Use of partially acidulated rock phosphate as a possible means of minimising phosphate fixation in acid soils

1970 ◽  
Vol 33 (1-3) ◽  
pp. 225-234 ◽  
Author(s):  
N. Panda ◽  
U. K. Misra
2021 ◽  
Author(s):  
Rajendra Prasad ◽  
Yashbir Singh Shivay

Phosphorus is a major plant nutrient obtained from non-renewable phosphate rock, which is not much available in India. Over and above in this its recovery efficiency in crops hardly exceeds 15-20 per cent. Utmost care is therefore required in its use. Phosphorus applied to soil gets fixed by the formation of insoluble reaction products by reacting with Fe and Al in acid soils and with calcium in saline and alkaline soils. Two techniques used for identification of reaction products are X-ray diffraction and solubility product principle. In addition, phosphate ions are also held on Fe and Al hydroxides by anion exchange. The reaction products identified are variscite and strengite minerals in acid soils and dicalcium phosphate and hydroxy apatite in calcareous soils. Methods to increase phosphorus recovery by crops include: 1) addition of organic matter to soils; 2) addition of sulphur to compost or to ground rock phosphate or directly to soil and use of phosphorus solubilising organisms including VAM/AM along with ground rock phosphate.


1951 ◽  
Vol 2 (4) ◽  
pp. 377 ◽  
Author(s):  
AJ Anderson ◽  
KD McLachlan

A study was made of the residual effect of superphosphate applied to pasture on acid soils on the Southern Tablelands of New South Wales. The effect of the superphosphate on the development of clover and subsequent changes in soil fertility and development of grass was examined. Only a limited proportion of the phosphorus applied was taken up by the pasture over the period of the experiments, but the evidence obtained suggests that this cannot be ascribed merely to phosphate fixation in the soil. The residual phosphorus was little, if any, less effective than current dressings over a number of years. The total yield of pasture was dependent almost entirely on the amount of superphosphate applied, and frequency of application had little or no effect on the total yield. A single dose at the commencement of the trials was as effective in increasing the total yield and the uptake of phosphorus as were annual dressings. High fertility and grass dominance were achieved by heavy annual dressings of superphosphate or by application of the bulk of the phosphorus in the early years. Lighter annual dressings resulted in clover dominance. Some advantages of heavier, less frequent application of superphosphate are discussed. Competition for phosphorus was an important factor in suppression of the clover by the grass. Evidence was presented in support of a hypothesis that grass or clover dominance is dependent both upon the vigour and fertility requirements of the species and upon the relation between the nitrogen demand of the pasture unit and the soil nitrogen status.


1956 ◽  
Vol 48 (1) ◽  
pp. 74-103 ◽  
Author(s):  
G. W. Cooke

The results of over 400 field experiments testing different kinds of phosphate fertilizers are summarized and are discussed with special reference to the reactions of the soils used. The classifications were:‘very acid’ soils—pH below 5·5, ‘acid soils’— pH 5·6 to 6·5, neutral soils—pH over 6·5. All comparisons are made in terms of fertilizers supplying the same amounts of total phosphorus.In war-time experiments Gafsa and Morocco rock phosphates were about two-thirds as efficient as superphosphate for swedes and turnips grown on very acid soils. In 1951–3 experiments on very acid and acid soils Gafsa phosphate was practically equivalent to superphosphate for swedes, but for potatoes it was as effective as only one-third as much phosphorus supplied as superphosphate; on neutral soils Gafsa phosphate was useless. For establishing grassland on acid soils Gafsa and Morocco phosphate were equivalent to about onethird as much phosphorus supplied as high-soluble basic slag. Rock phosphates were somewhat more effective for promoting growth of established grassland but they remained inferior to high-soluble basic slags and to superphosphate. Curacao rock phosphate was roughly equivalent to Gafsa phosphate for swedes and grass. Florida pebble phosphate was much less effective and was judged unsuitable for direct application. Mixtures of rock phosphate with superphosphate were not more efficient than equivalent amounts of the separate components used correctly.Silicophosphate was practically as effective as superphosphate for swedes grown on very acid and acid soils; it was less efficient on neutral soils. For potatoes silicophosphate was nearly as effective as superphosphate on very acid soils; it was much less efficient on acid and neutral soils. Silicophosphate was roughly equivalent to high-soluble basic slag for grassland.Mixtures of superphosphate with lime, serpentine, and low-grade basic slag were prepared, most of the water-soluble phosphorus being converted to insoluble forms. In experiments on swedes and potatoes these basic superphosphates were not superior to untreated superphosphate. For establishing grassland on very acid soils, the mixtures were slightly superior to ordinary superphosphate.Dicalcium phosphate was practically equivalent to superphosphate for swedes on all groups of soils. For potatoes dicalcium phosphate was more efficient than superphosphate on very acid soils, on less acid and neutral soils it was inferior to superphosphate.


