“Phosphorus Dynamics in Calcareous Soils”

ByDileep Kumar R.

M.Sc. (Agri.) StudentDeptt . of Soil Science & Agril.

Chemistry

Index.. Introduction

Characteristics of calcareous soils

Chemistry of phosphorus in calcareous soils

Review of literature

Conclusion

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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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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

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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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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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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.10

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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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(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

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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, 13

fig.01:Effect of soil pH on P availability

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Review of Literature

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Effect of incubation time on P solubilization

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Figure 02: Effect of incubation time and fertilizer sources on available P in calcareous soil

Khalid et al. 2011Saudi Arabia 17

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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. 2000Germany18

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Effect of applied P Dosage on crop yield in calcareous soils

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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 20

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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 9.8545 195.3 83.6 6.40 11.9290 213.9 93.3 6.87 13.50135 217.6 100.3 7.99 13.51180 219.9 103.6 8.18 14.00

CD at 5% 6.12 10.13 1.10 1.53Davanagere, Karnataka Kumar et al. 200321

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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. 2012 Saudi Arabia22

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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. 2010 Maharastra 23

Table:05.Treatment details of AICRP-LTFET1 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 testT6 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

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Table:06.Temporal variation in inorganic phosphorus as influenced by different nutrient management in groundnut-wheat sequence.

Junagadh Rajani et al. 201025

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 PooledT1 945.25 1555.62 1242.62 1247.83T2 842.25 2039.37 1687.37 1523.00T3 927.12 1633.50 1638.25 1399.63T4 779.00 1702.12 1486.87 1322.67T5 744.50 1337.00 1526.25 1202.58T6 902.00 1284.37 1511.25 1232.54T7 1406.87 1365.37 1280.50 1350.92T8 927.12 2112.50 1417.37 1485.67T9 887.12 1401.62 1456.12 1248.29

T10 1045.25 1546.50 1518.75 1370.17T11 895.25 1766.25 1451.50 1371.00T12 948.25 1513.50 1400.25 1300.67

C.D. (P=0.05) 241.09 392.955 NS NS

Rajani et al. 2010Junagadh 26

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Effect of FYM on P solubilization in calcareous soils

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• 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

28

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Table 08: Effect of combined application of phosphorus and farmyard manure application on the performance of wheat in calcareous soils

Phosphorus andFYM Levels

Plant height (cm) 1000-grainweight (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 10.74CD at 5% 0.135 0.16 0.032 0.028

Ahmad et al. 2007 FaisalabadF1=120, F2=180 and F3=240 (kg /ha)P1=60, P2=90 and P3=120 (kg P2O5/ha)

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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 % OMcontrol

0 3.87 3.39 4.9030 3.44 3.05 5.07

1.0% S0 4.97 5.26 6.2930 5.43 4.80 5.75

3% OMcontrol

0 8.99 8.00 8.9930 14.61 16.09 17.82

1.0 % S0 15.10 13.44 15.10 30 24.55 27.03 29.93

6% OMcontrol

0 18.12 16.13 18.12 30 29.46 32.43 35.92

1.0% S0 19.96 17.77 19.96 30 32.46 35.73 39.57

Al-oud S. 2011 Russia 30

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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 0.42Patel et al. (1992)Gujarat 31

TreatmentOrganic 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 0.005Udaipur RAO et al. 1997

Table 11: Effect of organic manure on P concentration at successive growth stages of groundnut (Pooled data)

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Figure 04: Effect of vermicompost on WSP content of rock phosphate during 60 days of incubation.

(V1-0%, V2-15%)

Iran Hasin et al. 200933

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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 34

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Role Of Phosphate Solubilizing Micro-organisms on Improving Phosphorus

solubilization

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Bacillus

Pseudomonos

Aspergillus awamori

PHOSPHATE SOLUBILIZING MICRO-ORGANISMS

Phosphate Solubilizing Bacteria:

Phosphate Solubilizing Fungi and phosphorus Mobilizers:

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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 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

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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 39

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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 40

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Effect of different management practices

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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

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Table 16: Effect of different methods of phosphorus fertilizer application on yield and yield components of wheat crop in calcareous

soilsTreatments Germination

(%) Plant height(cm)

Fertile tillers(m2)

Grains perspike

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 43

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Table 17:Soil phosphorus availability and uptake by groundnut under different land management options in calcareous vertisols

Treatment detailsOlsen’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. 201244

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Effect of different amendments on P uptake by crop

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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

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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 SSPP2 - 50kg P2O5/a as MRPP3 - 12.5kg P2O5 as SSP + 37.5kg P2O5 as MRPBihar Singh et al. 200047

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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. 199948Pyrite- 500kg, FYM -100q,

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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 5.32T2-RP 7.36 5.43T3-Nbiof-1 7.43 5.58T4-Nbiof-2 7.79 5.73T5-Nbiof-3 8.22 6.11T6-Biof-1 7.58 5.94T7-Biof-2 8.05 6.47T8-Biof-3 8.83 7.06T9-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.200749

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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 10.64AL-OUD. 2011 Russia 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 TotalT1- SP 21.81 14.02 35.83T2- RP 9.93 7.52 17.45T3- RP+ ES 18.74 12.29 31.02T4- RP + PSB 14.67 10.24 24.90T5- RP + OM 25.29 17 42.29T6- RP + PSB +ES 31.52 19.19 52T7- RP + ES + OM 39.48 23.07 62.55T8- RP + PSB + OM 35.38 20.79 56.17T9- RP + PSB + OM + ES 46.05 25.21 71.26

CD at 5% 1.57 1.67 2.36

Ahmed . 2013Egypt 51SP - 357kg/ha, RP-192 kg/ha, ES - 476kg/ha, OM- 6t/ha

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 DASTreatments 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

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

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Effect of other nutrients on P forms and uptake by crop

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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. 200755

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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. 200756

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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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