Phase Equilibria and Kinetics of Orthophosphate in Some Iraqi Soils

Al-Khateeb, Ismail K.; Raihan, M. J.; Asker, S. R.

doi:10.1097/00010694-198601000-00006

Cited by 14 publications

(5 citation statements)

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“…The presence of small amounts of pyrophosphate inhibits or retards nucleation and/or crystal growth of DCDP in either pure CaC03 or calcareous soils (EIZahaby and Chien, 1982;Amer et aI., 1985). Phosphate concentration, especially at low supersaturation, affects the kinetics of precipitation and the nature of the precipitate (AI-Khateeb et aI., 1986;Shaviv et aI., 1989) since it affects the Ca: P activity ratio. Hundal (1988) contended that P sorption in an alkaline soil followed a four-region Langmuir isotherm due to the successive formation of HA, P-TCP, OCP, and DCDP.…”

Section: Precipitation Products and Phosphate Potentialsmentioning

confidence: 99%

See 1 more Smart Citation

Soil and Fertilizer Phosphorus and Crop Responses in the Dryland Mediterranean Zone

Matar¹,

Torrent²,

Ryan³

1992

Advances in Soil Science

157

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Section: Precipitation Products and Phosphate Potentialsmentioning

confidence: 99%

“…Little research has been conducted in the region on P fertilizers per se. This was limited to incubation studies of pyrophosphate reactions in calcareous soils (AI-Khateeb et aI., 1986). Pyrophosphate rapidly hydrolizes in the soil to orthophosphate-the form in common P fertilizers.…”

Section: F Types Of Phosphorus Fertilizersmentioning

confidence: 99%

Soil and Fertilizer Phosphorus and Crop Responses in the Dryland Mediterranean Zone

Matar¹,

Torrent²,

Ryan³

1992

Advances in Soil Science

157

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“…Madrid, et al(1977) showed that the increase in utilization efficiency Received 10/5/2009Received 10/5/ accepted 20/9/ 2010 of phosphorus fertilizer by rye grass as the ratio of Mg/Ca increased by the incorporation of MgSO 4 .7H 2 O with dicalocium phosphate and octacalcium phosphate. Al-Khatteb et al(1986) found the formation of higher amount of dimagnesium phosphate and trimagnesium phosphate, if the ratio of Mg/Ca higher than 1.5 which caused the increase in phosphorus availability. Al-Kaysi and Saleem (1990) applied different ratios (0/0, 0/200, 50/150, 100/100, 150/50, 200/0 meq L -1 ) 0f Mg/Ca they indicated that the increase in the ratio of applied Mg/Ca caused an increase in phosphorus availability for plants.…”

Section: Introductionmentioning

confidence: 90%

The Role of Magnesium in Increasing of Phosphorus Fertilizer Efficiency and Wheat Yield

Rasul¹

2011

Mesopotamia Journal of Agriculture

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The study was conducted during the growing season 2003 to study the influence of four levels of P (0, 60, 100 and 140 kg ha -1 ) and four levels of Mg (0, 40, 80 and 120 kg ha -1 ) at two locations (Bakrajow and Kalar) on growth and yield of wheat and phosphorus fertilizer efficiency. The results indicated to the response of wheat to phosphorous fertilizer at Bakrajow location only. While the application of 40 kg Mg ha -1 caused significant increase in wheat yield at Bakrajow location only. The highest phosphorus fertilizer efficiency was 34.44% and 55.24% at Bakrajow and Kalar respectively while the Mg fertilizer efficiency was 7.6% and 22.8% at Kalar and Bakrajow respectively.

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“…Both P fertilizers can convert into various inorganic P fractions including soil Fe-P (especially in paddy soils with high Fe 2+ ) (Sah et al, 1989) and soil Al-P, which can account for 33 % of the total soil P in weathered soils (Margenot et al, 2017). Soil Ca 2 -P and Ca 8 -P could be also formed with P addition, especially in calcareous soils with pH higher than 7 (Al-Khateeb et al, 1986). In a previous study it was found that long-term application of Ca(H 2 PO 4 ) 2 increased soil IP fractions (Al-P, Fe-P, Ca 2 -P, Ca 8 -P and O-P) and total P (TP) concentra-tions in a calcareous soil (Wang et al, 2010), and another study showed that long-term Ca(H 2 PO 4 ) 2 addition decreased soil P availability due to fixation of P to the soil constituents (Xiong et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Exogenous phosphorus compounds interact with nitrogen availability to regulate dynamics of soil inorganic phosphorus fractions in a meadow steppe

Liu¹,

Wang²,

Wang³

et al. 2019

Biogeosciences

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Abstract. Here we investigated the effects of P compounds (KH2PO4 and Ca(H2PO4)2) with different addition rates of 0, 20, 40, 60, 80, and 100 kg P ha−1 yr−1 and NH4NO3 addition (0 and 100 kg N ha−1 yr−1) on soil labile inorganic phosphorus (IP) (dicalcium phosphate, Ca2-P), moderate-cycling IP, and recalcitrant IP fractions in a calcareous grassland of northeastern China. Soil moderate-cycling IP fractions, not readily available to plants but transforming into soil-available P quickly, include variscite (Al-P), strengite (Fe-P) and octacalcium phosphate (Ca8-P); recalcitrant IP fractions include hydroxylapatite (Ca10-P) and occluded P (O-P). Soil labile and moderate-cycling IP fractions and total P significantly increased with increasing P addition rates, with higher concentrations detected for KH2PO4 than for Ca(H2PO4)2 addition. Combined N and P treatments showed lower soil labile IP and moderate-cycling IP fractions compared to ambient N conditions, due to enhanced plant productivity. Moderate-cycling IP was mainly regulated by P addition and plant P uptake to further enhance labile IP and total P concentrations with KH2PO4 and Ca(H2PO4)2 addition. Soil labile IP was also directly and negatively affected by soil pH and plant P uptake with Ca(H2PO4)2 addition. Ca(H2PO4)2 addition significantly increased the soil recalcitrant IP (Ca10-P) fraction, while KH2PO4 addition showed no impact on it. A significant positive correlation was detected between soil labile IP, moderate-cycling IP fractions and soil Olsen-P which illustrated that labile IP and moderate-cycling IP fractions were important sources for soil-available P. Our results suggest that moderate-cycling IP fractions are essential for grassland P biogeochemical cycling and the chemical form of P fertilizer should be considered during fertilization management for maintaining soil-available P.

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Phase Equilibria and Kinetics of Orthophosphate in Some Iraqi Soils

Cited by 14 publications

References 0 publications

Soil and Fertilizer Phosphorus and Crop Responses in the Dryland Mediterranean Zone

Soil and Fertilizer Phosphorus and Crop Responses in the Dryland Mediterranean Zone

The Role of Magnesium in Increasing of Phosphorus Fertilizer Efficiency and Wheat Yield

Exogenous phosphorus compounds interact with nitrogen availability to regulate dynamics of soil inorganic phosphorus fractions in a meadow steppe

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