FERTILIZER RECOMMENDATION –
HISTORICAL PERSPECTIVE
By
DR. SHAHID MAHMOOD
SOIL FERTILITY
 The ability of a soil to support
satisfactory plant growth
 Ensures nutrient and water supplies
 Provides cosy conditions for root growth,
development and harvesting of potential yield
Soil Fertility
• Reasons of low
soil fertility
–
–
–
–
–
Inherent
Leaching
Erosion
Fixation
Removal
• How to access
–
–
–
–
Soil Testing
Tissue Analysis
Fertilizer Trials
Deficiency Symptoms
Soil Quality
•
Soil quality is the capacity of soils within
landscapes to sustain biological productivity,
maintain environmental quality, and promote
plant and animal health.
•
Protecting soil quality like protecting air
quality and water quality should be
fundamental goal of our Nation’s
Environmental Policy
Poor
Good
Nutrient Composition of a
Fertile Soil
 Organic Matter
 Extractable P
 Extractable K
>
>
>
1.3 %
21 ppm
180 ppm
 DTPA
 DTPA
 DTPA
 DTPA
 0.1N
>
>
>
>
>
1.0
0.2
4.5
1.0
0.5
Zn
Cu
Fe
Mn
HCl
ppm
ppm
ppm
ppm
ppm
INHERITED LOW SOIL FERTILITY
Causes
•
•
•
•
•
Parent material (Alluvial)
Arid / harsh climate
Low Organic Matter (OM)
High pH
Calcareousness
Nutrients removal per
tonne of wheat
Usage 04
39
40
30
62
60
60
Kg / acre
10
20
70
0.3
10
0
50
40
33
30
29
25
24
20
20
10
30
9
11
14
9
0
Wheat
Rice
Cotton
S. Cane
N
P
K
Fertilizer Consumption Pattern
% Product Share 08 - 09
% Fertilizer Consumption
Others
Rice
% Area
Sugarcane
Wheat
Cotton
Major Cause of Low Production: Nutrient Deficiency
Photosynthesis: CO2 + H2O  carbohydrates (CHO) + O2
•Besides NPK, other
nutrients such as Zinc,
Iron, Boron etc. though
required in small
quantities, but their
deficiency significantly
impacts plant growth &
life.
Nutrients are taken up primarily by the roots
in the form of an aqueous solution in the soil
• Micronutrient deficiency
(Zinc, Boron, Iron &
Mangnese) in Pakistani
soils is increasing
Innumerable experiments on farmers fields prove that there is significant
increase in Yields by application of micronutrients along with NPK
Effect of Urea and P fertilizers on
wheat production in Pakistan
25
4.1
- Wheat Production
- Sales (DAP+NP+TSP)
-- Sales (Urea)
3.9
3.9
23.3
3.1
21
19
2.6
2.7
3.4
21.3
2.8
19.2
19.0
21.6
3.3
21.0
2.9
3.0
19.5
2.4
18.2
1.9
17
1.4
1.18
15
0.81
0.76
00 - 01
01 - 02
0.85
0.90
1.02
0.93
0.79
13
0.9
0.4
02 - 03
03 - 04
04 - 05
05 - 06
06 - 07
07 - 08
Fertilizer Off Take (million ton)
Wheat Production (million tons)
23
Genetically Modified Crops
2004
100
2006
87
80
2008
2012
2015
Sources
• Agri Ext data for Punjab
• Multinational Companies
% of Cropped Area
80
60
50
49
38
40
30
25
20
38
19 20
27
25
30
35
40
10
0 2
0
0
Cotton
•
•
•
Rice
Maize
Sunflower
Area under GMO crops is increasing at higher pace
GMOs consume 50 – 100% more fertilizers than normal varieties of same crop
Higher net return Vs normal verities encourage farmers for higher per acre investment
46
BALANCED FERTILIZTION----A KEY
STRATEGY TO ADDRESS THE ISSUE
•
•
•
Use of Balanced Fertilizers,
Organic fertilizers and Biofertilizers can provide viable
leverage to increase crop
productivity
It enrich the soil with important
nutrients
Bio-fertilizers has potential to
generate additional income to
farmers from the same size of
land
•
•
•
•
•
Improving soil fertility through
IPNM
Improve soil physical conditions by
increasing SOM
Inclusion of leguminous crops in
cropping systems
Proper time and method of
fertilizer application
Narrow down the N:P ratio (1:1 or
3:2)
Response Curve Studies
NPK
No Fertilizer
METHODOLOGY
• Variable treatments
• Different cropping systems
• Long term experiments
• Soil property parameters
• Farmers field
Marginal return (MR) &
Marginal rate of return (MRR)
1. Marginal return (MR)
The yield increase produced by an additional fertilizer
unit is called the marginal return of unit.