2007 ◽  
Vol 9 (1) ◽  
pp. 10-15
Author(s):  
S Djuniwati ◽  
H.B Pulunggono ◽  
Suwarno .

One of the problems of acid soils such as Latosol is very low in P-availabi/ity due to high P-j'vcation in those soils. Sincesoils is deficiency of P, adaptation of plants and microorganisms to overcome deficiency of P in soil is by producing phosphatase. Phosphatase. is an enzyme that able to catalize transformation of organic P to inorganic P, and produced by plant roots, residual of plants and microorganisms. Organic mailer as a source of P besides N and energy formicroorganisms, and then rock phosphate as an alternative P fertilizer were used in this research. The objective of theresearch was to study the effect of organic matter (Centrocema pubescent) and rock phosphate application on phosphataseactivity and P fraction of Latosol soil from Darmaga, Bogor. The experiment was designed by completely randomized designwith two factors and three replications. The first factor was application of organic matter with the rate of 0, 2.5, and 5 %, and the second factor was application of rock phosphate with the rate of 0, 20, and 40 ppm P. Soil equivalent to four hundred grams of oven dried soil, organic matter, and rock phosphate were mixed based on the treatments of the experiment, and were placed in plastic pots, and then were incubated for 8 weeks period After incubation period, the soil were air dried and analyzed for phosphatase activity, available P, and organic and inorganic P. The result showed that organic mailer increased activities of acid and alkaline phosphatase, organic and inorganic-P of soil. On the other hand, rocle phosphate increased inorganic P but decreased activities of acid phosphatase,. Application of organic matter or rock phosphate on activity of acid phosphatase was higher (2.3-2.6 times) than on alkaline phosphatase. There was no effect of combinationbetween organic matter and rock phosphate on the activity of phosphatase and organic/inorganic P. Combination betweenorganic matter and rock phosphate Significantly affected available P. In each rates of rock phosphate given, the increasing rate of organic matter increased available P in their interactions, on the contrary, in each rates of organic matter, the increasing rate of rock phosphate did not affect available P in their interactions. However it was tended to decrease in therate of 40 ppm P.


Author(s):  
Debasis Sarangi ◽  
Dinabandhu Jena ◽  
Gour Hari Santra

To find out the effect of low grade Udaipur rock phosphate on yield and nutrient dynamic in groundnut- maize cropping system, a field experiment was conducted in a randomized block design with three replications and eight treatments consisting of Udaipur rock phosphate (URP), single super phosphate (SSP) alone or in combinations with different ratios including phosphorus control from 2013-14 to 2015. The soil has a loam texture, a pH of 5.18, low available nitrogen and medium phosphorus and potassium. The highest maize equivalent yield of 6293 kg ha-1 and relative agronomic efficiency (RAE) of 159% was recorded in SSP+ lime (0.2LR) treatment followed by URP+SSP (1:1). Combined application of SSP+ lime recorded higher P, Ca, Mg and S uptake by groundnut-maize cropping system. When the crops received URP+SSP mixture in 1:1 ratio, the RAE values were increased above the standard SSP treatment (T3) being 102% for groundnut, 105% for maize and 103% for groundnut-maize cropping system. The yield in URP+SSP mixture (1:1) was higher than for the SSP treatment, but the difference was not statistically significant (P > 0.05). Thus, combined application of URP+SSP mixture (1:1) can safely be recommended in acid soils for short duration crops like maize and groundnut as against the more costly water soluble SSP fertilizer.


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

1991 ◽  
pp. 533-538 ◽  
Author(s):  
K. M. Krishnappa ◽  
S. Panchaksharaiah ◽  
K. M. S. Sharma ◽  
T. S. Vageesh

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