COMPARISON OF PARAMETERS OF SOIL PHOSPHATE AVAILABILITY FOR THE NORTHWESTERN CANADIAN PRAIRIE

1990 ◽  
Vol 70 (2) ◽  
pp. 227-237 ◽  
Author(s):  
Y. K. SOON
Keyword(s):  
Phosphoric Acid ◽  
Phosphate Buffer ◽  
Buffer Capacity ◽  
Field Experiments ◽  
Single Point ◽  
Relative Yield ◽  
P Availability ◽  
P Sorption ◽  
River Region ◽  
Chemical Extractants

A greenhouse experiment was conducted to evaluate several P availability parameters using 17 soils from the Peace River region of northwestern Canada. Only one soil was calcareous; the rest were acidic. The extractants tested included alkaline bicarbonate, acidic fluoride and 0.01 M CaCl2 solutions, and an anion exchange resin. Other availability indices evaluated were phosphoric acid potentials, phosphate buffer capacity and single point P sorption indices. The phosphoric acid potentials gave the highest correlation with percent relative yield of barley dry matter obtained after about 7 wk of growth. P sorption indices were not correlated with any crop response index. The phosphate buffer capacity and resin-extractable P performed at least as well as three chemical extractants: Olsen, Kelowna and Miller-Axley (modified) extractants. These three extractions were further evaluated using yield data from 11 field experiments with barley and 10 with rapeseed. There was little to choose from between these three extractants; however, the Kelowna extractant is a multi-element extractant and more convenient to use than the Olsen method. The Kelowna extractant also has a better buffering capacity, thus giving it a slight advantage over the modified Miller-Axley method for calcareous soils. These soil tests are, however, not fully satisfactory. In the greenhouse study, the Kelowna and Olsen methods made two errors and the modified Miller-Axley method three errors in prediction of P fertilizer requirement or non-requirement for the experimental soils. Key words: Soil testing, phosphate potential, chemical extractants, P sorption index, critical level

Phosphorus sorption by sandy soils from Western Australia: effect of previously sorbed P on P buffer capacity and single-point P sorption indices

Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1369 ◽  
Author(s):  
M. D. A. Bolland ◽  
D. G. Allen
Keyword(s):  
Retention Index ◽  
Western Australia ◽  
Buffer Capacity ◽  
Field Experiments ◽  
Single Point ◽  
Soil Test ◽  
Phosphorus Sorption ◽  
P Sorption ◽  
Soil Test P ◽  
Sorption Index

Soil samples collected from 8 field experiments in Western Australia to which 5–8 amounts of superphosphate had been applied once only 13–23 years previously were used to measure the phosphorus (P) buffer capacity of soil (PBC) and P sorption by several single-point indices. PBC was estimated from well-defined P sorption curves when several levels of P were added to soil suspensions, and was the amount of P sorbed when the concentration of P in the final solution was raised from 0.25 to 0.35 mg P/L. The single-point P sorption indices were measured by adding one amount of P (10 mg P/L) to soil suspensions (1 : 20, soil : 0.02 M KCl or 0.01 M CaCl2). Three indices were calculated from the amount of P sorbed by soil (S, mg P/kg soil) and the amount of P in solution (c, mg P/L)—(1) the phosphorus retention index (PRI, S/c [L/kg]), (2) the Freundlich retention index (FRI, S/c0.35 [dimensionless]), and (3) the phosphorus sorption index (PSI, S/log10 [c × 1000] [dimensionless])—to provide PRI K & Ca, FRI K & Ca, and PSI K & Ca values. P sorption was also measured by the P buffer index (PBI), the new single-point P sorption index recommended for national use, to provide PBICa values. To estimate the previous P sorbed by soil (native soil P is negligible for these soils, so previously sorbed P originates from fertiliser P applied in a previous year), the amount of P extracted by 0.5 M sodium bicarbonate from soil (Colwell soil test P) was added to the amount of P sorbed by soil to calculate PRI*K & Ca, FRI*K & Ca, PSI*K & Ca, and PBI*Ca values. In addition, previously sorbed P was estimated using the q coefficient of the Freundlich equation; q was added to P sorption to calculate PSI**, FRI**, PSI** and PBI** values to take account of previously sorbed P.For the 8 experiments, PBC values significantly decreased where more fertiliser P had been applied to the soils 13–23 years previously. This indicated that the capacity of the 8 soils to sorb P decreased as more P was applied in a previous year, and a single-point P sorption index would need to reflect this decrease. As the amount of P applied to soil in the field plots increased, the following trends occurred : (1) Colwell soil test P always increased; (2) PRIK & Ca, FRIK & Ca, PSIK & Ca, and PBICa consistently decreased; (3) PRI*K & Ca, FRI*K & Ca, PSI*K & Ca, and PBI*Ca mostly increased, but with some values being unaffected or decreasing; (4) PRI**, FRI**, PSI**, and PBI** values were largely unaffected by the amount of P applied in a previous year. Evidently, either adding Colwell soil test P or q to P sorption to calculate the single-point P sorption indices mostly overestimated P sorption by the sandy, low P sorbing soils used, but the overestimate was larger for Colwell soil test P than for q.

