FATE OF PHOSPHORUS IN CALCAREOUS SOILS

1. By
M.Sc. (Agri.) Student
Deptt . of Soil Science & Agril. Chemistry

2. Index..
 Introduction
 Characteristics of calcareous soils
 Chemistry of phosphorus in calcareous soils
 Review of literature
 Conclusion
3

3. Introduction
Facts About Phosphorus
• The name comes from the Greek word
‘phosphoros’, which means bringer of
light, because phosphorus glows in the
dark.
• Phosphorus is a nonmetal, solid at room
temperature.
• It was discovered around 1669 by a
German chemist named Hennig Brandt
during an experiment where he was
attempting to change silver into gold.
• It is the 11th most abundant element and it
is found in all fertile soil and most natural
waters.
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4

4. Agricultural point of view
• Phosphorus (P) is the second most abundant macronutrient in
plants after nitrogen. The unique characteristic of P is its low
availability due to slow diffusion and high fixation in soils.
Hence P can be one of the major limiting factor for plant growth.
• In soils, it is mainly present in inorganic and organic forms.
Generally the concentration of P is ranges from 50 - 1500 ppm in
surface soils, while in organic matter rich soils it is present as
organic P complexes.
• It is most studied element but the least understood due to its
complex chemistry in the soil plough layer.
5

5. Pools of Soil Phosphorus
categorized into the following four groups :
(i) Phosphorus ions and compounds in the soil solution;
(ii) Phosphorus adsorbed on the surface of inorganic soil
constituents;
(iii) Phosphorus minerals, both crystalline and amorphous; and
(iv) Phosphorus as a component of soil organic matter.
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6. Soil PAvailable P
(<3% of total P)
Unavailable P
(>97% of total P )
Inorganic P
(15–80 %)
Organic P
( 20–85 %)
Adsorbed P
Mineral P
Inositol Phosphate
(10–55 %)
Phospholipids
(1–5%)
Nucleic Acids
(0.2–2.5%)
Phosphoprotein
(Trace)
Phosphosugars
(Trace)
7

7. 1-64
8

8. About Calcareous soils
• Calcareous soils has free calcium carbonate in their profile. These soils
cover more than 30% of the earth’s surface and their CaCO3 content
varies from a few percent to 95 %.
• The estimated area of calcareous soils is 228.8 m ha and covers 69.4%
of the total geographical area of the country mainly in Rajasthan,
Punjab, Haryana, Gujarat, UP, Maharastra, Karnataka, AP and part of
MP, Assam and some Union territories (Pal et al.,2000)
• It occurs mainly in arid and semi – arid zones, where their parent
material is rich in CaCO3 , pH of these soils is usually above 7 and may
be as high as 8.5.
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9

9. Characters of Calcareous soil
• The presence of CaCO3 in calcareous soils affects both physical as
well as chemical properties such as soil – water availability to
plants, surface crust, affect the chemistry and availability of N , P ,
K , Mg ,Zn , Cu , and Fe etc.
• Calcareous soils tend to be low in organic matter and available
nitrogen. The high pH also results in unavailability of phosphate in
these soils.
• The specific surface area of CaCO3 controls P fixation reactions in
calcareous soils. phosphorus replaces adsorbed bicarbonate ions
and hydroxyl ions when it is adsorbed by calcite.
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10

10. Chemistry of P in calcareous soils
Ca(H2PO4)2 + CaCO3 + H2O 2 CaHPO4
·2H2O + CO2
very less
soluble soluble
6 CaHPO4
·2H2O + 3 CaCO3 3 Ca3(PO4)2 + 3 CO2 + 5 H2O
less
soluble
3 Ca3(PO4)2 + CaCO3 3Ca3(PO4)2
.CaCO3
very
insoluble
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11

11. (listed in order of decreasing solubility)
 Dicalcium phosphate (DCP): CaHPO4
 Dicalcium phosphate dihydrate (DCPD): CaHPO4.2H2O
 Tricalcium phosphate (TCP): Ca3(PO4)2
 Octacalcium phosphate [Ca8H2(PO4)6.5H20]
 Hydroxyapatite (HA): Ca5(PO4)3.OH
 Fluorapatite (FA): Ca5(PO4)3F (least soluble)
Common P Minerals found in Neutral and Calcareous
Soils
12

