WEL-COME

Seminar on
NUTRIENT MANAGEMENT CHALLENGES AND OPTIONS
Presentation by
SWAMI YOGESHWAR PARMESHWAR
(REG.NO. 2017A/118M)
Research Guide Seminar In charge
Dr. S. L. WAIKAR Dr. Syed Ismail
Assistant Professor, Head,
Submitted to
DEPARTMENT OF SOIL SCIENCE AND AGRIL.CHEMISTRY
COLLEGE OF AGRICULTURE
V.N.M.K.V, PARBHANI 431402 (M.S.)
2018

Introduction
 The development of Plant Nutrient Management to increase the quantity of plant
nutrients in farming systems and thus crop productivity is a major challenge for food
security and rural development.
 The depletion of nutrient stocks in the soil is a major but often hidden form of
land degradation.
 On the other hand, excessive application of nutrients or inefficient management
means an economic loss to the farmer and can cause environmental problems,
especially if large quantities of nutrients are lost from the soil-plant system into
water or air.
 Increasing agricultural production by improving plant nutrition management,
together with a better use of other production factors is thus a complex challenge.

Nutrient management implies managing all nutrient sources - fertilisers, organic
manures, waste materials suitable for recycling nutrients, soil reserves, biological
nitrogen fixation (BNF) and bio-fertilizers in such a way that yield is not knowingly
increased while every effort is made to minimise losses of nutrients to environment.

Nutrient management:
Involves using crop nutrients as efficiently as possible to improve productivity while
protecting the environment.
The key principle behind nutrient management is balancing soil nutrient inputs with
crop requirements.
Nutrient management concepts can be distinctly defined for two broad domains:
(i) Nutrient Management Planning
(ii) Site specific nutrient management

i. Nutrient Management Planning:
 Nutrient management is: knowing what you have, knowing what you need and
managing wisely. Nutrient management plans must be site-specific.
 They are tailored to the soils, landscapes, and management of a particular farm.
In fact, nutrient management planning is much like developing a cash-flow analysis
using kilograms of N and P instead of rupees.

Steps of Nutrient Management Planning:
(i) Obtain accurate soil information for each field or management unit.
(ii) Estimate yield potential of each field
(iii) Calculate plant nutrients required to achieve the yield potential.
(iv) Determine the plant-available nutrients in manures or other organic amendments.
(v) Estimate residual nutrient contributions forms fertilizers or manures applied in previous
seasons.
(vi) Apply animal manures and/or commercial fertilizers to supply nutrients when needed by
the growing crops using best management practices.
(vii) It is clear that nutrient management planning uses the same inflow versus outflow as
cash flow analysis. Any later should be able to implement nutrient management
planning.

ii)Site specific nutrient management:
The SSNM helps in improving NUE as it provides an approach for feeding crops like
rice, maize, wheat, etc. with nutrients as and when needed.
The major benefit for farmers from improved nutrient management strategy is an
increase in the profitability.
The SSNM eliminates the wastage of fertilizers by preventing excessive rates of
fertilization and by avoiding fertilizer application when the crop does not require
nutrient inputs.
It also ensures that N, P, and K are applied in the ratio required by the intended crop.

Source: www.slidplayer/ssnm.com

Nutrient Management: Challenges
A. Declining fertilizer response and crop productivity
B. Stagnation in fertilizer production
C. Stagnating Food grain Productivity
D. Macronutrient Deficiency
E. Micronutrient Deficiency
F. Multi micro-nutrient Deficiency
G. Imbalances in Fertiliser Use
H. Gap in Nutrient supply and Nutrient Removal
I. Change in Land-Man Ratio

A. Declining fertilizer response and crop productivity:
Table.1: Declining fertilizer response ratio in India during last four decades
(Source: Rao et al.,(2015). Indian J. Fertilizes,Vol.11(4), 28-37)
Period Fertilizer Response (kg
grain per kg nutrient used)
1970-71 49.79
1980-81 24.49
1990-91 14.06
2000-01 9.98
2010-11 8.69

B. Stagnation in fertilizer production:
The country will require about 45 Mt of nutrients to produce 300 Mt of food grains for
around 1.4 billion population by 2025.
Unfortunately, the fertilizer industry is not on the desired growth trajectory for quite
sometime due to non-conducive policy environment for investments in the industry.
The country had been importing increasing quantities of fertilizers to meet the
demands, the figures being 7, 3 and 4.4 Mt of urea, phosphatic and potassic fertilizers,
respectively for 2007-08.The existing gap between demand and supply of fertilizers is
likely to grow further in the absence of any capacity enhancement. The import of
fertilizers would, obviously, cause burden on the state exchequer.
The inadequate supplies of fertilizers would lead to further mining of our soils.