2. Marginal rate of return (MRR)
It is the ration between return on the investment
obtained from each additional fertilizer unit over the
investment itself.
MRR = Value of add. Crop – value of add. Fertilizer
Value of additional fertilizer
It can be positive or negative. Thus at
MRR = 1, Economic optimum rate
MRR = 0, Maximum profit
MRR = 1, Maximum yield
Economic of Fertilizer Use
Among different yield controlling factors fertilizers contributing is
more than 50 %. Factors contribute for decision making.
The highest profit is usually the main motivation for
fertilizer use. The main factors that impact the fertilizer
use by the farmers are:
1.
2.
3.
The price relationship between fertilizer and crop
commodity.
Response of crop to fertilizer application.
Economic returns on investment.
The question is to how much fertilizer to apply to a
specific crop in order to maximize profit. Before
answering the question I would like to explain the
following indicators that are used in the economic
analysis.
FERTILIZER RESPONSE CURVE STUDIES ON WHEAT
IN IRRIGATED AREAS
Objectives:
Location:
Formulation of fertilizer recommendations
Irrigated area of Punjab province
TREATMENTS
N
P
K
Kg/ha
0
0
0
0
114
60
80
114
60
160
114
60
240
114
60
160
0
60
160
57
60
160
171
60
160
114
0
160
114
30
160
114
90
Response Curve Studies on Wheat
(IRRIGATED)
Wheat Response Curves (Rice Zone)
OPTIMUM LEVELS
SOIL TEST
• OM %
0.78 +/- 0.17
• P mg/kg 5.8 +/- 3.6
• K2O mg/kg 131 +/- 35
………………………….
5000
Grain Yield kg/ha
• N
140 kg/ha
• P2O5 77 kg/ha
• K2O
----
P
4500
K
4000
N N
R2 = 0.9928
P
R2 = 0.9966
K
R2 = 0.8844
3500
3000
2500
0
50
100
150
200
Nutrient kg/ha
250
300
From this graph it appears that increasing the
fertilizer level gradually led to the following:
• Diminishing increase in the yield (decreasing
marginal per fertilizer unit)
• Gradually decreases in the MRR and the
VCR
• Maximum net profit per ha will be at the point
where MRR = 0
No. of Field Trials Conducted up to 2010 – 11
Crops
No. of Trials
Grain crops
42950
Cash crops
10077
Fodders
1189
Oilseeds
1650
Vegetables, Fruits, Pulses and others
2823
Total
58689
Economic of Fertilizer Use
The highest profit is usually the main motivation for
fertilizer use. The main factors that impact the
fertilizer use by the farmers are:
1. The price relationship between fertilizer and crop
commodity.
2. Response of crop to fertilizer application.
3. Economic returns on investment.
The question is to how much fertilizer to apply to a
crop in order to maximize profit. Before answering
the question I would like to explain the following
indicators that are used in the economic analysis.
