The agronomic effectiveness of reactive rock phosphate, partially acidulated rock phosphate and monocalcium phosphate in soils of different pH

1993 ◽  
Vol 34 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Vijay Kumar ◽  
R. J. Gilkes ◽  
M. D. A. Bolland
Keyword(s):  
Rock Phosphate ◽  
Agronomic Effectiveness ◽  
Monocalcium Phosphate ◽  
Partially Acidulated Rock Phosphate

Agronomic effectiveness of rock phosphate combined with nitrogen sources in spot application: A pot experiment

2017 ◽  
Vol 180 (5) ◽  
pp. 585-593 ◽  
Author(s):  
Rafael V. Valadares ◽  
Reinaldo B. Cantarutti ◽  
Edson M. Mattiello ◽  
Rogério F. Vieira
Keyword(s):  
Rock Phosphate ◽  
Nitrogen Sources ◽  
Pot Experiment ◽  
Agronomic Effectiveness

Efficacy of phosphate solubilizing Actinobacteria to improve rock phosphate agronomic effectiveness and plant growth promotion

Rhizosphere ◽  
2021 ◽  
Vol 17 ◽  
pp. 100284
Author(s):  
Abdoulaye Soumare ◽  
Kenza Boubekri ◽  
Karim Lyamlouli ◽  
Mohamed Hafidi ◽  
Yedir Ouhdouch ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Rock Phosphate ◽  
Growth Promotion ◽  
Agronomic Effectiveness ◽  
Phosphate Solubilizing

DIFFUSION OF 32P FROM PARTIALLY ACIDULATED ROCK PHOSPHATE

Soil Science ◽  
1977 ◽  
Vol 123 (3) ◽  
pp. 203-206 ◽  
Author(s):  
TERRY J. LOGAN ◽  
EUGENE O. McLEAN
Keyword(s):  
Rock Phosphate ◽  
Partially Acidulated Rock Phosphate

The effect of rock phosphate properties on the extent of fertilizer dissolution in soils

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 209 ◽  
Author(s):  
JC Hughes ◽  
RJ Gilkes
Keyword(s):  
Rock Phosphate ◽  
High Availability ◽  
Unit Cell ◽  
Dicalcium Phosphate ◽  
Phosphate Fertilizers ◽  
Rock Phosphates ◽  
Monocalcium Phosphate ◽  
Rate Of Dissolution

Two soils, a West Australian Petroferric Udipsamment (WA4) and a Colombian Typic Haplustox (SA21) were incubated for up to 31 days with 23 phosphate fertilizers. These comprised 18 apatitic rock phosphates, three calcined rock phosphates, monocalcium phosphate and dicalcium phosphate. The fertilizers were mixed through the soils at rates of addition between 0.37 and 37 mg g-' soil. The extent and rate of dissolution of fertilizers were measured by determining changes in Ca using the ACa technique. Most dissolution generally occurred within one day for all fertilizers. The proportion of fertilizer that dissolved decreased with increasing rate of addition, and this proportion differed greatly between fertilizers (1-43% in WA4, 2-72% in SA21). All fertilizers dissolved to a greater extent in the Colombian soil. Calcined (1500�C) Queensland rock phosphate was the most soluble of the rock phosphates, which is consistent with its high availability to plants. The calcined iron-aluminium rock phosphates (Calciphos, Phospal) dissolved to a smaller extent than most of the apatitic rocks. The CaO/P2O5 ratio of the apatitic rock phosphate fertilizers was a slightly better predictor of the extent of dissolution than the apatite unit cell a dimension, although neither explained more than 60% of the variance. The present results are consistent with the accepted reactivity scale for the apatitic fertilizers, but the amount of each fertilizer which dissolved depended greatly on the soil to which it was applied.

Response of subterranean clover to rock phosphates as affected by particle size and depth of mixing in the soil

1974 ◽  
Vol 14 (70) ◽  
pp. 649 ◽  
Author(s):  
AM Alston ◽  
KW Chin
Keyword(s):  
Particle Size ◽  
Dry Matter ◽  
Rock Phosphate ◽  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Phosphorus Concentration ◽  
Dry Matter Yield ◽  
Rock Phosphates ◽  
Monocalcium Phosphate ◽  
Christmas Island

Samples of Christmas Island and Florida rock phosphates with different particle size ranges were applied to a phosphorus-deficient acid sandy soil. The rock phosphates were compared with monocalcium phosphate at various levels of addition of phosphorus. The fertilizers were mixed uniformly with either the top 1, 5, or 10 cm of the soil. Dry matter yield and phosphorus uptake in the tops of subterranean clover (Trifolium subterraneum) and the distribution (by weight) of the roots in the soil were determined. Monocalcium phosphate produced higher dry matter yields (tops and roots) than rock phosphates, even when the latter were applied in amounts containing four times the amount of phosphorus added as monocalcium phosphate. The concentration and uptake of phosphorus in the tops was also higher when monocalcium phosphate was applied, although the difference in concentration decreased as the plants matured. Dry matter yield and phosphorus concentration in the clover tops were increased by increasing the fineness of grinding of rock phosphate and by increasing the depth of mixing with the soil. Increasing the depth of mixing also produced a greater weight and more even distribution of roots. The yield of tops and roots was unaffected by the depth to which monocalcium phosphate was mixed, although shallow placement concentrated the distribution of the roots near the soil surface. Florida rock phosphate was a better source of phosphorus for subterranean clover than Christmas Island rock when the samples were coarsely ground, but both rocks were equally effective when ground to give 70 per cent < 100 mesh B.S.S.

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