C. Stagnating Food grain Productivity:
Fig.1: Productivity growth rate (% per annum) of food grain production
(Source: Rao et al.,(2015). Indian J. Fertilizers ,Vol.11(4),28-37)

D. Macronutrient Deficiency:
(Source: Rao et al., (2015 ). Indian J. Fertilizes 11(4): 28-37)
Available Nutrient Element Per cent deficiency in districts
sampled (Total 500 Districts) During
Period Of 1995-2008
Low
(283
Districts)
Medium
(182
Districts)
High
(33
Districts)
N 57% 36% 7%
P 51% 40% 9%
K 9% 42% 49%

E. Micronutrient Deficiency:
Table.2: Deficiency status of available (DTPA-extractable) micronutrients and hot water soluble B
(HWS-B) in soils of different states of India
(Source: Shukla et al.,(2015).Indian J. Fertilizers.10(12) 94-112)
State DTPA-extractable micronutrients Hot water soluble B
No. of
samples
Percent samples deficient No. of samples Percent
samples
deficientZn Fe Cu Mn
Andhra
Pradesh
6723 22.3 16.8 1.0 1.7 3216 2.8
Assam 5216 25.5 0.0 3.8 0.0 5216 11.9
Bihar 7304 41.4 12.3 1.8 7.8 3597 33.3
Gujarat 5470 23.1 23.9 0.4 6.3 5470 17.9
Haryana 5673 15.3 21.6 5.2 6.1 5673 3.3
Himachal
Pradesh
642 1.4 7.8 0.2 22.1 161 8.7
Jharkhand 443 20.3 0.0 0.5 0.0 443 56.0
Madhya
Pradesh
7580 61.7 9.6 0.2 1.6 3330 2.4
Maharashtra 8278 54.0 21.5 0.2 3.8 489 54.8
Odisha 2349 22.7 1.8 0.3 1.1 2349 52.5
Punjab 2181 16.6 6.2 3.6 15.2 1083 17.5
Tamil Nadu 31080 65.5 10.6 13.0 7.9 31080 19.9
Telangana 4799 26.9 17.0 1.4 3.8 2776 16.1
Uttar Pradesh 4788 33.1 7.6 6.3 6.5 4323 16.2
Uttarakhand 2575 9.6 1.4 1.4 4.7 2575 7.0
West Bengal 2363 11.9 0.0 1.2 0.9 1849 46.9
All India 97464 43.0 12.1 5.4 5.5 73630 18.3

Fig:2 Macro and Micronutrient deficiencies in India in the Progressive expansion in
occurrence of nutrient deficiencies:
(Source: Rattan et al. ISSS Platinum Jubilee Symposium,249-265)