12.  The Quantity of P sorbed on calcite depends largely on its surface
area
 Pure calcite has low surface area (1 to 2 m2/g)
 Soil calcite has surface area ranging from 16 to 200 m2/g
(due to dissolution, reprecipitation, and incorporation of impurities)
0 ppm P 10 ppm P 50 ppm P
Calcite Equilibrated for 10 Days, 1-64
13

13. fig.01:Effect of soil pH on P availability
14

14. Review of Literature
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15

15. Effect of incubation time on P
solubilization
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16

16. Figure 02: Effect of incubation time and fertilizer
sources on available P in calcareous soil
Khalid et al. 2011Saudi Arabia 1-64
17

17. Figure 03: Change of inorganic P concentration in soil solution during the
wheat crop in calcareous soil (Aridisol), without (−P) and with P fertilization
(+P, 35 kg P per ha), average of 2 years (1993–1995)
Rajaram et al. 2000Germany 1-64
18

18. Effect of applied P Dosage on crop
yield in calcareous soils
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19

19. Table 01: Effect of phosphorus on P concentration at
successive growth stages of groundnut (Pooled data)
Treatment P concentration (%)
45(DAS) 70(DAS) Kernel Shell
Phosphorus (kg P2O5/ha)
20 0.35 0.34 0.53 0.19
40 0.36 0.35 0.54 0.19
60 0.37 0.36 0.55 0.21
CD at 5% 0.006 0.006 0.011 0.005
RAO et al. 1997Udaipur
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20. Table 02: Effect of different levels of P on maize plant height, number
of cobs, grain and biomass yield as affected by in calcareous soil
P
(kg P2O5/ha)
Plant
height
(cm)
Cobs/plot
Grain yield
t/ha
Biomass
t/ha
0 180.6 81.0 5.43 9.85
45 195.3 83.6 6.40 11.92
90 213.9 93.3 6.87 13.50
135 217.6 100.3 7.99 13.51
180 219.9 103.6 8.18 14.00
CD at 5% 6.12 10.13 1.10 1.53
Davanagere, Karnataka Kumar et al. 20031-64
21

21. Table 03: Effect of interaction between rate of
soil P and Foliar P application on wheat yield
Soil application
(kg/ha)
Foliar application rate (kg/ha)
0 3 6 12 mean
T1- 0 3907.0 4961.3 5028.7 5136.7 4758
T2- 150 5548.7 5767.0 5893.7 6606.7 5953
T3-450 5861.7 6438.0 6444.7 7904.0 6661
mean 5105.8 5722.1 6184.0 6567.8
CD at 5% 1411
Hardi et. al. 2012Saudi Arabia 1-64
22

22. Table 04: Effect of Rate of P application on tillers m-2, grains
spike-1, 1000-grain weight and grain yield of wheat
P rate
(kg/ha)
Tillers/m2 Grains/spike 1000 grain
wt. (g)
Grain yeild
(Mg/ha)
T1-0 229.33 26.21 26.28 1.58
T2-47 271.71 31.11 31.92 3.33
T3-81 295.00 37.29 34.48 3.67
T4-111 307.38 39.01 36.25 3.94
CD at 5% 7.648 1.88 1.047 0.107
Rakesh et al. 2010Maharastra
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23

23. Table:05.Treatment details of AICRP-LTFE
T1 50 % NPK of recommended doses in G’nut-Wheat sequence.
T2 100 % N P K of recommended doses in G’nut –wheat sequence.
T3 150 % N P K of recommended doses in G’nut -wheat sequence.
T4 100 % N P K of recommended doses in G’nut -wheat sequence + ZnSO4 @ 50
kg ha-1 once in three year to G’nut only.
T5 N P K as per soil test
T6 100 % N P of recommended doses in G’nut -wheat sequence.
T7 100 % N of recommended doses in G’nut -wheat sequence.
T8 50 % N P K of recommended doses + FYM @ 10 t/ha to G’nut and 100 % N P
K to wheat.
T9 Only FYM @ 25 t ha-1 to G’nut only.
T10 50 % N P K of recommended doses + Rhizobium + PSM to G’nut and 100 % N
P K to wheat.
T11 100 % N P K of recommended doses in G’nut -wheat sequence (P as SSP)
T12 Control
24

24. Table:06.Temporal variation in inorganic phosphorus
as influenced by different nutrient management in
groundnut-wheat sequence.
Junagadh Rajani et al. 201025

