Correlation of soil phosphorus tests with the response of irrigated perennial pasture to phosphorus fertilizer

1978 ◽  
Vol 18 (91) ◽  
pp. 243 ◽  
Author(s):  
AJ Montgomery ◽  
G Rubenis
Keyword(s):  
Soil Phosphorus ◽  
Maximum Yield ◽  
Correlation Coefficients ◽  
Response Functions ◽  
Phosphorus Fertilizer ◽  
Soil Tests ◽  
Yield Data ◽  
P Values ◽  
Olsen P ◽  
Pasture Yield

The level of soil phosphorus and the response of irrigated perennial pasture to phosphorus fertilizer were measured on 33 sites in the Goulburn Valley of northern Victoria. Eleven of the 33 sites were found to have Olsen P values above 10 p.p.m. and Colwell P values above 30 p.p.m. Of these 11, 9 did not give a pasture response to superphosphate and 2 gave a relatively small response. Functions of the form Y = a - be-CX (where Y = total pasture yield over 12 months (t ha-1), X = rate of superphosphate application (t ha-1), and a, b and c are constants respectively denoting maximum yield, maximum response, and the rate at which maximum yield is approached) were fitted to the yield data from those sites at which a response did occur. b was found to be correlated with a number of soil tests, the highest correlation coefficient being -0.74 for Colwell P. a was significantly correlated with some tests (P < 0.01) but was generally less predictable, and c gave very low correlation coefficients with all soil tests.

Response by sugar beet to superphosphate, particularly in relation to soils containing little available phosphorus

1976 ◽  
Vol 86 (1) ◽  
pp. 181-187 ◽  
Author(s):  
A. P. Draycott ◽  
M. J. Durrant
Keyword(s):  
Sugar Beet ◽  
Soil Phosphorus ◽  
Maximum Yield ◽  
P Uptake ◽  
Available Phosphorus ◽  
Triple Superphosphate ◽  
Phosphorus Fertilizer ◽  
Average Yield ◽  
Soil P ◽  
The Cost

SUMMARYTwenty experiments between 1970 and 1974 tested the effect of five amounts of triple superphosphate (0–110 kg P/ha) on sugar-beet yield in fields where soil contained little sodium bicarbonate-soluble phosphorus. The average yield without phosphorus fertilizer was 6·69 t/ha sugar and the increase from the optimum dressing 0·46 t/ha; the average soil concentration was 12 mg P/l. The fertilizer increased yield by 0·77 t/ha sugar on fields with 0–9 mg/l soil phosphorus, by 0·31 t/ha when soil phosphorus was 10–15 mg/l and had little effect on soils containing larger amounts.The concentration of phosphorus in plants harvested in mid-summer contained on average 0·29% P in dried tops and 0·13% in roots when given no phosphorus fertilizer, representing a total of 19·3 kg/ha P uptake. Giving superphosphate increased the phosphorus in both dried tops and roots by up to 0·03% and there was 3·7 and 1·7 kg/ha more phosphorus in tops and roots respectively. On the most responsive fields (0–9 mg/l soil P), the fertilizer increased the phosphorus in tops and roots by 0·05% and total uptake by 7 kg P/ha. The increase in uptake (or recovery) of fertilizer varied from 15% when 14 kg P/ha was given to less than 5% when 110 kg P/ha was used.A dressing of 27 kg P/ha was adequate for maximum yield on 19 of the 20 fields. When fields were grouped, 0–9, 10–15, 16–25 and > 26 mg/l NaHCO3-soluble soil phosphorus, and taking into account the value of the increased sugar yield, the cost of the fertilizer and its residual value, 60, 30, 20 and 10 kg P/ha respectively were the most profitable dressings. These experiments provide evidence, however, that the fertilizer would be used more efficiently if fields containing 0–9 mg soil phosphorus were subdivided into those with 0–4·5 and those with 4·6–9·0 mg/l and the groups given 80 and 40 kg P/ha respectively. These recommendations are substantially less than those used at present; they are adequate for sugar beet but other crops in the rotation would need similar close examination to ensure maximum yield and maintain adequate soil reserves of phosphorus.