F. Multi micro-nutrient Deficiency:
Table:3 Deficiency status of multi-micronutrients in soils of different states of India
(Source: Shukla et al.,(2014). Indian J. Fertilizes,10(12) 94-112)
State Two micronutrients Three micronutrients
Zn+Fe Zn+Cu Zn+Mn Zn+B Zn+Fe+Mn Zn+Cu+Mn Zn+Fe+B
Andhra Pradesh 6.40 0.40 0.61 0.81 0.16 0.03 0.16
Assam 0.00 1.50 0.00 4.47 0.00 0.00 0.00
Bihar 4.01 0.89 2.67 16.49 1.11 0.11 1.25
Gujarat 6.00 0.24 2.30 4.83 0.86 0.00 1.30
Haryana 6.38 2.22 1.80 0.74 0.85 0.37 0.46
Himachal
Pradesh
0.00 0.00 0.31 0.00 0.00 0.00 0.00
Jharkhand 0.00 0.00 0.00 11.74 0.00 0.00 0.00
Madhya Pradesh 7.56 0.12 1.35 1.50 0.59 0.01 0.24
Maharashtra 12.32 0.11 2.74 30.47 1.82 0.06 0.20
Odisha 0.34 0.17 0.26 12.22 0.04 0.00 0.17
Punjab 1.79 1.93 4.68 1.85 0.46 0.28 0.18
Tamil Nadu 8.45 10.69 6.00 13.50 1.71 2.12 1.38
Telangana 6.21 0.58 0.92 2.05 0.33 0.13 0.47
Uttar Pradesh 2.99 2.46 2.34 6.80 0.77 0.48 0.67
Uttarakhand 0.27 0.62 0.93 0.78 0.12 0.31 0.00
West Bengal 0.00 0.55 0.47 3.73 0.00 0.04 0.00
All India 6.29 3.97 3.04 8.86 1.01 0.76 0.86

G. Imbalances in Fertiliser Use:
Table.4 Consumption ratio of fertilisers in India over time
(Source: Rao et al., (2015). Indian J. Fertilizers,11(4);28-37)
Year N:P2O5:K2O
1951-52 7.9:0.9:1
19961-62 8.9:2.2:1
1971-72 6.0:1.9:1
1981-82 6.0:1.9:1
1991-92 5.9:2.4:1
2001-02 6.8:2.6:1
2007-08 5.5:2.1:1
2008-09 4.6:2.0:1
2009-10 4.3:2.0:1
2010-11 4.7:2.3:1
2011-12 6.7:3.1:1
2012-13 8.2:3.2:1

Source: Fertilizer Association Of India 2015

H. Nutrient supply and Nutrient Removal:
Fig: 3 Relationship of nutrient (N:P2O5: K2O) consumption, removal and gap
(Source:Manna et al.(2013). Indian Jourl.of soil conservation:41(2):127-135)

I. Change in Land-Man Ratio:
Table.5: Reducing land-man ratio in India over the years
(Source: Rao et al., (2015). Indian J. Fertilizers,11(4);28-37)
Year Land man ratio(Arable land and
land
under permanent crops/
Population)
1951-52 0.35
1961-62 0.32
1971-72 0.28
1981-82 0.24
1991-92 0.20
2001-02 0.16
2007-08 0.15
2010-11 0.14

The other possible causes of soil health decline are :
1. Physical degradation caused by soil erosion, compaction, crusting etc.
2. Chemical degradation caused by:
• Wide nutrient gap between nutrient renewal and supply
• High nutrient turn over in soil plant system coupled with low and imbalanced
fertiliser use
• Less use of secondary and micronutrients
• Insufficient input of organic sources because of other competitive uses
• Salinity and alkalinity in soils
3. Biological degradation due to organic matter depletion and loss of soil fauna and
flora
4. Soil pollution from industrial wastes, excessive use of pesticides and heavy
metal contamination.

Nutrient Management: Options
A. Integrated Plant Nutrient System
B. Nutrient Based Pricing And Subsidy
C. Promoting:
Fortified and Coated fertilizer
Customized and Water soluble fertilizer
Nanotechnology for slow release efficient fertilizers
D. Utilizing indigenously available nutrient sources
E. Enhancing availability of organic manure
F. Use Of Bio-fertilizers
G. Use of Vermicomposts
H. Legumes in crop rotation
I. Conservation Agriculture
J. Managing Problem Soils through Soil Amendments
K. Emerging Issues and Way Forward

A. Integrated Plant Nutrient System:
The different components of integrated nutrient management possess great diversity
in terms of chemical and physical properties and nutrient release patterns. Six basic
principles of sustainable integrated nutrient management system laid out by Dennis
Greenland (quoted by Meelu 1996) are:
i. Nutrient removed must be returned to the soil
ii. Organic carbon levels should be maintained and enhanced
iii. Soil physical conditions should be maintained and upgraded
iv. The build up of a biotic stress should be minimal
v. The soil quality with respect to soil acidity/toxic elements build up must be
sustained
vi. Degradation of land due to soil erosion must be controlled.

