scholarly journals Comparison of Soil Phosphorus Tests for Assessing Plant Availability of Phosphorus in an Ultisol Amended with Water-Soluble and Phosphate Rock Sources

2010 ◽  
Vol 10 ◽  
pp. 1679-1693
Author(s):  
E. W. Gikonyo ◽  
A. R. Zaharah ◽  
M. M. Hanafi ◽  
A. R. Anuar

The effectiveness of different soil tests in assessing soil phosphorus (P) in soils amended with phosphate rocks (PRs) is uncertain. We evaluated the effects of triple superphosphate (TSP) and PRs on extractable P by conventional soil tests (Mehlich 3 [Meh3] and Bray-1 [B1]) and a nonconventional test (iron oxide–impregnated paper, strip). Extracted amounts of P were in the order: Meh3 >B1 > strip. All the tests were significantly correlated (p= 0.001). Acidic reagents extracted more P from TSP than PRs, while the strip removed equal amounts from the two sources. The P removed by the three tests was related significantly to dry matter yield (DMY), but only in the first harvest, except for B1. Established critical P levels (CPLs) differed for TSP and PRs. In PR-fertilized soils, CPLs were 27, 17, and 12 mg P kg-1soil for Meh3, B1, and strip, respectively, and 42, 31, and 12 mg P kg-1soil, respectively, in TSP-fertilized soils. Thus, the strip resulted in a common CPL for TSP and PRs (12 mg P kg-1soil). This method can be used effectively in soils where integrated nutrient sources have been used, but there is need to establish CPLs for different crops. For cost-effective fertilizer P recommendations based on conventional soil tests, there is a need to conduct separate calibrations for TSP- and PR-fertilized soils.

2001 ◽  
Vol 58 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
José Francisco da Cunha ◽  
Ariel Francisco Candiotti Ventimiglia

Ten P fertilizers were collected (commercial fertilizers) or synthesized (experimental sources) in order to obtain single superphosphates varying in water and citrate solubility. A standard source of P was also produced by crystallization of the water-soluble fraction of a triple superphosphate. Eleven P sources were band applied to a medium textured Xanthic Hapludox, in Bahia, Brazil (low content of resin-extractable P) at a rate of 80 kg ha-1 of NAC + H2O (neutral ammonium citrate plus water) soluble P2O5, with soybean as the crop which was grown to maturity. A check plot (control) was included in the study. Three of the P sources [single superphosphate produced from Araxa phosphate rock (PR), low-grade single superphosphate produced from Lagamar PR and the standard source of P] were also applied at rates to provide 40 and 120 kg ha-1 of NAC + H2O soluble P2O5. Yield of soybean was evaluated by analysis of variance with mean comparison performed utilizing LSD lines, considering the P sources applied at a rate of 80 kg ha-1 of P2O5 + control. Regression procedures were used to study the relation between yield of soybean and rates of P2O5. The fertilizers tested performed equally well as a source of P for soybean. The level of water-soluble P did not influence fertilizer performance.


2011 ◽  
Vol 11 ◽  
pp. 1421-1441 ◽  
Author(s):  
E. W. Gikonyo ◽  
A. R. Zaharah ◽  
M. M. Hanafi ◽  
A. R. Anuar