Soil phosphorus tests II: A comparison of soil test–crop response relationships for different soil tests and wheat

2013 ◽  
Vol 64 (5) ◽  
pp. 469 ◽  
Author(s):  
Simon D. Speirs ◽  
Brendan J. Scott ◽  
Philip W. Moody ◽  
Sean D. Mason
Keyword(s):  
Grain Yield ◽  
Confidence Intervals ◽  
Buffer Capacity ◽  
Soil Phosphorus ◽  
Soil Test ◽  
Soil Tests ◽  
P Values ◽  
Soil P ◽  
Soil P Test ◽  
R Value

The performance of a wide range of soil phosphorus (P) testing methods that included established (Colwell-P, Olsen-P, BSES-P, and CaCl2-P) and more recently introduced methods (DGT-P and Mehlich 3-P) was evaluated on 164 archived soil samples corresponding to P fertiliser response experiments with wheat (Triticum aestivum) conducted in south-eastern Australia between 1968 and 2008. Soil test calibration relationships were developed for relative grain yield v. soil test using (i) all soils, (ii) Calcarosols, and (iii) all ‘soils other than Calcarosols’. Colwell-P and DGT-P calibration relationships were also derived for Calcarosols and Vertosols containing measureable CaCO3. The effect of soil P buffer capacity (measured as the single-point P buffer index corrected for Colwell-P, PBICol) on critical Colwell-P values was assessed by segregating field sites based on their PBICol class: very very low (15–35), very low (36–70), low (71–140), and moderate (141–280). All soil P tests, except Mehlich 3-P, showed moderate correlations with relative grain yield (R-value ≥0.43, P < 0.001) and DGT-P exhibited the largest R-value (0.55). Where soil test calibrations were derived for Calcarosols, Colwell-P had the smallest R-value (0.36), whereas DGT-P had an R-value of 0.66. For ‘soils other than Calcarosols’, R-values >0.45 decreased in the order: DGT-P (r = 0.55), Colwell-P (r = 0.49), CaCl2-P (r = 0.48), and BSES-P (r = 0.46). These results support the potential of DGT-P as a predictive soil P test, but indicate that Mehlich 3-P has little predictive use in these soils. Colwell-P had tighter critical confidence intervals than any other soil test for all calibrations except for soils classified as Calcarosols. Critical Colwell-P values, and confidence intervals, for the very very low, very low, and low P buffer capacity categories were within the range of other published data that indicate critical Colwell-P value increases as PBICol increases. Colwell-P is the current benchmark soil P test used in Australia and for the field trials in this study. With the exception of Calcarosols, no alternative soil P testing method was shown to provide a statistically superior prediction of response by wheat. Although having slightly lower R-values (i.e. <0.1 difference) for some calibration relationships, Colwell-P yielded tighter confidence intervals than did any of the other soil tests. The apparent advantage of DGT-P over Colwell-P on soils classified as Calcarosols was not due to the effects of calcium carbonate content of the analysed surface soils.

scholarly journals Sward structure and herbage yield of rotationally stocked pastures of 'Marandu' palisadegrass [Brachiaria brizantha (A.Rich.) Stapf] as affected by herbage allowance

2006 ◽  
Vol 63 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Gustavo José Braga ◽  
Carlos Guilherme Silveira Pedreira ◽  
Valdo Rodrigues Herling ◽  
Pedro Henrique de Cerqueira Luz ◽  
César Gonçalves de Lima
Keyword(s):  
Accumulation Rate ◽  
Live Weight ◽  
Grazing Intensity ◽  
Linear Increase ◽  
The Other ◽  
Brachiaria Brizantha ◽  
Yield Data ◽  
Sward Height ◽  
Pasture Yield ◽  
Sward Structure

In ruminant-forage systems herbage allowance (HAL) has a major impact on grazing intensity and sward structure, affecting animals, plants, and ultimately, pasture yield. Data on HAL responses of tropical cultivated pastures are scarce and this information may be useful in optimizing pasture utilization. The objective of this study was to describe and contrast sward structure and herbage accumulation responses of 'Marandu' palisadegrass [Brachiaria brizantha (A.Rich.) Stapf] pastures to HAL during two grazing seasons (warm-rainy season of 2003 and 2004). Treatments were four daily HAL levels, 5, 10, 15 and 20 kg herbage mass per 100 kg live weight (%) in a rotational stocking system with 35 days of grazing cycle (28-day rest; 7-d grazing). Post-graze swards were shorter (~17 cm) under 5% HAL. For the other HAL levels, postgraze sward height increased throughout the experiment (21 to 50 cm). Changes in sward light interception (LI) were highly associated with height, but differed across HALs in 2004. Early in the 2003 season, HAL increases resulted in linear increase of the daily herbage accumulation rate (HAR; 47, 66, 78, and 98 kg DM ha-1 d-1 for 5, 10, 15 and 20%-HAL, respectively). For the subsequent grazing cycles of 2003 and all through 2004, HAR decreased with increasing HAL. This was associated with the excessive increase in sward height and mean forage mass, caused by lower grazing intensity. The use of lax (high) HAL to maximize animal performance, especially 10, 15 and 20%-HAL, resulted in decreased pasture performance (lower herbage accumulation, HAC) in palisadegrass pastures.