These principles emerge when one compares a natural ecosystem with an agricultural
ecosystem. An agricultural ecosystem differs from a natural one in that plant nutrients
are constantly being removed and in that sources of plant nutrients outside the cropped
area may be used to increase production. Three main components of an integrated
nutrient management system are (FAO- Food And Agricultural Organization, Geneva
1998):
i. Maintain or enhance soil productivity through a balanced use of mineral fertilizers
combined with organic and biological sources of plant nutrients.
ii. Improve the stock of plant nutrients in the soil.
iii. Improve the efficiency of plant nutrients, tires limiting losses to the environment.

Table. 6.Effects of tillage, water regimes and integrated N management practices on soil biological properties in wheat cultivated
under the contrasting agronomic practices.
Treatments
Soil respiration
(mg CO2 (100g)-1 soil per h-1)
Soil dehydrogenase activity
(µg TPF g-1 soil per h-1)
Microbial biomass carbon
(µg g-1soil)
Tillage (T)
Conservation tillage 36.60 2.07 163.67
Conventional tillage 20.21 1.30 80.23
C.D. (0.05) 0.85 0.09 1.69
Water management (WM)
2-irrigation (Sub-optimal) 27.32 1.50 121.82
3-irrigation (Optimum) 30.96 1.85 136.61
5-irrigation (Supra-optimum) 26.95 1.71 107.82
C.D. (0.05) 1.04 0.11 2.08
Tillage × WM (T ×WM) * * *
INM
1. Control 25.52 1.175 99.76
2. RDN through urea 30.96 1.955 115.41
3. 75% RDN through urea + 25%
RDN through farmyard manure
(FYM)
30.62 1.96 129.76
4. 75% RDN through urea + 25%
RDN through green manure (GM)
25.86 1.33 107.82
5. 75% RDN through urea +
25%through Bio fertilizer
32.22 2.10 146.49
6. 75% RDN through urea +
25%RDN through sewage sludge
25.19 1.31 108.01
7. 50% RDN as FYM + 25%RDN
through bio-fertilizer + 25% RDN
through green manure
32.72 2.144 170.95
8. Blank plot 24.21 1.191 97.32
CD (0.05)
T × INM * * *
WM × INM * * *
T ×WM × INM * * *
(Source: Sharma et al.,(2011).Brazilian Journal of Microbiology,(2);531-542)

B. Nutrient Based Pricing And Subsidy :
The subsidy on fertilizers should be fixed as per nutrient content and not product-
wise. The urea being highly subsidized allowed more use of nitrogen relative to
phosphorus and potassium - a cause of nutrient imbalance and deterioration of soil
health. To promote balanced fertilization, the Government has recently taken
historical policy decision on moving to the nutrient-based pricing and subsidy.

C. Promoting:
a. Fortified and Coated fertilizer:
The fertilizers should be fortified and coated with micro and secondary nutrients to
correct their widespread deficiencies in Indian soils.
b. Customized and Water soluble fertilizer:
A host of customized fertilizers suitable for different soil and crop situations need
to be promoted for precise nutrient applications.
c. Nanotechnology for slow release efficient fertilizer:
The nanotechnology offers immense opportunities in better nutrient management
by offering slow release fertilizers (nano porous geolites) and soil quality and plant
health monitoring systems (nano sensors). The new products and tools could
enhance nutrient use efficiency which is still low for majority of the nutrients.

D. Utilizing indigenously available nutrient sources:
We should utilize all indigenously available nutrient sources to reduce dependence on import
of fertilizer raw materials/ intermediates and finished products.
i. There are good reserves of low grade rock phosphate (160 Mt) and potassium-bearing mica in
the country
ii. The reserves uneconomic for exploitation as fertilizers, could be used for production of
enriched manures containing P and K through composting
iii. The low grade phosphate rock could also be used for direct application in acid soils.