25. Table 07;Temporal variation in total phosphorus as influenced by
different nutrient management in groundnut-wheat sequence
Treatments Total-P (ppm)
1st year 4th year 8th year Pooled
T1 945.25 1555.62 1242.62 1247.83
T2 842.25 2039.37 1687.37 1523.00
T3 927.12 1633.50 1638.25 1399.63
T4 779.00 1702.12 1486.87 1322.67
T5 744.50 1337.00 1526.25 1202.58
T6 902.00 1284.37 1511.25 1232.54
T7 1406.87 1365.37 1280.50 1350.92
T8 927.12 2112.50 1417.37 1485.67
T9 887.12 1401.62 1456.12 1248.29
T10 1045.25 1546.50 1518.75 1370.17
T11 895.25 1766.25 1451.50 1371.00
T12 948.25 1513.50 1400.25 1300.67
C.D. (P=0.05) 241.09 392.955 NS NS
Rajani et al. 2010Junagadh 26

26. Effect of FYM on P solubilization
in calcareous soils
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27. • Organic ligands affect P sorption- they compete with ortho-P for
similar sites on the surface of oxides.
• Organic matter may also chelate metals and prevent reactions
between metals and P.
Organic Matter and P Interactions
PO4
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28

28. Table 08: Effect of combined application of phosphorus and farmyard
manure application on the performance of wheat in calcareous soils
Phosphorus and
FYM Levels
Plant height (cm) 1000-grain
weight (g)
Grain yield (kg
ha-1)
Biological yield
(kg ha-1)
P1 FYM1 82.28 37.8 3.46 8.72
P1 FYM2 89.63 38.64 3.49 8.10
P1 FYM3 90.26 38.71 3.58 8.89
P2 FYM1 91.05 39.48 3.65 9.14
P2 FYM2 92.98 39.57 3.70 9.28
P2 FYM3 92.95 39.66 3.83 9.58
P3 FYM1 93.59 40.065 4.09 10.12
P3 FYM2 94.80 40.18 4.28 10.57
P3 FYM3 96.00 40.97 4.36 10.74
CD at 5% 0.135 0.16 0.032 0.028
Ahmad et al. 2007Faisalabad
F1=120, F2=180 and F3=240 (kg /ha)P1=60, P2=90 and P3=120 (kg P2O5/ha)
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29. Table 09: Effect of organic manure and elemental sulphur on the distribution of
available-P from rock phosphate throughout calcareous soil columns
OM Sulphur P rate
(kg/ha)
Soil column depth (cm)
0-5 5-10 10-15
mg/kg
0 % OM
control
0 3.87 3.39 4.90
30 3.44 3.05 5.07
1.0% S
0 4.97 5.26 6.29
30 5.43 4.80 5.75
3% OM
control
0 8.99 8.00 8.99
30 14.61 16.09 17.82
1.0 % S
0 15.10 13.44 15.10
30 24.55 27.03 29.93
6% OM
control
0 18.12 16.13 18.12
30 29.46 32.43 35.92
1.0% S
0 19.96 17.77 19.96
30 32.46 35.73 39.57
Al-oud S. 2011Russia
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30. Table 10: Transformation of P into its various fractions as
influenced by incubation time and organic matter levels
Organic matter
levels (%)
P fractions (mg/kg)
Ca-P Org-P Olsen's-P
28 days period
T1- 0% 548.8 92.4 13.3
T2- 2.5% 546.9 123.1 23.3
T3- 5.0% 545.2 146.7 28.2
CD at 5% 1.41 3.10 0.42
Patel et al. (1992)Gujarat
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31. Treatment
Organic manure (ha-1)
P concentration (%)
45(DAS) 70(DAS) Kernel Shell
T1-Control 0.35 0.33 0.52 0.19
T2-FYM (10t) 0.37 0.35 0.55 0.20
T3-Poultry manure (5t) 0.37 0.36 0.56 0.22
CD at 5% 0.006 0.006 0.011 0.005
Udaipur RAO et al. 1997
Table 11: Effect of organic manure on P concentration at
successive growth stages of groundnut (Pooled data)
32

32. Figure 04: Effect of vermicompost on WSP content of rock
phosphate during 60 days of incubation.
(V1-0%, V2-15%)
Iran Hasin et al. 20091-64
33

33. Figure 05: Changes in phosphorus recovery as Olsen-P (%) over time
after amended with phosphorus (p), phosphorus+manure (P+OM) and
manure treated Calcareous soils.
Hasin et al. 2008Iran
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34. Role Of Phosphate Solubilizing Micro-
organisms on Improving Phosphorus
solubilization
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35

