Phosphorus is an essential primary nutrient for plant growth and is a critical component of fertilizers. However, it is a finite resource, and concerns have been raised about the depletion of high-quality phosphate rock reserves, which are the primary source of phosphorus for fertilizer production. Phosphorus is an exception, as it exists as an anion but has low water solubility, making it relatively immobile in the soil (Roberts and Johnston, 2015). Phosphorus use efficiency can vary depending on factors like soil conditions, crop varieties, and agricultural practices. Fixation of broadcasted P is much greater than the fertilizer applied in bands because of less contact with P fixing ingredients (Rehim et al., 2012). The PUE is very low in alkaline soil due to fixation with calcium or magnesium ions which reduces the P availability to the plants. Coating of phosphorus fertilizers with organic acids can improve the PUE without harming the environment (Mohan and Malarvizhi, 2020). Biochar application improves crop productivity through enhancing water holding capacity, cation exchange capacity (CEC), adsorption of plant nutrients and creates suitable condition for soil micro-organisms (Atkinson et al., 2010). Rock phosphate if used as nano form it may increase availability of phosphorus to the plant because direct application of rock phosphate nano particles on the crop may prevent fixation in the soil similarly there is no silicic acid, iron and calcium for fixation of the phosphorus hence it increase phosphorus availability to the crop plants (Qureshi et al., 2018). Microbial Inoculants in the rhizosphere have been known as System of INM. The fixed or relatively unavailable fraction of P may be distributed to proportionally more labile fractions, which can be taken up by the plants, as a result of PSM (Phosphorus Solubilizing Microbes) application. In case of Ultisols of India, there is very little information on the pattern of P release into soil solution due to microbial solubilization of fixed soil P (Alam et al., 2021). Product coated with polyvinyl alcohol @2% coating released P gradually that synchronized well with the plant P demand and resulted in greater biomass yield, P uptake and recovery by wheat than that of liquid paraffin and 3% level of coating. It can be concluded that novel technology of controlled release RP formulations using different coating agents could be exploited commercially as the alternative to water soluble P-fertilizers for enhancing P use efficiency (Sarkar et al., 2018). Polymer coating has been found more effective than other fertilizer encapsulation technologies. In case of polymer coated fertilizers (PCFs), the shelf life and efficiency of nutrients is higher. Keeping this in view polymer coated DAP was formulated, and a field study was conducted with aims to compare the effectiveness of polymer coated DAP and commercial DAP for improving growth, yield and PUE of wheat (Ali et al., 2017)

1. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
WELCOME

2. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Phosphorus use efficiency (PUE); Present scenario
Phosphorus use efficiency: 15-20% ( In general) Crop Group PUE
Cereals 20 – 30 %
Legumes 35 – 50 %
Oil seeds 30 – 45%
Soil Type PUE
Acidic Soil 10 – 20 %
Calcareous soil 15 – 20%
Alkaline soil 15 – 25%
Saline soil < 10 %
Hopkins et al., 2014
Phosphorus use
efficiency of different
crop groups
PUE on different soil types
Deshbhratar et al., 2010

3. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Presented by - S G Sarowar
Contact No- +91 6295726146
Email id- sarowar13998@gmail.com
Division of Soil Science and Agricultural Chemistry
ICAR - Indian Agricultural Research Institute, New Delhi

4. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Outlines
 Introduction
 Phosphorus use efficiency - overview
 Innovative approaches for enhancing PUE
 Application of amendments; lime & biochar
 Agronomic management: legume intercropping
 P Solubilizing microbes – Azotobacter sp. &
Arbuscular micorrhizae
 Soil phosphorus bioavalability; rhizosphere processes
 Organic acid coated DAP
 Role of Biofertilizer for enhancing PUE
 Novel fertilizer; (New sources)
 Nano clay polymer coated DAP (IFFCO and
Coromandel)
 Root-activated P fertilizer (Taurus group)
 P-rich composts (PROM)
 Conclusions
 Path ahead

5. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Introduction
• Phosphorus is 11th most abundant element on earth crust &
second most limiting nutrient after N in most of the soils.
• Phosphorus is involved in photosynthesis, cell division, tissue
development, growth & genetic transfer etc in plant.
• About 43% of world’s arable soil is P deficient.
Available phosphorus range in soil
Content Value (ppm)
Very low 0- 5
Low 6-12
Medium 13-25
High 26-50
Exessive >50
Habumugisha et al., 2019

6. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Three major aspects of PUE
Syers et al., 2008
Phosphorus Uptake
Efficiency
Phosphorus Utilization
Efficiency
Phosphorus Recovery
Efficiency
The ability of plants to take up
phosphorus from the soil
The efficiency with which plants use
absorbed phosphorus for growth and
development.
The ratio of phosphorus recovered
by plants to the total phosphorus
applied as fertilizer.

7. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Different types of Phosphorus Use Efficiency
Continued long-term application of P fertilizers and organic wastes and
manures can lead to accumulation of P in surface horizons due to the low
crop use efficiency (<25%) in the year of application.
Yadav et al., 2021

8. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Time and method of application of conventional P fertilizers
Bindraban et al., 2020

9. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Manufacturing process and method of P fertilizer application
Phosphorus release pattern from
novel synthesized coated
controlled release rock
phosphate formulations and
commercial DAP during soil
incubation period.
Idealised crop response to
phosphorus as affected by
fertilizer placement
Sarkar et al., 2018
Breker, 2022
For wheat and maize, band
placement of P (especially
deep) often led to higher yields
and is therefore recommended

10. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
How Phosphorus works on soil?
Jeschke et al., 2017

11. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Innovative approaches for enhancing PUE
PUE
P
Solubilizing
microbes
Inter
cropping
with
legumes
Organic
&
Inorganic
acids
ligands
Lime &
Biochar
addition
Novel
Fertilizer
P efficient
crops by
breeding
Time and method
of application of
conventional P
fertilizers
Source of P: Novel
fertilizers, e.g.,
Nano clay polymer
coated DAP
(IFFCO and
Coromandel), Root-
activated P
fertilizer (Taurus
group), P-rich
organic manure
(PROM)
Soil phosphorus
bioavailability –
Rhizosphere
process

12. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Application of amendments: Biochar
Ghodszad et al., 2021

13. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Effect of application of amendments; Lime and Biochar on
available phosphorus
Effect of biochar and lime on available phosphorus
Abewa et al., 2013
2 t/ha lime ~ 8 t/ha biochar < 12 t/ha biochar
12 biochar No amendment

14. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Effect of biochar on CEC & exchangeable acidity
CEC;
influenced
by biochar
and lime
application
Effect of biochar on
exchangeable acidity
Abewa et al., 2013

15. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Agronomic management: legume intercropping
Jha et al., 2023

16. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Relationship between P uptake and yield of cereals and legumes in
intercrops and sole crops
Relationship between P uptake and yield of cereals and legumes in intercrops and pure
stands shows no differences in yield between intercrops and sole crops
Closed symbols - observations in sole crops
Open symbols - observations in intercrops
Red - cereals
Blue- legumes
Tang et al., 2020

17. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
P Solubilizing microbes – Bacteria (Azotobacter sp.)
Zaidi et al., 2009
P

18. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Total Phosphorus release crossponding with phosphorus
solubilizer and therir incubation time
Release pattern of
phosphorus (mg/kg) in soil as
mediated by phosphate
solubilizing microorganisms.
Population of phosphate
solubilizing microorganisms
(cfu/g dry soil) in inoculated
soil during incubation
Period & Total phosphorus
release.
Alam et al., 2020
PSB, PSF (Phosphate
solubilizing Bacteria,
fungi)
Soil Type – Highly
weathered ultisol

19. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Soil phosphorus bioavailability – Rhizosphere processes
Rhizosphere processes involved in soil phosphorus bioavailability and plant
uptake - diffusion through soil solution; sorption desorption balance -
organic phosphorus (Po) mineralization; and fixation in microbial biomass.
Blackburn et al., 2007
Microbial inoculants in
the rhizosphere have
been known as systems
of integrated nutrient
management, with a
specific interest in their
ability to enhance the
availability of P for
crops.

20. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Effect of organic acid coated DAP for enhancing agronomic PUE
Response of organic acid-
coated DAP on PUE
9. NK+P as
HA coated
DAP (20%)
Soil Type - Sandy loam
Crop - Brinjal
Mohan et al., 2020
No. Treatments PUE*
1 N K + P as uncoated DAP 24.92
2 N K + P as FA coated DAP (5%) 28.92
3 N K + P as FA coated DAP (10%) 27.57
4 N K + P as FA coated DAP (15%) 29.23
5 N K + P as FA coated DAP (20%) 31.73
6 N K + P as HA coated DAP (5%) 23.69
7 N K + P as HA coated DAP (10%) 31.73
8 N K + P as HA coated DAP (15%) 33.82
9 N K + P as HA coated DAP (20%) 35.85
10 Control -
*Agronomic PUE (q/Kg of phosphorus applied)

21. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Role of Biofertilizer for enhancing PUE
Soil physicochemical and biochemical as well as
microbial properties PUE
Chatterjee, 2017

22. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Effect of biofertilizer on phosphorus utilization efficiency
Inoculation effect on phosphorus utilization efficiency (PUtE) of two-rowed barley
crop. AMF inoculation treatments: With and without AMF inoculation,
respectively in alluvial soil.
Effect of Arbuscular Mycorrhizal
Fungi Phosphorus Uptake
Efficiency and Crop Productivity
of Two-Rowed Barley System
Blue line - With
Arbuscular Mycorrhizal
Fungi (AMF)
Green line – Without
Arbuscular Mycorrhizal
Fungi (AMF)
Beslemes et al., 2023

23. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi New Sources of Posphorus & their effect for enhancing PUE
Novel fertilizers:
 Nano clay polymer coated
DAP (IFFCO and
Coromandel)
 P-rich composts (PROM)
 Root-activated P fertilizer
(Taurus group),

24. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Novel Fertilizer – Mechanism for enhancing PUE
Sarkar et al., 2018

25. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Effect of Nano clay polymer coated DAP on P concentration
Effect of Nano clay polymer coated DAP on P concentration of wheat
a - straw
b - grain
Species - Triticum aestivum
Soil Type – Alfisol
Source – IFFCO, Coromandel
Ali et al., 2017

26. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Effect of phosphorus rich organic matter (PROM) on phosphorus
concentration (ppm) in soil
Noor et al., 2021
Soil Type - New alluvial soil of South-West Bengal

27. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi Root-activated P fertilizer – Comparision between crystal green
and MAP (Mono ammonium phosphate) by corresponding
Proven root-activated P fertilizer release, reduces
fixantion and impact of runoff; 94% remains plant
available after fall fertilization.
Taurus, 2023
Soil type – Neutral to slightly alkaline soil

28. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Conclusions
 Product from rock phosphate coated with polyvinyl alcohol @
2%coating released P gradually that synchronized well with the
plant P demand and resulted in greater biomass yield, P uptake
and recovery by wheat than that of liquid paraffin and 3% level
of coating.
 Biochar application improves crop productivity through
enhancing water holding capacity, cation exchange capacity
(CEC), adsorption of phosphorus and creates suitable condition
for soil micro-organisms.
 The use of beneficial microorganisms, nano fertilizer, breeding
techniques, intercropping with legumes increases crop yield
efficiently for meeting the growing global demand for food.

29. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Path ahead
 Government subsidies, financial incentives, or grants
can help offset the initial costs of adopting innovative
phosphorus use efficient technologies or practices.
Additionally, research and extension services can
provide information on cost-effective approaches and
their long-term benefits.
 Offer training and technical support to farmers to help
them understand and implement these approaches
effectively.
 Conduct proper statistcal designs, specially in case of
P Solubilizing microbes that account for regional and
local variations in soil types, climate conditions and
crop varieties.

30. Soil
Science
and
Agricultural
Chemistry,
ICAR-IARI,
New
Delhi
Thank You
My presentation is now ready for discussion…