Interpretation of a single-point P buffering index for adjusting critical levels of the Colwell soil P test

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 55 ◽  
Author(s):  
P. W. Moody
Keyword(s):  
Buffer Capacity ◽  
Soil Phosphorus ◽  
Single Point ◽  
Maximum Yield ◽  
P Value ◽  
P Availability ◽  
Soil P ◽  
P Concentration ◽  
Soil P Test ◽  
Rate Of Increase

Soil phosphorus (P) buffer capacity is the change in the quantity of sorbed P required per unit change in solution P concentration. Because P availability to crops is mainly determined by solution P concentration, as P buffer capacity increases, so does the quantity of P required to maintain a solution P concentration that is adequate for crop demand. Bicarbonate-extractable P using the Colwell method is the most common soil P test used in Australia, and Colwell-P can be considered to estimate P quantity. Therefore, as P buffer capacity increases, the Colwell-P concentration required for maximum yield also increases. Data from several published and unpublished studies are used to derive relationships between the ‘critical’ Colwell-P value (Colwell-P at 90% maximum yield) and the single-point P buffer index (PBI) for annual medics, soybean, potato, wheat, and temperate pasture. The rate of increase in critical Colwell-P with increasing PBI increases in the order: temperate pasture < medics < wheat < potato. Indicative critical Colwell-P values are given for the 5 crops at each of the PBI categories used to describe soil P buffer capacity as it increases from extremely low to very high.

Effects of phosphate buffer capacity on yield response curvature and fertilizer requirements of wheat in relation to soil phosphate tests

Soil Research ◽  
1985 ◽  
Vol 23 (3) ◽  
pp. 417 ◽  
Author(s):  
ICR Holford ◽  
BR Cullis
Keyword(s):  
Phosphate Buffer ◽  
Buffer Capacity ◽  
Field Experiments ◽  
Significant Negative Correlation ◽  
Yield Response ◽  
Alkaline Soils ◽  
Soil Tests ◽  
Soil Phosphate ◽  
Fertilizer Requirement ◽  
Actual Response

Data from 39 fertilizer field experiments in north-western New South Wales were used to examine the effects of phosphate buffer capacity on yield response curvature and fertilizer requirements of wheat in relation to six soil phosphate tests (Bray1, Bray2, BSES, Truog, lactate, and bicarbonate). The soil tests were also evaluated for their accuracy in predicting yield responsiveness in a total of 48 experiments. There was a highly significant negative correlation between buffer capacity and response curvature, accounting for nearly 50% of the variance in curvature. The accuracy of the relationship was highest for moderately and strongly buffered soils. When used to predict curvature and hence fertilizer requirements, buffer capacity increased the variance accounted for by the most effective soil test (lactate) from 32% to 75%, compared with 93% using actual response curvatures. Whether used to predict responsiveness or fertilizer requirement, the lactate test was superior and the bicarbonate test was inferior to other soil tests. The bicarbonate test accounted for only half as much variance in responsiveness as the lactate test, and it accounted for none of the variance in fertilizer requirement. The results confirmed earlier studies showing that the bicarbonate test has several intrinsic properties which make it inferior to other soil tests on moderately acid to alkaline soils.