Soil phosphorus (P) release capability could be assessed through the degree of P saturation (DPS). Our main objective was to determine DPS and, hence, P threshold DPS values of an Ultisol treated with triple superphosphate (TSP), Gafsa phosphate rocks (GPR), or Christmas Island phosphate rocks (CIPR), plus or minus manure. P release was determined by the iron oxide—impregnated paper strip (strip P), while DPS was determined from ammonium oxalate—extractable aluminum (Al), iron (Fe), and P. Soils were sampled from a closed incubation study involving soils treated with TSP, GPR, and CIPR at 0–400 mg P kg-1, and a field study where soils were fertilized with the same P sources at 100–300 kg P ha-1plus or minus manure. The DPS was significantly influenced by P source x P rate, P source x manure (incubated soils), and by P source x P rate x time (field-sampled soils). Incubated soil results indicated that both initial P and total strip P were related to DPS by exponential functions: initial strip P = 1.38exp0.18DPS, R2= 0.82** and total strip P = 8.01exp0.13DPS, R2 = 0.65**. Initial strip P was linearly related to total P; total P = 2.45, initial P + 8.41, R2= 0.85**. The threshold DPS value established was about 22% (incubated soil). Field soils had lower DPS values <12% and strip P was related to initial DPS and average DPS in exponential functions: strip P = 2.6exp0.44DPS, R2= 0.77** and strip P = 1.1DPS2— 2.4DPS + 6.2, R2= 0.58**, respectively. The threshold values were both at ≈8% and P release was 11–14 mg P kg-1. Results are evident that DPS can be used to predict P release, but the threshold values are environmentally sensitive; hence, recommendations should be based on field trials.


1983 ◽  
Vol 63 (1) ◽  
pp. 173-181 ◽  
Author(s):  
N. W. HOLT ◽  
G. E. WINKLEMAN

The magnitude and duration of response of bromegrass-alfalfa to a one-time application of phosphorus (P) fertilizer was studied at rates of P to 144 kg/ha which were applied in 1970 to a clay soil containing 5 μg/g sodium-bicarbonate-extractable P. All treatments produced residual effects which were reflected by increased forage yields, forage P content and forage uptake of P by bromegrass-alfalfa during the years 1972–1976. Forage yield response to applied P was curvilinear in 3 out of 5 yr while forage P and uptake of P increased in a linear relationship with applied P in all years. An annual application of 18, 10 and 16 kg/ha N, P and S, respectively, resulted in dry matter yields of 4110 kg∙ha−1∙yr−1 and when combined with the 1970 applications had no further significant effect on forage yields but the combinations did increase forage P and uptake of P. Soil sodium-bicarbonate-extractable P as determined each year 1972–1976 and in 1980 was proportional to applied P but the amount of available P decreased over this period. On average, the portion of alfalfa in the dry matter increased during the 1972–1976 period but the alfalfa content was not related to applied P. When amounts of nitrogen applied as part of the P fertilizer were over 36 kg/ha, the percentage of alfalfa in the stand was reduced until 1974.Key words: Phosphorus, bromegrass-alfalfa


Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 795 ◽  
Author(s):  
ICR Holford ◽  
BE Schweitzer ◽  
GJ Crocker

Measurements of phosphorus (P) sorption, isotopically exchangeable, KCl soluble and extractable P (Bray(1)) were carried out on limed and unlimed soils from eight pasture experiments on the Northern Tablelands of New South Wales at intervals of 1, 2 and 3 years after lime application. Lime increased soil pH by a minimum of 0.5 to a maximum of 1.55 units, and there were corresponding decreases in soluble aluminium and manganese. Lime decreased P sorptivity in every soil and at every sampling, but decreases were usually largest at the first sampling. They were attributed to the pH-induced increase in surface negative charge and the smaller increases in calcium concentrations of these freely drained soils, compared with undrained potted soils, of a previous glasshouse experiment. Isotopically exchangeable P was increased by the highest lime rate (5 t/ha) in all but one soil at the first sampling, while soluble P was increased by both lime rates in all soils. Increases in exchangeable P tended to decline at successive samplings, but increases in soluble P sometimes increased and sometimes decreased with time. In general, lime-induced increases in soluble P were consistent with decreases in P sorptivity, although the primary cause of the increases was probably the dissolution of iron and aluminium phosphates. All these changes were conducive to the increased plant availability and uptake of soil and fertilizer P.


1991 ◽  
Vol 31 (1) ◽  
pp. 99 ◽  
Author(s):  
DE Hibberd ◽  
PS Want ◽  
MN Hunter ◽  
J Standley ◽  
PW Moody ◽  
...  