scholarly journals Changes in availability and uptake of soil phosphorus influenced by management practices and crop growth stages under peanut cultivation in medium black clay soil of Saurashtra region, Gujarat

2020 ◽  
Vol 41 (6) ◽  
pp. 1781-1787
Author(s):  
R.S. Yadav ◽  
◽  
H.N. Meena ◽  
N.K. Jain ◽  
D. Bhaduri ◽  
...  
Keyword(s):  
Plant Growth ◽  
Management Practices ◽  
Nutrient Management ◽  
Soil Phosphorus ◽  
Phosphorus Uptake ◽  
Clay Soils ◽  
Growth Stages ◽  
Olsen P ◽  
Black Clay ◽  
Raised Bed

Aim: To investigate efficient utilization of soil phosphorus for peanut nutrition through integration of management practices in medium black clay soils of Saurashtra region in Gujarat. Methodology: Soil phosphorus availability and uptake by peanut plants were assessed at five plant growth stages under six different management practices in Kharif season. The availability of soil P was estimated by Olsen P and Resin P extraction methods. The biomass production and phosphorus uptake at each growth stages were observed in order to draw the relationship between these parameters.? Results: The management practices like raised bed with polythene mulch, integrated and organic nutrient management was consistently found promising for enhanced availability and uptake of soil phosphorus under peanut cultivation. The Olsen P decreased with plant growth under all the management options, except organic and integrated nutrient management practices.? In contrary, the resin P generally increased with plant growth, especially under inorganic and organic nutrient management and raised bed with polythene mulch practices. Irrespective of growth stages, the phosphorus uptake by peanut plants was significantly and strongly correlated with biomass production (r=0.85, p<0.01) and Olsen P (r=0.41, P<0.05).? Interpretation: The results indicate that phosphorus requirement of peanut plants can be efficiently met by integrating land and nutrient management practices in these medium black clay soils.

scholarly journals Effect of Cow Dung, Biogas Slurry and Vermicompost on Phosphorus Adsorption Behavior of Soil

2015 ◽  
Vol 7 (3) ◽  
pp. 167-175 ◽  
Author(s):  
M. Seafatullah ◽  
M. A Hoque ◽  
M. S. Islam ◽  
M. M. Islam ◽  
M. N. Islam
Keyword(s):  
Adsorption Capacity ◽  
Soil Phosphorus ◽  
Phosphate Fertilizer ◽  
Phosphorus Release ◽  
Adsorption Behavior ◽  
Cow Dung ◽  
Biogas Slurry ◽  
Fertilizer Management ◽  
Phosphorus Fertilizer ◽  
Phosphorus Adsorption

One of the approaches for phosphorus fertilizer management is controlling the soil phosphorus adsorption behavior. To examine the effect on phosphorus adsorption behavior, three amended soil samples were prepared by mixing 10% (w/w in dry basis) cow dung, biogas slurry and vermicompost with soil. Phosphorus adsorption behavior was examined by using Langmuir, and Temkin adsorption isotherms. Initially, biogas slurry and vermicompost increased the maximum phosphorus adsorption capacity (MPAC) of soil from 461 µg g-1 (control) to 558.0357 and 586.17 µg g-1 respectively, and then decreased steadily and reached 429.92 and 398.41 µg g-1 respectively in five weeks.  Whereas in case of cow dung, MPAC was initially decreased, then reached maximum in 17 days and ultimately decreased. Thus application of cow dung along with phosphate fertilizer seems to increase the loss of the fertilizer through runoff and leaching. Conversely, biogas slurry and vermicompost prevent phosphorus loss by regulating phosphorus release through initial enhancement followed by gradual decrease in phosphorus adsorption capacity of soil. Both biogas slurry and vermicompost can be considered as good soil amendments as they have the ability to control the release of phosphorus fertilizer as per the need of the plants.

scholarly journals Increased Foot and Tibial Angles at Footstrike Decrease Vertical Loadrate in Runners