Soil phosphorus parameters affecting phosphorus availability to, and fertilizer requirements of, maize (Zea mays)

Soil Research ◽  
1988 ◽  
Vol 26 (4) ◽  
pp. 611 ◽  
Author(s):  
PW Moody ◽  
RL Aitken ◽  
BL Compton ◽  
S Hunt
Keyword(s):  
Zea Mays ◽  
Buffer Capacity ◽  
Single Point ◽  
Maximum Yield ◽  
P Uptake ◽  
Phosphorus Concentration ◽  
P Availability ◽  
Phosphorus Sorption ◽  
Soil P ◽  
Curvature Coefficient

The phosphorus status of each of 26 surface soils from Queensland was characterized by laboratory measurements and a glasshouse experiment. The glasshouse trial investigated the response between applied P in each soil and maize (Zea mays) dry matter yield. In the laboratory, the quantity of soil P was estimated by extraction with 0.5 M NaHCO3 (PB), and the intensity was estimated by soil solution P, 0.005 M CaCl2 extraction and equilibrium phosphorus concentration (EPC). Phosphorus-sorption curves were established for each soil and the data were used to derive the buffering index (BI) and equilibrium buffer capacity (EBC). Four single-point sorption indices were also determined. The desorption buffer capacity (dBC) of each soil was obtained in the laboratory by equilibrating soil samples with anion exchange resin for periods ranging from 0.1 to 18 h. This paper reports the relationships between the various P parameters and (i) the P uptake by maize (Zea mays) grown in untreated soil, and (ii) the amount of added P required for 90% maximum yield. Intensity, as estimated by EPC, was significantly (P < 0.001) correlated with P uptake. Any of the BI, EBC or the single-point sorption indices significantly improved the variation in P uptake accounted for by PB alone, but not to the same level as that obtained with EPC alone. When PB was combined with dBC, more variance was accounted for in P uptake than by using any of the adsorption buffer capacity measurements. The effects of quantity, intensity and buffer capacity on P availability are discussed in terms of their effects on P diffusion. For the suite of soils studied, it is concluded that intensity is the prime factor governing availability, and that the usefulness of adsorption buffer capacity measurements depends on their correlation with desorption buffer capacity. Variation in P requirement was best described by a combination of EPC and the Mitscherlich curvature coefficient, or EPC and one of the single-point sorption indices. As the single-point sorption indices were highly correlated with desorption buffer capacity, adsorption buffer capacity, and the curvature coefficient, they offer a convenient measure of the sorption properties of a soil.

Soil and tissue tests to predict pasture yield responses to applications of potassium fertiliser in high-rainfall areas of south-western Australia

2002 ◽  
Vol 42 (2) ◽  
pp. 149 ◽  
Author(s):  
M. D. A. Bolland ◽  
W. J. Cox ◽  
B. J. Codling
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Relative Yield ◽  
Subterranean Clover ◽  
Test Method ◽  
Yield Response ◽  
Soil Test ◽  
Test Procedures ◽  
Pasture Production ◽  
Yield Responses

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.