Impact of balanced fertilization on Wheat
Impacts
Particulars
Balanced fertilization (BF)
Yield = 3926 kg/ha
Farmers’ practices
Yield = 2905 kg/ha
Increased yield due to BF
Yield = 1.021 ton/ha
% increase in yield due to BF
= 35 %
Gross return
= 101278 Rs. in million
Additional expenditure for BF
= 7172 Rs./ha
Net return
= 55747 Rs. in million
Impact of balanced fertilization on
Fine Rice
Impacts
Particulars
Balanced fertilization (BF)
Yield = 5472 kg/ha
Farmers’ practices
Yield = 4583 kg/ha
Increased yield due to BF
Yield = 0.889 tons/ha
% increase in yield due to BF
= 19.4 %
Gross return
= 32594 Rs. in million
Additional expenditure for BF
= 8463 Rs./ha
Net return
= 20183 Rs. in million
Impact of balanced fertilization on Maize
Impacts
Particulars
Balanced fertilization (BF)
Yield = 4352 kg/ha
Farmers’ practices
Yield = 3056 kg/ha
Increased yield due to BF
Yield = 1296 kg/ha
% increase in yield due to BF
= 42.4%
Gross return
= 11081 Rs. in million
Additional expenditure for BF
= 6313 Rs./ha
Net return
= 8082 Rs. in million
Impact of balanced fertilization on
Cotton
Impacts
Particulars
Balanced fertilization (BF)
Yield = 3167 kg/ha
Farmers’ practices
Yield = 2372 kg/ha
Increased yield due to BF
Yield = 795 kg/ha
% increase in yield due to BF
= 33.52 %
Gross return
= 50051.4 Rs. in million
Additional expenditure for BF
= 7610 Rs./ha
Net return
= 30887.1 Rs. in million
Impact of balanced fertilization on
Sugarcane
Impacts
Particulars
Balanced fertilization (BF)
Yield = 89.64 ton /ha
Farmers’ practices
Yield = 82.97 ton /ha
Increased yield due to BF
Yield = 6.67 ton /ha
% increase in yield due to BF
=8%
Gross return
= 5267.7 Rs. in million
Additional expenditure for BF
= 6125 Rs./ha
Net return
= 1318.9 Rs. in million
Number of fruits (>35%) were counted in
Zn50-B25 compared to control.
500
Fruits no./plant
a
b
400
300
b
b
b
c
200
100
0
B0Zn0
B25Zn0 B50Zn0 B0Zn50 B0Zn100 B25Zn50
Treatments
Harvested fruits were higher (19%) in Zn50-B25
compared to control.
20
ab
ab
B25Zn0
B50Zn0
ab
a
b
100 fruit wt. (kg)
c
15
10
5
0
B0Zn0
B0Zn50 B0Zn100 B25Zn50
Treatments
Fertilizer Use Efficiency:
An Old Topic but With Great Importance
As food demands to increase per acre yield to feed surging population.
Fundamentals of natural systems ….indicate a major and expanding role of fertilizers in food
production
– Issue: to optimize N and P beneficial role in sustainable crop production and minimize N’s
negative effects in the environment resulting from crop production.
– Issue: focus attention on improving fertilizer N and P efficiency
– Issue: Poor efficiency in plant uptake of nutrients applied.
Increasing Nutrient Use Efficiency
–
–
–
–
–
–
Synchrony of Nutrient Supply with Crop Nutrient Demand
Balanced Fertilization
Integrated Crop Management
Nutrient Efficient Genotypes
Improve farming practices that improve nutrient use efficiency
Need extension of collective understanding about nutrient use
efficiency for N and P
Areas of opportunity for improvement in
fertilizer use efficiency
• Continued improvement in cropping system
management
– Optimizing production
– Yield potential protection – pest management and
other cultural practices
– Use of site-specific fertilizer application
– Understanding of soil N mineralization, P & K fixation
– Best time of fertilizer application
– Use of organic sources
– Improving quality (nutrition)
– Biotechnology?
Site Specific Nutrients Management:
STRATEGIES
•
•
•
•
•
•
•
•
Improvement in soil, water , fertilizer testing facilities
Nutrient dynamics and indexation in cropping
systems for precise diagnosis of the nature, extent
and severity of Macro + Micro nutrient disorders
Long term micronutrient balance sheet studies in
major cropping sequences to permit efficient
management and provide negative impact on
environment
Nutritional requirements of horticultural and high
value crops
Sustaining agricultural systems through IPNS
Development of critical limits for different cropping
systems in different agro-eco-zones
Plant nutrition management on problem soils
Policy makers should devise long term strategy to address
fertilizer shortage particularly at the time of sowing