Sodium bicarbonate soil test values and the phosphate buffering capacity of soils

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 263 ◽  
Author(s):  
KR Helyar ◽  
K Spencer
Keyword(s):  
Sodium Bicarbonate ◽  
Field Experiments ◽  
Critical Level ◽  
Soil Phosphorus ◽  
Buffering Capacity ◽  
Soil Test ◽  
Preliminary Estimate ◽  
Test Functions ◽  
Soil Phosphate ◽  
Phosphorus Levels

Fifty-one field experiments dealing with responses of subterranean and white clover pastures to applied phosphate at a range of soil phosphorus levels, were carried out. The level of sodium bicarbonate extractable phosphorus above which little or no response to applied phosphate occurs (critical level), increased from 22 to 48 pg phosphorus/g soil with increases in soil phosphate buffering capacity (at solution [P] of 0.3 pg phosphorus/ml) from 1 to 20 ml/g x 10-1. On the few highly buffered soils occurring outside this range critical levels up to 60 �g phosphorus/g soil were indicated. A preliminary estimate is made of the way yield/soil test functions vary with changes in soil phosphate buffering capacity.

Yield responsiveness and response curvature as essential criteria for the evaluation and calibration of soil phosphate tests for wheat

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 167 ◽  
Author(s):  
ICR Holford ◽  
JM Morgan ◽  
J Bradley ◽  
BR Cullis
Keyword(s):  
Field Experiments ◽  
Yield Response ◽  
Soil Test ◽  
Wheat Field ◽  
Fertilizer Effectiveness ◽  
Soil Phosphate ◽  
Fertilizer Requirement ◽  
Dry Conditions ◽  
Using Data ◽  
Actual Response

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.

Phosphate and potash requirements of sugar cane in relation to soil chemical analysis and soil type

1966 ◽  
Vol 6 (23) ◽  
pp. 409
Author(s):  
ICR Holford
Keyword(s):  
Sugar Cane ◽  
Soil Type ◽  
Field Experiments ◽  
Soil Phosphorus ◽  
Soil Test ◽  
Mitscherlich Equation ◽  
Percentage Yield ◽  
Significant Yield ◽  
Highly Correlated ◽  
Yield Responses

The superphosphate and potassium chloride requirements of sugar cane were studied in relation to soil test levels on 25 different soil types in Fiji. Soil phosphorus was determined by a modified Truog method and soil potassium by extraction with 0.5N acetic acid. Percentage yields of sugar cane in fertilizer field experiments harvested over a five-year period were highly correlated with soil test levels in the control plots. The regressions of percentage yield on soil test level were curvilinear, and a modified Mitscherlich equation gave an excellent fit to the points. Critical soil test levels were found to exist, below which soils gave significant yield responses to applied nutrients. Critical soil test levels ranged over 5 to 20 p.p.m, for phosphorus and 51 to 150 p.p.m. for potassium. Within the deficient range of each nutrient there were only weak relationships between optimum fertilizer requirements and soil test levels. There was some evidence to suggest that soil type may be a useful complementary criterion for predicting fertilizer requirements.

scholarly journals Glyphosate sorption and desorption in soils with distinct phosphorus levels

2003 ◽  
Vol 60 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Fábio Prata ◽  
Vanessa Camponez do Brasil Cardinali ◽  
Arquimedes Lavorenti ◽  
Valdemar Luiz Tornisielo ◽  
Jussara Borges Regitano
Keyword(s):  
Experimental Design ◽  
Complex Formation ◽  
Adsorption Capacity ◽  
Phosphorus Content ◽  
Soil Phosphorus ◽  
Soil Samples ◽  
Point Of View ◽  
Phosphate Adsorption ◽  
Soil Phosphate ◽  
Phosphorus Levels

The sorption of glyphosate by soils occurs due to the inner sphere complex formation with metals of soil oxides, which are related to the soil phosphate adsorption capacity. The aim of this study was to evaluate the effects of increasing rates of phosphorus on sorption and desorption of glyphosate in three soils with different mineralogical attributes. Soils were a Rhodic Kandiudalf, an Anionic Acrudox and a Typic Humaquept. Soil samples were amended with KH2PO4 at equivalent rates of 0; 1,000; 5,000; 20,000 and 50,000 kg ha-1 of P2O5, which are high from the agricultural point of view, but necessary in order to perform sorption and desorption studies. The experimental design consisted of a completely randomized factorial: 2 soils x 5 phosphorus rates and 3 replicates. For the sorption experiments, five glyphosate solutions were employed (0.42; 0.84; 1.68; 3.36 and 6.72 mg L-1), with a 14C radioactivity of 0.233 kBq mL-1. Four steps of the desorption procedure with CaCl2 0.01 mol L-1 and one extraction with Mehlich 3 were performed only at one concentration (0.84 mol L-1). Soil samples were afterwards biologically oxidized to establish the radioactive balance. Glyphosate competes with phosphorus for specific sorption sites, but this competition becomes important when phosphorus is present at rates higher than 1,000 mg dm-3. Moreover, a small amount of applied glyphosate was extracted (<10%), and the extraction increased with increasing soil phosphorus content.

