (P > 0.05). The results demonstrated the superiority of acidic anionic extractants over alkaline bicarbonate extractants on moderately acid to alkaline wheat-growing soils.


Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 195 ◽  
Author(s):  
Timothy Boring ◽  
Kurt Thelen ◽  
James Board ◽  
Jason De Bruin ◽  
Chad Lee ◽  
...  

To determine if current university fertilizer rate and timing recommendations pose a limitation to high-yield corn (Zea mays subsp. mays) and soybean (Glycine max) production, this study compared annual Phosphorous (P) and Potassium (K) fertilizer applications to biennial fertilizer applications, applied at 1× and 2× recommended rates in corn–soybean rotations located in Minnesota (MN), Iowa (IA), Michigan (MI), Arkansas (AR), and Louisiana (LA). At locations with either soil test P or K in the sub-optimal range, corn grain yield was significantly increased with fertilizer application at five of sixteen site years, while soybean seed yield was significantly increased with fertilizer application at one of sixteen site years. At locations with both soil test P and K at optimal or greater levels, corn grain yield was significantly increased at three of thirteen site years and soybean seed yield significantly increased at one of fourteen site years when fertilizer was applied. Site soil test values were generally inversely related to the likelihood of a yield response from fertilizer application, which is consistent with yield response frequencies outlined in state fertilizer recommendations. Soybean yields were similar regardless if fertilizer was applied in the year of crop production or before the preceding corn crop. Based on the results of this work across the US and various yield potentials, it was confirmed that the practice of applying P and K fertilizers at recommended rates biennially prior to first year corn production in a corn–soybean rotation does not appear to be a yield limiting factor in modern, high management production systems.


2020 ◽  
Vol 71 (9) ◽  
pp. 795 ◽  
Author(s):  
Therese M. McBeath ◽  
Evelina Facelli ◽  
Courtney A. E. Peirce ◽  
Viran Kathri Arachchige ◽  
Michael J. McLaughlin

The ability to utilise foliar-applied phosphorus (P) as a strategy to increase the P status and yield of grain crops grown in dryland regions with variable climates is attractive. Several P formulations with varying pH, accompanying cations and adjuvants were tested for their effectiveness as foliar fertilisers for wheat (Triticum aestivum L.) plants, first under controlled and then under field conditions. Experiments under controlled conditions suggested that several formulations with specific chemistries offered promise with respect to wheat fertiliser-P recovery and biomass responses. These formulations were then evaluated in two field experiments, and although wheat grown at the sites showed substantive responses to soil-applied P, there was no significant grain-yield response to foliar-applied P. Following the limited responses to foliar-applied fertiliser in the field, we used an isotopic dilution technique to test the hypothesis that the variation in responses of wheat to foliar addition of P could be explained by a mechanism of substitution, whereby root P uptake is downregulated when P is taken up through the leaves, but this was proven not to be the case. We conclude that foliar P application cannot be used as a tactical fertiliser application to boost grain yield of wheat in dryland regions.


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.


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