Inoculant formulation and fertilizer nitrogen effects on field pea: Nodulation, N2 fixation and nitrogen partitioning

2004 ◽  
Vol 84 (1) ◽  
pp. 79-88 ◽  
Author(s):  
G. W. Clayton ◽  
W. A. Rice ◽  
N. Z. Lupwayi ◽  
A. M. Johnston ◽  
G. P. Lafond ◽  
...  
Keyword(s):  
Pisum Sativum ◽  
Field Experiments ◽  
Field Pea ◽  
Nitrogen Partitioning ◽  
Residual Soil ◽  
N Accumulation ◽  
N Nutrition ◽  
Application Rates ◽  
River Region ◽  
Inoculant Formulation

Field pea (Pisum sativum L.) acreage has expanded rapidly in the past 10 yr in the Peace River Region of Alberta as well as western Canada. Understanding nitrogen dynamics of Rhizobium inoculants and applied N will provide farmers opportunities to improve N nutrition of field pea. Field experiments were conducted (a) to compare the effects of soil inoculation using granular inoculant, and seed inoculation using peat powder and liquid inoculants with an uninoculated check, on field pea nodulation and N2 fixation, and (b) to determine whether starter N is required by field pea to enhance N2 fixation. The effects of inoculant formulation on nodule number, N accumulation and N2 fixation were in the order: granular > peat powder > liquid = uninoculated. Field pea, from soil-applied inoculant, accumulated more N prior to and during podfilling than field pea with seed-applied inoculant. Fertilizer N application rates < 40 kg N ha-1 had no significant effects on biomass N at flatpod, indicating that starter N was not necessary. Application rates greater than 40 kg N ha-1 reduced nodulation, but the total amounts of N accumulated by plants did not vary. The close proximity of a highly concentrated band of N fertilizer had a greater impact on nodulation and subsequent N2 fixation than the residual soil N level. Under field conditions, soil-applied inoculant improved N nutrition of field pea compared to seed-applied inoculation, with or without applied urea-N. Key words: Granular inoculant, Pisum sativum, Rhizobium, inoculation, field pea, nodulation, N2 fixation

scholarly journals Plant size, nutrient composition and biomass productivity of oats and faba bean in intercropping, and the effect of controlling Rhopalosiphum padi (Hom., Aphididae) on these properties

1990 ◽  
Vol 62 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Juha Helenius
Keyword(s):  
Faba Bean ◽  
Field Experiments ◽  
Rhopalosiphum Padi ◽  
Relative Yield ◽  
Biomass Productivity ◽  
Plant Size ◽  
Damage Function ◽  
Point Of View ◽  
Daily Maximum ◽  
Replacement Series

Effects of mixed intercropping on plant size, content of mineral nutrients and biomass yields were examined in three field experiments in Southern Finland in 1983—1985. The stand types were monocrops and replacement series of mixtures with 2/3 and 1/3 or 1/3 and 2/3 of oats (Avena sativa) and faba bean (Vicia faba), respectively. In one of the experiments control of R. padi, by means of deltamethrin sprayings, was an additional experimental factor having two levels. The height of stems or the above ground biomass of oats either were not affected or were increased by crop diversification. Bean plants remained smaller in the mixtures than in the monocrop. In plant size, there was a significant interaction between stand type and the effect of aphicide spraying: Oat benefitted most from being grown in the mixture containing most bean, and there was an indication (not statistically significant) that in these mixtures bean had proportionately higher weight loss. This result was interpreted as giving some support to the hypothesis of interspecific compensation between oats and bean against aphid damage to oats. In oats, the content of N, P, K, Ca, and Mg all decreased from the stage of inflorescence emergence to the stage of the onset of milk development. Mixed cropping increased the content in oats of all these nutrients except Ca. At the same time, contents of P and K in bean were decreased. The changes in growth form and composition in oats induced by intercropping are discussed from the point of view of host plant relationship and damage function of the aphid pest. In terms of relative yield total (RYT), there was no overyielding in the dry matter, and in one case only was there overyielding in the nitrogen. During the period of population growth of R. padi, the daily maximum temperatures within the canopy were higher in the mixtures than in the monocrop of oats.

scholarly journals The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

2015 ◽  
Vol 43 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Dogan ISIK ◽  
Adem AKCA ◽  
Emine KAYA ALTOP ◽  
Nihat TURSUN ◽  
Husrev MENNAN
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Critical Period ◽  
Field Experiments ◽  
Yield Loss ◽  
Cropping Systems ◽  
Control Period ◽  
Relative Yield ◽  
Yield Data ◽  
Weed Interference

Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days) which corresponded to 8 to 66 days after crop emergence (DAE) and between 135-958 GDD (10 to 63 DAE) in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

scholarly journals Response of Barley Genotypes to Weed Interference in Australia

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 99 ◽  
Author(s):  
Gulshan Mahajan ◽  
Lee Hickey ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Negative Correlation ◽  
Weed Management ◽  
Field Experiments ◽  
Yield Loss ◽  
Production Systems ◽  
Relative Yield ◽  
Organic Production ◽  
Integrated Weed Management ◽  
Weed Interference ◽  
Barley Genotypes

Weed-competitive genotypes could be an important tool in integrated weed management (IWM) practices. However, weed competitiveness is often not considered a priority for breeding high-yielding cultivars. Weed-competitive ability is often evaluated based on weed-suppressive ability (WSA) and weed-tolerance ability (WTA) parameters; however, there is little information on these aspects for barley genotypes in Australia. In this study, the effects of weed interference on eight barley genotypes were assessed. Two years of field experiments were performed in a split-plot design with three replications. Yield loss due to weed interference ranged from 43% to 78%. The weed yield amongst genotypes varied from 0.5 to 1.7 Mg ha−1. Relative yield loss due to weed interference was negatively correlated with WTA and WSA. A negative correlation was also found between WSA and weed seed production (r = −0.72). Similarly, a negative correlation was found between WTA and barley yield in the weedy environment (r = −0.91). The results suggest that a high tillering ability and plant height are desirable attributes for weed competitiveness in the barley genotypes. These results also demonstrated that among the eight barley genotypes, Commander exhibited superior WSA and WTA parameters and therefore, could be used in both low- and high-production systems for weed management. Westminster had a superior WSA parameter. Therefore, it could be used for weed management in organic production systems. These results also implied that genotypic ranking on the basis of WSA and WTA could be used as an important tool in strengthening IWM programs for barley.

scholarly journals The Analysis of the Soil by means of the Plant

1905 ◽  
Vol 1 (1) ◽  
pp. 65-88 ◽  
Author(s):  
A. D. Hall
Keyword(s):  
Phosphoric Acid ◽  
Field Experiments ◽  
Weak Acid ◽  
Point Of View ◽  
Barley Straw ◽  
Plant Food ◽  
Living Plant ◽  
Ash Composition ◽  
Modern Methods ◽  
Plant Grown

One of the main problems placed before the agricultural chemist is the estimation of the requirements of a given soil for specific manures, or the interpretation, by means of data obtained in the laboratory, of the behaviour of the soil towards these manures, as seen in properly arranged field experiments. For various reasons the obvious method of determining the proportions of Nitrogen, Phosphoric Acid, and Potash in the soil fails in many cases to give the required information; even the more modern methods of measuring only the quantities of these materials which are attacked by weak acid solvents, and in consequence regarded as available to the plant, by no means always accord with the results of experience. Hence from time to time attempts have been made to attack the problem from another side and to use the living plant as an analytical agent. The scheme is to take a particular plant grown upon the soil in question, and determine in its ash the proportions of constituents like phosphoric acid and potash. Any deviations from the normal in these proportions may then be taken as indicating deficiency or excess of the same constituent in the soil and therefore the need or otherwise of specific manuring in that direction. The theory rests on two assumptions, first that each plant has a typical ash composition, constant when the plant is grown under similar conditions; secondly that the variations in the proportion of such a constituent as phosphoric acid will reflect the amount of that plant food available in the soil, as measured by the response of the crop to phosphatic manuring. From this point of view a number of investigations have already been made: Hellriegel discussed the relative variations of the proportion of potash in the ash of barley straw and of the soil in which it was grown; Heinrich analysed the roots of oats and fixed certain minima, below which the need for specific manuring was indicated.

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