Available phosphorus in alkaline soils in relation to the growth of tick bean (Vicia faba L.Var. Minor Beck)

1958 ◽  
Vol 9 (5) ◽  
pp. 633
Author(s):  
D McEAlexander ◽  
RC Woodham
Keyword(s):  
Sodium Bicarbonate ◽  
Carbonic Acid ◽  
Soil Phosphorus ◽  
Extraction Methods ◽  
Available Phosphorus ◽  
Alkaline Soils ◽  
Fresh Weight ◽  
Weight Yield ◽  
Soluble Phosphorus ◽  
Phosphorus Levels

Responses in the growth of tick bean in the field to applications of superphosphate have been related to "available" phosphorus in irrigated alkaline soils. Tick bean is grou7n as a winter corer crop between vine rows in irrigation areas of the Murray Valley. Availability of soil phosphorus was assessed by its solubility either in carbonic acid or in a solution of sodium bicarbonate. The first reagent extracted phosphorus ranging from 0.7 to 24 p.p.m. of the surface 6 in. of soil sampled from the various test areas prior to the sowing of tick bean, while the second extracted 5-91 p.p.m. Both extraction methods gave similar relations between soluble phosphorus in the soil and the response in growth of tick bean to 2 cwt superphosphate per acre applied at sowing. Thus, considering the carbonic acid extract, the increase in fresh weight yield of green herbage of bean plant ranged from about 30 per cent. for soil initially at a level of 3 p.p.m. of soluble phosphorus to about 10 per cent. for soil initially at 10 p.p.m. These phosphorus levels correspond to about 20 and 46 p.p.m. as determined by the sodium bicarbonate extraction method.

Effect of topdressed phosphorus fertilizer on established white clover based pastures in south-east Queensland. 1. Prediction of yield responses using soil tests

1979 ◽  
Vol 19 (99) ◽  
pp. 454 ◽  
Author(s):  
GE Rayment ◽  
RC Bruce
Keyword(s):  
White Clover ◽  
Field Experiments ◽  
Soil Phosphorus ◽  
Relative Yield ◽  
Pasture Production ◽  
Phosphorus Status ◽  
Empirical Tests ◽  
Yield Responses ◽  
Phosphorus Levels ◽  
Term Field

Seventeen short-term field experiments were conducted over a five year period in south-east Queensland in which rates of up to 60 kg P ha-1 as monocalcium phosphate were topdressed onto established, previously grazed, grass-white clover (Trifolium repens) pastures, Increases (P < 0.05) in yields of white clover were obtained at seven sites, but concurrent increases in grass production occurred at only four sites. Higher total pasture production resulted at six of these sites. One quantitative (total) and two empirical (0.005 M H2SO4 and 0.5 M Na HCO3) estimates of phosphorus status in 0-10 cm soil samples, collected prior to topdressing treatments, were separately correlated with relative yield responses of white clover, grass and total pasture components. Although soil phosphorus levels by all methods were statistically intercorrelated (P < 0.01), acid-extractable and total phosphorus tests were generally unsuitable for predictive purposes, having low coefficients of determination for regressions and Cate-Nelson separations of responsive from non-responsive sites. Bicarbonate-extractable phosphorus proved the most suitable soil test. It accounted for 60 and 44% of the variance in relative yields of white clover and total pasture, respectively, but was poorly correlated with relative yields of grass. The suggested critical level of soil phosphorus (bicarbonate extraction) for white clover is 28 ppm P. For total pasture, responses are likely below 22, unlikely above 28 and uncertain between 22 and 28 ppm P, respectively. Percentage variance in relative yields already explained by both empirical tests was not significantly increased by inclusion of terms for pH and exchangeable calcium into the X variable.

Estimation of Soil Phosphorus Levels in Shrimp Ponds

2000 ◽  
Vol 5 (1) ◽  
pp. 115
Author(s):  
G. Ritvo ◽  
M. Sherman ◽  
A. L. Lawrence ◽  
T. M. Samocha
Keyword(s):  
Soil Phosphorus ◽  
Shrimp Ponds ◽  
Phosphorus Levels

The critical concentration of manganese in field-grown wheat

1985 ◽  
Vol 36 (2) ◽  
pp. 145 ◽  
Author(s):  
RD Graham ◽  
WJ Davies ◽  
JS Ascher
Keyword(s):  
Field Experiments ◽  
Critical Level ◽  
Critical Concentration ◽  
Optimal Growth ◽  
Mn Deficiency ◽  
Unreliable Method ◽  
Chlorophyll A Fluorescence Transients ◽  
Yield Responses ◽  
Fluorescence Transients ◽  
Wheat Tissues

The critical concentration of manganese (Mn) in wheat tissues for optimal growth was determined from field experiments. In the youngest emerged blade showing a ligule (YEB), the critical concentration was 11 � 1 8g g-1 (DW). The critical concentrations for older blades and whole tops were: next leaf below YEB, 13 � 1 8g g-1 DW; older leaves, 16 � 1 8g g-1 DW; whole tops, 12 � 1 8g g-1 DW. The older blades were less sensitive determinants of the growth response and are not recommended tissues for analysis. Diagnosis using whole tops was less sensitive than with YEB, but analysis of whole tops may give an integrated picture of Mn deficiency where availability varies rapidly with time. The critical concentration of 11 � 1 8g g-1 in the YEB for growth is also the critical level for the appearance in that leaf of normal chlorophyll a fluorescence transients. The Fo/Fv ratio, a parameter of the leaf fluorescence transients, correlated well with the Mn concentration in the leaf and may prove suitable for the diagnosis of Mn deficiency in field-grown wheat. The critical level of Mn was the same for two genotypes differing in their ability to tolerate Mn deficiency in the soil. Grain yield responses and other relevant data collected over three years are presented. Analysis of grain was shown to be an unreliable method of diagnosing an earlier Mn deficiency in the crop.

Soil test phosphorus as affected by phosphorus budgets in two long-term field experiments in Germany

2018 ◽  
Vol 218 ◽  
pp. 158-170 ◽  
Author(s):  
Theresa Zicker ◽  
Sabine von Tucher ◽  
Mareike Kavka ◽  
Bettina Eichler-Löbermann
Keyword(s):  
Field Experiments ◽  
Soil Test ◽  
Phosphorus Budgets ◽  
Soil Test Phosphorus ◽  
Term Field
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