35. Bacillus
Pseudomonos
Aspergillus awamori
PHOSPHATE SOLUBILIZING MICRO-ORGANISMS
Phosphate Solubilizing Bacteria:
Phosphate Solubilizing Fungi and phosphorus Mobilizers:
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36. Table 12: Effects of E. agglomerans (PSRB) and G.
Etunicatum (AMF) inoculation on tomato plant growth and P
uptake (75 days after inoculation) in calcareous soils.
Treatments Shoot
dry
weight
(g/plant)
Root dry
weight(g/plant)
Total P(g/plant)
Shoots Roots
T1- CONTROL 42.21 4.29 116.46 11.9
T2- PSRB 48.49 5.10 125.26 13.6
T3- AMF 47.62 5.57 120.94 13.4
T4- PSRB+AMF 54.56 6.77 134.41 16.7
CD at 5% 1.96 0.53 9.85 -
Jordan et al. 1998Colombia
1-6437

37. Table 13: Phosphorus fractions (mg P/kg soil) and Enzymes in
the root compartment of wheat plants grown in calcareous
soils under different treatments
Treatment Org. P
(mg/kg
soil)
Olsen-P
(mg/kg soil)
Acid
phosphatase
(EU X 10-3)
Alkaline
phosphatase
(EU X 10-3)
T1- Inorg. P- VAM 357 163 8.8 0.8
T2- Inorg. P+ VAM 341 171 9.6 0.9
T3- Org. P-VAM 454 59 10.4 0.9
T3- Org. P+ VAM 424 71 10.7 1.2
CD at 5% 9.73 8.32 1.01 -
Inorganic P as Ca(H2P04 )2 and organic P as Na-phytate applied at 200 mg P /kg-soil.
Jagadis et al.2000Germany 38

38. Table 14: Effect of P application, PSB and FYM on different
forms of P (ppm) at 8th week of incubation
Treatment Al-P Fe-P Occl-P Ca-P
T1: 150 mg KH2PO4 /kg soil 39.30 59.91 94.02 238.52
T2: 150 mg KH2PO4 /kg soil + PSB 39.04 57.94 92.57 234.48
T3: 150 mg KH2PO4 /kg soil + FYM 39.03 57.40 91.49 232.29
T4: 150 mg KH2PO4 /kg soil + PSB + FYM 38.75 52.91 90.50 231.25
CD at 5% 1.12 1.42 1.31 0.98
Ravi et al. 2015Raichur
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39. Figure 06: Effect of incubation of Thiobacillus thiooxidans
on WSP content of rock phosphate during 60 days of
incubation
(non-inoculated B1 and inoculated B2 treatments)
Hasin et al. 2009Iran 1-64
40

40. Effect of different management
practices
1-6441

41. Table 15: Total P uptake by wheat (kg/ha) as influenced
by fertigation technique at different CaCO3 level in soil.
Treatments
(Kg P2O5 /ha)
CaCO3 (%)
6 9 13
T1- P0 (Control) 6.6h 4.4j 2.9k
T2- P100 (Broadcast) 12.3c 7.8g 5.7j
T3- P50 (Fertigation) 11.2d 7.8g 6.6h
T4 - P75 (Fertigation) 13.1b 8.7f 7.6g
T5- P100 (Fertigation) 16.6a 10.4e 8.9f
Pakistan Khan et al. 20111-6442
Means followed by similar letters do not differ significantly from each other at 5% level by
DMR test

42. Table 16: Effect of different methods of phosphorus fertilizer
application on yield and yield components of wheat crop in
calcareous soils
Treatments Germination
(%)
Plant
height
(cm)
Fertile tillers
(m2)
Grains per
spike
Grain yield
(t /ha)
T1-(Control) 80.45 95.50 306 26.70 3.53
T2-(P2O5 broadcast
at sowing time)
81.23 108.50 346 32.10 4.21
T3-(P2O5 side
drilling)
82.15 110.25 356 41.50 5.08
T4-(P2O5broadcast
at first irrigation)
79.58 101.50 398 32.40 4.25
T5-(P2O5 mix with
seed of wheat)
80.69 107.00 433 33.20 5.03
CD at 5% NS 4.05 36.00 1.89 0.73
Das et al. 2009Bihar 1-64
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43. Table 17:Soil phosphorus availability and uptake by groundnut
under different land management options in calcareous vertisols
Treatment details
Olsen’s- P Resin-P Biomass P Uptake
(mg/kg) (mg/kg) (g/pl.) (mg/pl.)
T1- Conventional system 8.84 4.56 10.56 24.43
T2- Broad bed and furrow (BBF)
(100-40 cm)
11.77 5.94 10.19 24.95
T3- Ridge and furrow system 12.66 4.08 8.39 19.11
T4- Raised (Narrow) bed and furrow
(60-30 cm)
15.87 5.05 9.06 21.24
T5- Conventional system with PM 21.70 11.98 12.74 31.73
T6- Ridge and furrow system with PM 35.15 16.63 12.99 32.16
T7- Raised (Narrow) bed and furrow
(60-30 cm) with PM
39.33 19.59 15.06 40.36
CD at 5% 4.86 2.42 1.81 4.02
DGR. Junagadh Yadav et al. 2012
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44. Effect of different amendments on P
uptake by crop
1-6445