E. Enhancing availability of organic manure:
Organic Components/
Management
Soil Properties Effects on Soil Properties
FYM,vermi-composting,
GreenManuring,
Household
waste and sewage sludge
and Soil Organic Matter
Physical
Improve soil structure, porosity, moisture retention
capacity etc. in the soil.
Chemical
Supply several macro and micro nutrients to the plants.
Increase total nitrogen, organic matter in the soil which
“is an important substrate of cationic exchange, is the
warehouse of most of the nitrogen, phosphorus, and
sulphur potentially available to plants
Biological
Soil Organic Matter is the main energy source for
microorganisms
and it increases the microbial population in the soil.
Soil micro-organisms are the living part of the soil organic
matter.
Soil organic matter has a capacity to sink the atmospheric
CO2
and thereby increase in the carbon content in the soil
which
further enhance the microbial biomass and elevate
respiration.
In general, organic fertilizer application improved nodule
dry weight
(DW), photosynthetic rates, N2 fixation, and N
accumulation as well
as N concentration in several crops.
Household waste and sewage sludge helps to have the
highest number of colony forming heterotrophic bacteria
in the soil.

Crop Rotation Physical Architectural form of different root systems of several
crops included in crop rotation and which influences the
physical structure of soil.
Chemical Crop rotations significantly increased soil pH, available
phosphate, exchangeable K and Ca in soil.
Biological Crop rotation decreases the incidence of soil-born
pathogen by increasing soil chemical properties and soil
microbial biomass.
Mulching Physical It makes the soil softer, pulverized and humid that
ultimately
helps to maintain bulk density and porosity in the soil.
It increases soil fertility, crop production and control soil
erosion; residues become decomposed and add organic
matter to the soil.
Better absorption and less run off-of water in the field.
Mulch materials improve soil physicochemical properties,
suppress soil temperature, reduce evaporation and
increase the soil
moisture.
Chemical The mulching materials become decomposed and add
organic matter and other nutrients to the soil
Biological Mulching helps to increase the population, species
diversity and
activity of macro fauna in the soil.
It improves biological activities in the soil and after
decomposition it adds nutrients to the soil.
Continued....
(Source: Biswas et al.(2014),Journal of Food, Agriculture & Environment:12:(3&4);237-243)

Figure. 4 Integration of different of organic practices for sustainability of soil health:
(Source: Biswas et al.(2014), Journal of Food, Agriculture & Environment, 12:(3&4),237-243)

F. Use Of Bio-fertilizers:
Table.7 Different groups of bio-fertilizers
(Source: Barman et al.(2017), Int.J.Curr.Microbiol.App.Sci.,6(11);1177-1186)
Sr. No. Groups Examples
1. Nitrogen (N2) fixing Bio-fertilizers
I Free-living Azotobacter, Clostridium, Anabaena, Nostoc
Ii Symbiotic Rhizobium, Frankia, Anabaena azollae
Iii Associative Symbiotic Azospirillum
2. P-Solubilising Bio-fertilizers
I Bacteria Bacillus megaterium var. phosphaticum,
Bacillus circulans, Pseudomonas striata
Ii Fungi Penicillium sp., Aspergillus awamori
3. P-Mobilizing Bio-fertilizers
I Arbuscular mycorrhiza Glomus sp., Gigaspora sp., Acaulospora sp.,
Scutellospora sp., Sclerocystis sp.
Ii Ectomycorrhiza Laccaria sp., Pisolithus sp., Boletus sp., Amanita
sp.
Iii Orchid mycorrhiza Rhizoctonia solani
4. Bio-fertilizers for Micro nutrients
I Silicate and zinc solubilises Bacillus sp, Trichoderma viride
5. Plant Growth Promoting Rhizobacteria
I Pseudomonas Pseudomonas fluorescens

Table.8 Year wise Bio-fertilizer production (in tonnes) Maharashtra:
Source: Barman et al.(2017), Int.J.Curr.Microbiol.App.Sci.,6(11);1177-1186
Year Bio fertilizer
production in tones
2008-09 1249.87
2009-10 1861.33
2010-11 2924.00
2011-12 8743.69
2012-13 5897.91
2013-14 6218.607
2014-15 14847.397

