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FERTILIZER RECOMMENDATION – HISTORICAL PERSPECTIVE
By
DR. SHAHID MAHMOOD
The ability of a soil to support The ability of a soil to support satisfactory plant growthsatisfactory plant growth
Ensures nutrient and water suppliesEnsures nutrient and water supplies
Provides cosy conditions for root growth, Provides cosy conditions for root growth, development and development and harvesting of potential yieldharvesting of potential yield
SOIL FERTILITY
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 PolicyPoor Good
Organic MatterOrganic Matter >> 1.3 %1.3 % Extractable PExtractable P >> 21 ppm21 ppm Extractable KExtractable K >> 180 ppm180 ppm
DTPADTPA ZnZn >> 1.0 ppm1.0 ppm DTPADTPA CuCu >> 0.2 ppm0.2 ppm DTPADTPA FeFe >> 4.5 ppm4.5 ppm DTPADTPA MnMn >> 1.0 ppm1.0 ppm 0.1N 0.1N HClHCl >> 0.5 ppm0.5 ppm
Nutrient Composition of a Fertile Soil
INHERITED LOW SOIL FERTILITY
• Parent material (Alluvial)
• Arid / harsh climate
• Low Organic Matter (OM)
• High pH
• Calcareousness
Causes
Nutrients removal per Nutrients removal per tonne of wheat tonne of wheat
25
9
33
20
11
30
62
14
60
24
9
29
0
10
20
30
40
50
60
70
Wheat Rice Cotton S. Cane
N
P
KKg
/ a
cre
Kg
/ a
cre
0
10
20
30
403939
1010
0.30.3
Usage 04
Fertilizer Consumption Pattern
Wheat
Cotton
Sugarcane
Rice
Others
% Fertilizer Consumption
% Area
% Product Share 08 - 09
Major Cause of Low Production: Nutrient Deficiency
Nutrients are taken up primarily by the roots in the form of an aqueous solution in the soil
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.
• 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
19.018.2
19.219.5
21.6 21.3
23.3
21.0
0.81 0.76 0.85 0.901.02 0.93
1.18
0.79
2.6 2.72.8
3.1
4.1
3.03.3
3.9
0.4
0.9
1.4
1.9
2.4
2.9
3.4
3.9
13
15
17
19
21
23
25
00 - 01 01 - 02 02 - 03 03 - 04 04 - 05 05 - 06 06 - 07 07 - 08
Fer
tili
zer
Off
Tak
e (m
illi
on to
n)
Whe
at P
rodu
ctio
n (m
illi
on to
ns)
- Wheat Production- Sales (DAP+NP+TSP)-- Sales (Urea)
Genetically Modified Crops
0 0
1925
210
20
303025 27
35
80
38 38 40
87
49 5046
0
20
40
60
80
100
Cotton Rice Maize Sunflower
2004 2006 2008 2012 2015
• 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
% o
f C
rop
ped
Are
a
Sources•Agri Ext data for Punjab•Multinational Companies
BALANCED FERTILIZTION----A KEY STRATEGY TO ADDRESS THE ISSUE
• Use of Balanced Fertilizers,
Organic fertilizers and Bio-
fertilizers 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. FertilizerValue of additional fertilizer
It can be positive or negative. Thus atMRR = 1, Economic optimum rateMRR = 0, Maximum profitMRR = 1, Maximum yield
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 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.
Among different yield controlling factors fertilizers contributing is more than 50 %. Factors contribute for decision making.
FERTILIZER RESPONSE CURVE STUDIES ON WHEAT IN IRRIGATED AREAS
Objectives: Formulation of fertilizer recommendationsLocation: 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)
OPTIMUM LEVELS
• N 140 kg/ha• P2O5 77 kg/ha• K2O ----
SOIL TEST
• OM % 0.78 +/- 0.17
• P mg/kg 5.8 +/- 3.6• K2O mg/kg 131 +/- 35………………………….
KN
P
Wheat Response Curves (Rice Zone)
R2 = 0.9928
R2 = 0.9966
R2 = 0.88442500
3000
3500
4000
4500
5000
0 50 100 150 200 250 300
Nutrient kg/ha
Gra
in Y
ield
kg
/ha
N
P
K
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
Crops No. of Trials
Grain crops 42950
Cash crops 10077
Fodders 1189
Oilseeds 1650
Vegetables, Fruits, Pulses and others 2823
Total
58689
No. of Field Trials Conducted up to 2010 – 11 No. of Field Trials Conducted up to 2010 – 11
Economic of Fertilizer UseThe 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.
Particulars Impacts
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 Wheat
Particulars Impacts
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 Fine Rice
Particulars Impacts
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 Maize
Particulars Impacts
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 Cotton
Particulars Impacts
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
Impact of balanced fertilization on Sugarcane
Treatments
B0Zn0 B25Zn0 B50Zn0 B0Zn50 B0Zn100 B25Zn50
Fru
its
no
./p
lan
t
0
100
200
300
400
500a
bbbb
c
Number of fruits (>35%) were counted in Zn50-B25 compared to control.
Treatments
B0Zn0 B25Zn0 B50Zn0 B0Zn50 B0Zn100 B25Zn50
10
0 f
ruit
wt.
(kg
)
0
5
10
15
20 aab
babab
c
Harvested fruits were higher (19%) in Zn50-B25 compared to control.
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