45. Table 18: Effect of rock phosphate and superphosphate in
an amended Calcareous soil on yield of wheat(2 year data)
Treatments Wheat grain yield (q/ha)
P0(control) P1 P2 P3 Mean
T1-(control) 17.50 23.97 21.32 22.82 21.40
T2-(2t pyrite/ha) 19.22 24.57 21.30 24.77 22.47
T3-(20t sulphitation
pressmud/ha)
21.45 25.57 25.70 25.36 24.51
T4-(10t sulphitation
pressmud + 1t
pyrite/ha)
20.87 26.85 25.60 25.70 24.66
Mean 19.76 25.14 23.48 24.66
CD at 5% (A x B) 3.80
Bihar Singh et al. 2000
P1 - 50kg P2O5/ha as SSP; P2 - 50kg P2O5/ha as MRP; P3 - 12.5kg P2O5 as SSP + 37.5kg P2O5 as MRP
46

46. Table 19: Effect of treatments on mean P uptake by
wheat in amended calcareous soils.
Treatments P uptake (kg/ha)
P0 (Control) P1 P2 P3 Mean
TI- (Control) 7.72 11.14 9.18 9.19 9.31
T2- (2t pyrite/ha) 7.91 11.41 11.97 12.41 10.93
T3- (20t sulphitation
pressmud/ha)
9.73 12.70 12.78 10.24 11.36
T4- (10t pressmud + 1t
pyrite/ha)
9.69 13.55 12.54 12.60 12.10
Mean 8.76 12.20 11.62 11.11 -
CD at 5% (TxP) 2.20
P1 - 50kg P2O5/ha as SSP
P2 - 50kg P2O5/a as MRP
P3 - 12.5kg P2O5 as SSP + 37.5kg P2O5 as MRPBihar Singh et al. 200047

47. Table 20:Effect of pyrite and FYM amended phosphatic
fertilizers on yield and P uptake by wheat
Treatments Uptake of P (kg/ha) Yield (q/ha)
Grain Straw Total Grain Straw
T1: control 3.2 5.9 9.1 32.5 71.4
T2 : 50kg P2O5/ha as TSP 4.2 7.8 12.0 36.2 77.1
T3 : T2 + pyrite 6.9 12.5 19.4 44.8 89.8
T4 : T2 + FYM 5.7 11.3 17.0 41.1 86.3
T5 : 50 kg P2O5/ha as MRP 3.8 6.6 10.0 35.0 73.6
T6 : T5 + pyrite 4.4 8.0 12.4 38.5 80.1
T7 : T5 + FYM 6.4 11.7 18.1 43.1 89.0
CD at 5% 1.2 3.3 2.3 4.6 8.5
Bihar Prasad et al. 19991-6448
Pyrite- 500kg, FYM -100q,

48. Table 21: Effects of P treatments on shoot dry weight and total P in
shoot dry biomass of corn grown in a calcareous soils
P-sources Shoot dry
weight(gm/plant)
Total P in shoot dry
weight (mg/plant)
TI-Control 7.23 5.32
T2-RP 7.36 5.43
T3-Nbiof-1 7.43 5.58
T4-Nbiof-2 7.79 5.73
T5-Nbiof-3 8.22 6.11
T6-Biof-1 7.58 5.94
T7-Biof-2 8.05 6.47
T8-Biof-3 8.83 7.06
T9-TSP 9.81 7.55
CD at 5 % 1.23 1.45
Biof = rock phosphate plus sulfur inoculated with Thiobacillus, and NBiof = rock phosphate plus
sulfur without Thiobacillus. (S-1= 10%, S-2=15%, S-3=20%). TSP-300kg/ha, RP-200kg/ha
Iran Besharati et al.2007
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49. Table 22: Effect of organic acids on the distribution of available-P in
calcareous soil columns
Treatments
(%)
P rate
(kg/ha)
Soil column depth (cm)
0-5 5-10 10-15
available-P (mg/kg)
Oxalic acid
(0.1)
0 8.94 9.98 9.92
30 11.26 11.49 13.17
Oxalic acid
(0.2)
0 9.31 10.33 9.11
30 13.48 14.92 14.13
EDTA (0.1) 0 6.68 6.41 6.28
30 9.89 10.29 12.18
EDTA (0.2) 0 10.40 9.72 10.10
30 10.19 11.19 14.62
Citric acid (0.1) 0 8.81 8.47 7.19
30 11.76 9.90 11.54
Citric acid (0.2) 0 8.74 7.87 7.56
30 8.05 11.05 10.64
AL-OUD. 2011Russia
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50