G. Use of Vermicomposts:
Table.9 Effect of Vermicomposts and NPK on the physical properties in post-harvest 75 days soil
Source: Manivannan et al.(2009), J.Environmental Biol.,30(2);275-281
Physical
Parameters
Clay loam soil Sandy loam soil
T1 T2 T3 T4 CD
Value
T1 T2 T3 T4 CD
Value
Pore
space%
35.41 34.27 38.87 36.87 5.87 ⃰ 32.51 32.17 33.21 32.28 5.01 ⃰
Particle
Density
(Mgm-3)
1.69 1.62 1.39 1.44 1.12 ⃰ 1.68 1.61 1.43 1.56 1.02 ⃰
Bulk
density
(Mgm-3)
1.13 1.17 0.98 1.09 0.14 ⃰ 1.24 1.26 1.01 1.08 0.18 ⃰
WHC(%) 83.80 81.60 94.80 92.30 0.68 ⃰ 59.20 56.40 75.50 67.20 0.65 ⃰
CEC(coml.
(p+)kg-1)
24.30 24.00 28.70 26.90 0.26 ⃰ 23.20 23.00 28.10 26.3 0.23 ⃰
T1 = Control (without application of inorganic fertilizer or manure), T2 = Recommended dose of NPK (20:80:40
kg ha-1), T3 = Recommended dose of Vermicomposts (5tonnes ha-1), T4 = Application of 50% Vermicomposts +
50% NPK, WHC =Water holding capacity, CEC= Cation exchange capacity

Table.10 Effect of Vermicomposts and NPK on the chemical properties in post-harvest 75 days soil:
Source: Manivannan et al.(2009) J. Environ.Biol.,30(2);275-281
Chemical
Parameters
Clay loam soil Sandy loam soil
T1 T2 T3 T4 CD
values
T1 T2 T3 T4 CD
Values
pH 7.15 7.19 7.08 7.11 0.02NS 7.14 7.18 6.97 7.09 0.03NS
EC(dsm-1) 0.87 0.93 0.61 0.71 0.04 ⃰ 0.58 0.50 0.49 0.52 0.02NS
OC(%) 0.23 0.22 8.52 3.71 0.12 2.00 0.21 9.42 5.06 1.18 ⃰
Available nutrients
N(kg ha-1) 125 190 207 201 0.82 117 188 200 193 1.92 ⃰
P(kg ha-1) 11.21 13.1 16.8 15.3 0.31 8.5 9.0 14.1 12.2 0.38 ⃰
K(kg ha-1) 206 240 317 267 3.11 203 235 290 260 4.12 ⃰
Total nutrient
Ca(%) 1.70 1.74 3.07 2.69 0.18 1.59 1.63 2.97 2.08 0.12 ⃰
Mg(%) 0.56 0.53 0.87 0.63 0.03NS 0.38 0.37 0.59 0.50 0.02NS
Na(%) 0.07 0.06 0.17 0.11 0.02NS 0.04 0.05 0.15 0.09 0.03NS
Fe(pap) 11.70 11.48 82.12 50.11 0.31 10.30 10.67 78.69 41.78 0.28*
Mn(ppm) 11.9 11.4 97.6 86.7 2.12 9.5 9.1 96.5 79.5 2.61*
Zn(ppm) 1.17 1.13 58.6 39.4 0.25 1.10 10.09 57.5 39.8 0.38*
Cu(ppm) 1.50 1.61 20.8 15.6 0.28 0.94 0.97 20.6 15.2 0.33*
T1 = Control (without application of inorganic fertilizer or manure), T2 = Recommended dose of NPK (20:80:40 kg
ha-1),
T3 = Recommended dose of Vermicomposts (5 tones ha-1), T4 = Application of 50% Vermicomposts + 50% NPK

Table.11 Effect of Vermicomposts and NPK on the biological properties in post-harvest 75 days soil:
Source: Manivannan et al.(2009) J. Environ.Biol.,30(2);275-281
Biological
Parameters
Clay loam soil Sandy loam soil
T1 T2 T3 T4 CD
values
T1 T2 T3 T4 CD
Values
Bacteria
(CFU×106g-1)
42.6 40.1 50.4 54.1 1.08* 32.1 29.1 36.2 33.1 1.03*
Fungi
(CFU×104g-1)
40.1 32.1 42.1 41.0 0.49* 28.7 26.5 35.1 30.2 0.45*
Actinomycetes
(CFU×105g-1)
8.5 7.1 10.7 9.5 0.19* 6.3 6.0 7.5 6.9 0.15*
Total Micro-
bial population
(CFU×106g-1)
43.8 41.1 51.8 46.5 2.12* 33.0 29.9 37.2 34.1 2.38
Microbial
activity(5mlH/
5g)
4.1 4.0 5.9 4.8 0.13* 3.1 3.0 4.6 4.1 0.09*
T1 = Control (without application of inorganic fertilizer or manure), T2 = Recommended dose of NPK
(20:80:40 kg ha-1),
T3 = Recommended dose of Vermicomposts (5 tones ha-1), T4 = Application of 50% Vermicomposts + 50%
NPK