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0048
Author(s):  
Adam Tenforde ◽  
Haylee Donaghe Borgstrom ◽  
Steve Jamison ◽  
Irene Davis
Keyword(s):  
Injury Risk ◽  
Loading Rate ◽  
Sagittal Plane ◽  
Video Recording ◽  
Correlation Coefficients ◽  
Group Differences ◽  
P Values ◽  
Source Program ◽  
Running Injuries ◽  
The Relationship

Category: Sports Introduction/Purpose: It is well established that elevated vertical loadrates on footstrike are a risk factor for developing running injuries. Overstriding, or increased foot and tibial angles at footstrike, has been theorized to increase loading rate. Thus, it is often suggested that runners shorten their stride to reduce their injury risk. However, the relationship between landing alignment and loadrates has not been well established in current literature. Thus, we aimed to investigate the relationship between sagittal plane foot angle (FA) and tibial angle (TA) with vertical loadrates in both healthy and injured forefoot (FFS) and rearfoot strike (RFS) runners. It was hypothesized that as FA and TA increased, loadrate would increase for all runners. Methods: This is an ongoing study with 52 healthy runners (35 RFS, 17 FFS) and 24 injured runners (14 RFS, 10 FFS) for a total of 76 runners (51 M, 25 F; age34.3±11.4 yrs). Vertical average loadrate (VALR) and vertical instantaneous loadrate (VILR) were obtained while running at 2.68 m/s on an instrumented treadmill. All runners reported 0/10 pain during the assessment. Sagittal plane FA and TA at footstrike were measured from video recording using an open-source program. Positive FA designated RFS. Positive TA was defined as ankle anterior to the knee. Between-group differences were evaluated using paired two-tailed t-tests. Correlation coefficients (r) were computed for FA and TA with VALR and VILR (p=0.05; trend: p =0.10). Results: Healthy RFS - FA and TA were negatively correlated with VALR and VILR. Injured RFS – There was a trend toward negative correlation between TA and both VALR and VILR. Healthy FFS – TA was negatively correlated with both loadrates. Injured FFS – There were no significant correlations. Correlation coefficients, slopes, and p values are presented in Table 1. VALR and VILR were higher in RFS vs FFS runners (56±20 vs 40±10, 69±25 vs 54±12 BW/s, p<0.01), but were not significantly different for healthy vs injured runners (52±19 vs 56±26, 63±21 vs 67±27 BW/s, p=0.4). Conclusion: In contrast to current thought, preliminary results suggest that increasing FA and TA at footstrike are associated with decreasing vertical loadrates. This relationship was strongest for FA in the healthy RFS runners and weakest for FA in both the healthy and injured FFS runners. With increased FA, load attenuation may be due to increased eccentric activity of the tibialis anterior as well as increased knee flexion excursion and eccentric quadriceps activity with increased TA.

EFFECT OF SOLUBLE SALTS ON PLANT RESPONSE TO AND ABSORPTION OF PHOSPHORUS

1963 ◽  
Vol 43 (2) ◽  
pp. 210-218 ◽  
Author(s):  
W. S. Ferguson ◽  
R. A. Hedlin
Keyword(s):  
Salt Concentration ◽  
Saline Soil ◽  
Soil Phosphorus ◽  
Soil Extract ◽  
Plant Response ◽  
Phosphorus Fertilizer ◽  
Soluble Salts ◽  
Higher Plant ◽  
Phosphorus Absorption ◽  
Nacl Concentration

Fertilizer experiments indicated that much higher plant response to phosphorus occurred on moderately saline than on non-saline soil. Soil analyses showed that this difference could not be explained by the amount of sodium bicarbonate extractable phosphorus contained in these two soils.Greenhouse experiments with artificially salinized soil indicated that the uptake of phosphorus by barley plants was related to the salt concentration in the soil. Phosphorus absorption increased with increasing salt concentration, reached a maximum when the saturation soil extract measured approximately 6 millimhos, and then declined with further increases in salt concentration. This relationship was similar for fertilized and unfertilized plants. However, the increase in phosphorus absorption was much greater when phosphorus fertilizer was applied.The same relationship between salt concentration and phosphorus absorption was obtained with increasing NaCl concentration in liquid cultures. Maximum phosphorus absorption by barley occurred when the solution contained between 0.05 and 0.10 molar NaCl This relationship is attributed to the effect of salts on the physiology of the plant rather than the effect of salts on phosphorus solubility.