50. Table 23: Effect of different treatments on total P content (kg/ha)
of broad bean plants (combined data of two seasons)
Treatments Total Phosphorous content (kg/ha)
Seed Straw Total
T1- SP 21.81 14.02 35.83
T2- RP 9.93 7.52 17.45
T3- RP+ ES 18.74 12.29 31.02
T4- RP + PSB 14.67 10.24 24.90
T5- RP + OM 25.29 17 42.29
T6- RP + PSB +ES 31.52 19.19 52
T7- RP + ES + OM 39.48 23.07 62.55
T8- RP + PSB + OM 35.38 20.79 56.17
T9- RP + PSB + OM + ES 46.05 25.21 71.26
CD at 5% 1.57 1.67 2.36
Ahmed . 2013Egypt 51
SP - 357kg/ha, RP-192 kg/ha, ES - 476kg/ha, OM- 6t/ha

51. Table 24: Effect of rock phosphate, SSP and spent wash on
Dry matter yield (g/pot) of shoot and Roots of sorghum taken
at 45 and 90 DAS
Treatments Dry matter accumulation Root Biomass
45 DAS 90DAS
T1- Control 9.3 12.4 7.7
T2- RP 9.4 14.1 8.4
T3- SW 7.7 16.5 10.0
T4- RP+SW(1:1) 7.9 20.8 10.8
T5- SSP 12.3 18.4 10.4
CD at 5% 1.26 0.79 1.15
Kumari et al.2012Haryana
RP- 806mg/kg soil, SSP- 940mg/kg soil, Spent Wash- 800ml/ kg soil
52

52. Figure 07: Effect of sulfur application on WSP
content of rock phosphate during 60 days of
incubation.
(S1 0%, S2 10%, and S3 20%)
Hasin et al. 2009Iran
1-646053

53. Effect of other nutrients on P forms
and uptake by crop
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54

54. Table 25:Effect of N, P and K Dose on P uptake by wheat at
harvesting stage
Treatments
(NPK kg/ha)
P uptake (mg/g)
Grain Straw Total
T1- N0P0K0 1.40 1.33 2.73
T2- N180P0K0 3.87 3.66 7.53
T3- N180P17.5K0 6.91 7.81 14.7
T4- N180P35K0 8.97 10.2 19.2
T5- N180P17.5K33.2 8.75 10.4 19.2
T6- N180P35K33.2 10.4 13.0 23.4
CD at 5% 1.07 1.21 -
Punjab Sharma et al. 2007
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55

55. Table 26 :Changes in P forms(kg/ha) in soil at
Harvesting stage of Wheat
Treatments
(NPK kg/ha)
P forms(kg/ha)
Olsen-P Saloid-P Ca-P Total-P
T1- N0P0K0 5.75 6.61 184 445
T2- N180P0K0 3.63 5.74 175 392
T3- N180P17.5K0 13.7 6.61 227 502
T4- N180P35K0 19.6 8.43 204 547
T5- N180P17.5K33.2 12.2 7.51 150 473
T6- N180P35K33.2 17.6 8.25 158 502
CD at 5% 1.24 1.57 10.8 22
Punjab Sharma et al. 2007
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56. Conclusion
In calcareous soils, recovery of phosphorus by
crop plant is usually very low due to high P fixation
by lime.
Hence the application of phosphatic fertilizers
along with PSM, organic manures, acidulates etc.
will reduce the applied P fixation, which leads to
better phosphorus solubilization and acquisition by
the crop plants resulted in higher crop yield.
Practices like land and water management will
also greatly altered the availability as well as
acquisition of soil phosphorus for plant nutrition.
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