H. Legumes in crop rotation:
Table.12 Biological Nitrogen Fixation (BNF) estimates for India
Source: Das et al.(2012) Outlook on Agriculture.,41;(4)
Crop Area (m ha) N fixed (kg/ha) Annual fixation
(million tonnes)
Chickpea 6.09 40 0.24
Pigeon pea 3.38 100 0.34
Mung bean 0.09 60 0.19
Urdbean 3.25 30 0.10
Cow bean 0.50 80 0.002
Field pea 0.81 65 0.005
Lentil 1.39 40 0.006
Groundnut 6.40 150 0.96
Soybean 6.22 100 0.61
Total 34.28 - 2.47

Table.13 Root exudates and P- fraction dissolved:
Source: Das et al.(2012) Outlook on Agriculture.,41;(4)
Crop Acid exuded P fraction dissolved
Chickpea Citric acid Calcium P
Pigeon pea Piscidic acid Ferric P
Lupinus albus Citric acid Ferric P
Alfalfa 2-(3 S dihydroxy
phenyl)- 5,6-
di-hydrobenzofuran
Ferric P
Soybean Citric acid, malonic
acid
Calcium P

I. Conservation Agriculture:
II. Table: 15 Some distinguishing features of conventional and conservation agriculture systems:
Source:Baban et al.(2014) Inter.Journal on Soil and water conservation research.,2:(4);1-12
Conventional agriculture Conservation agriculture
Cultivating land, using science and technology to dominate
nature
Least interference with natural processes
Excessive mechanical tillage and soil erosion No-till or drastically reduced tillage
(biological tillage)
High wind and soil erosion Low wind and soil erosion
Residue burning or removal (bare surface) Surface retention of residues
(permanently covered)
Water infiltration is low Infiltration rate of water is high
Use of ex-situ FYM/composts Use of in-situ organics/composts
Green manuring (incorporated) Brown manuring/cover
crops (surface retention)
Kills established weeds but also stimulates
more weed seeds to germinate
Weeds are a problem in the early stages of adoption but
decrease with time
Free-wheeling of farm machinery, increased soil compaction Controlled traffic, compaction in tramline, no
compaction in crop area
Mono cropping/culture, less efficient rotations Diversified and more efficient rotations
Heavy reliance on manual labour, uncertainty of operations Mechanized operations, ensure timeliness of operations
Poor adaptation to stresses, yield losses
greater under stress conditions
More resilience to stresses, yield losses are less under
stress conditions
Productivity gains in long-run are in
declining order
Productivity gains in long-run are in
incremental order

Conclusion:
Magnitude of Zn, B, Fe deficiencies in Indian soils is 49, 33 & 13% respectively, which is
most critical to sustain soil health for micronutrients.
The availability of ‘N’, P’ and ‘K’ restricted by ‘N’ loss by leaching and volatization,'P ' by
fixation and ‘K’ by immobilization.
Bio-fortification and use of Bio-fertilizers will help to improve both nano and micro-nutrients
in soil.
Bio-fertilizers have potential role in sustainable agriculture these can be used along with
chemical fertilizers to enhance the soil fertility and crop yield.

Amelioration of problems soils and use of poor quality water in agriculture is very essential for
accelerating the crop productivity with proper amendments for enhancing the soil health.
Efficient recycling of nutrients from available organic residues, manures and composts can
assist in narrowing the gap between nutrient removals by crops and insufficient nutrient
replenishment.
In crop production, all possible resource conservation measures need to be adopted depending
on the availability of water, nutrients and agro-climatic limitations, including the concept of
conservation agriculture.