At Emerald in central Queensland, dryland sorghum and sunflower were grown on a cracking clay soil (Vertisol) for 4 years and sorghum was grown in the sixth year, after an 18-month fallow. The initial bicarbonate-extractable soil phosphorus (P) concentration was 6 mg/kg in the 0-20 cm horizon. High analysis superphosphate (19.2% P) was broadcast at 0-180 kg P/ha in the first year, and banded rates of 0-20 kg P/ha were superimposed on the broadcast rates of 0-60 kg P/ha each year except in the fifth (fallow) year. Sorghum dry matter (DM) yields at anthesis, summed over 5 seasons, increased linearly (P<0.05) with both methods of P application, but significant (P<0.05) treatment differences occurred only after the 18 months of fallow. Total sorghum grain yields after 5 seasons fitted a quadratic reponse curve (P<0.05) with both application methods. Sunflower DM yields at anthesis increased significantly (P<0.05) with broadcast fertiliser in the first season only, but neither the rate nor the method of application of fertiliser affected seed yields over 4 seasons. Seed P concentrations for both crops were either unaffected or increased with increasing rates of fertiliser. Fertiliser P may not be needed for sunflower, but we recommend banding about 70 kg P/ha with sorghum at sowing over 5 years to ensure maximum yields. Based on extractable P values, the relative effectiveness of initial broadcast and incorporated P applications exceeding 40 kg/ha declined over the first 4 years, but then tended to remain steady at about 0.67. There was no consistent trend in relative effectiveness with time at the lower rates of P application.


1966 ◽  
Vol 66 (3) ◽  
pp. 351-357 ◽  
Author(s):  
W. Ellis Davies ◽  
G. ap Griffith ◽  
A. Ellington

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.


2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.


1970 ◽  
Vol 32 (1) ◽  
pp. 41-53
Author(s):  
YN Jolly ◽  
A Islam ◽  
SB Quraishi ◽  
AI Mustafa

The impact of various dilutions (2.5, 5, 10, 25 and 50%) of paint industry effluent on physico-chemical properties of soil and the germination, growth and dry matter productions of corn (Zea mays L.) and rice (Oryza sativa L.) have been studied. The effluent was acidic and had low BOD and COD values because of its low content of suspended solid. It contained high concentration of calcium, medium concentrations of nitrogen, sodium, potassium, sulphate, chloride and low concentrations of phosphorus, magnesium and bicarbonate. The trace element like Mn, Ni, Cu, Zn and Pb were measured in the μg L-1 level. On irrigation of soil with the effluent an increase in the water soluble salts, pH, electrical conductivity, cation exchange capacity, nitrogen, phosphorus potassium, sodium, calcium, magnesium and iron contents of the soil for effluent concentrations of 2.5, 5 and 10% were observed but all these parameters were found to decrease on treatment of the soil with the effluent concentration of 25% and above. The effluent of the lower concentrations (2.5, 5 and 10%) enhanced the growth of both crops. However, negative effects on seed germination, dry matter production and the yield of both crops were found for the effluent concentration of 25% and above. doi: 10.3329/jbas.v32i1.2441 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 41-53, 2008


2005 ◽  
Vol 62 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Rossini Mattos Corrêa ◽  
Clístenes Williams Araújo do Nascimento ◽  
Silvana Keely de Sá Souza ◽  
Fernando José Freire ◽  
Gleibson Barbosa da Silva

Crops in general make poor use of phosphorous fertilizer and, as a result, recommended rates and production costs are very high. Phosphorus can be made more readily available to plants by proper management of phosphate fertilization, selecting both, type of fertilizer and application method. This study was carried out to evaluate the efficiency of the natural Gafsa rock phosphate and the triple superphosphate on dry matter production and P uptake by corn plants cultivated in a greenhouse. Fertilizers were applied localized and broadcast/incorporated on to two soils with contrasting phosphorus capacity factors (PCF). Rock phosphate broadcast application was as efficient as triple superphosphate in increasing corn plant dry matter in the Tropudult, with lower PCF. This effect was not observed on the Haplustox, owing to the lower P solubility due to the higher Ca concentration in this soil. Triple superphosphate rates increased plant P uptake in both soils and for both application forms. Rock phosphate resulted in higher P-content in plants, but only for broadcast application on the Ultisol.


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