Reliability of Shear Wave Ultrasound Elastography for Neck Lesions Identified in Routine Clinical Practice

2012 ◽  
Vol 33 (05) ◽  
pp. 463-468 ◽  
Author(s):  
K. Bhatia ◽  
C. S. L. Tong ◽  
C. C. M. Cho ◽  
E. H. Y. Yuen ◽  
J. Lee ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Shear Wave ◽  
Correlation Coefficients ◽  
Routine Clinical Practice ◽  
Ultrasound Elastography ◽  
Concordance Correlation ◽  
Substantial Agreement ◽  
P Values ◽  
Static Image ◽  
Acquisition Technique

Abstract Purpose: To evaluate the reliability of shear wave ultrasound elastography (SWE) in the neck. Materials and Methods: 176 neck lesions (40 thy roid, 56 lymph nodes, 46 salivary, 34 miscella neous) identified in a routine US clinic underwent SWE by one or two blinded radiologists. For this study, SWE required the operator to acquire three 10 second dynamic colour-coded SWE cineloops per lesion, select one static image per cineloop, and place circular regions-of-interest within the entire lesion and stiffest part to generate 3 SWE measurements per static image. For logistical rea sons, one radiologist evaluated all 176 lesions and the other evaluated 58 lesions. Both radiologists also reviewed 27 archived cineloops independ ently to assess SWE excluding practical technique. Reliability was assessed using intraclass correla tion coefficients (ICCs) concordance correlation coefficients (CCCs) and coefficients of repeatabil ity (CORs). Results: Test-retest ICCs for the radiologist evalu ating 176 lesions were 0.78–0.85 (fair-excellent agreement), CCCs were 0.85–0.88 (substantial agreement), and CORs were 14.9–36.1 kPa. For both radiologists evaluating 58 lesions, intra-rater and inter-rater ICCs were 0.65–0.78 and 0.72–0.77 respectively. For SWE excluding practical technique, inter-rater ICCs were 0.97–0.98 (ex cellent agreement). ICCs differed according to tis sue, being higher in thyroid lesions than lymph nodes (p < 0.001), and higher in benign than ma lignant lesions (p values < 0.001). Conclusion: Intra- and inter-rater reliability of SWE is fair to excellent according to ICCs. SWE re liability is influenced appreciably by acquisition technique. Nevertheless, CORs for SWE are not negligible. To determine whether these results are acceptable clinically, further research is re quired to establish SWE stiffness values of normal and pathological tissues in the neck.

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.

A comparison of some surface soil phosphorus tests that could be used to assess P export potential

Soil Research ◽  
2007 ◽  
Vol 45 (5) ◽  
pp. 397 ◽  
Author(s):  
David Nash ◽  
Murray Hannah ◽  
Kirsten Barlow ◽  
Fiona Robertson ◽  
Nicole Mathers ◽  
...  
Keyword(s):  
Organic P ◽  
Soil Tests ◽  
Soil P ◽  
Olsen P ◽  
P Sorption ◽  
P Loss ◽  
Extractable P ◽  
Soil P Tests ◽  
Total P ◽  
Water Extractable

Phosphorus (P) exports from agricultural land are a problem world-wide and soil tests are often used to identify high risk areas. A recent study investigated changes in soil (0–20 mm), soil water and overland flow in 4 recently laser-graded (<1 year) and 4 established (laser-graded >10 years) irrigated pastures in south-eastern Australia before and after 3 years of irrigated dairy production. We use the results from that study to briefly examine the relationships between a series of ‘agronomic’ (Olsen P, Colwell P), environmental (water-extractable P, calcium chloride extractable P, P sorption saturation, and P sorption), and other (total P, organic P) soil P tests. Of the 2 ‘agronomic’ soil P tests, Colwell P explained 91% of the variation in Olsen P, and Colwell P was better correlated with the other soil tests. With the exception of P sorption, all soil P tests explained 57% or more of the total variation in Colwell P, while they explained 61% or less of Olsen P possibly due to the importance of organic P in this soil. Variations in total P were best explained by the organic P (85%), Calcium chloride extractable P (83%), water-extractable P (78%), and P sorption saturation (76%). None of the tests adequately predicted the variation in P sorption at 5 mg P/L equilibrating solution concentration. The results of this limited study highlight the variability between soil P tests that may be used to estimate P loss potential. Moreover, these results suggest that empirical relationships between specific soil P tests and P export potential will have limited resolution where different soil tests are used, as the errors in the relationship between soil test P and P loss potential are compounded by between test variation. We conclude that broader study is needed to determine the relationships between soil P tests for Australian soils, and based on that study a standard protocol for assessing the potential for P loss should be developed.

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