Precision agriculture is an art and science of utilizing innovative, site-specific techniques for management of spatial and temporal variability using affordable technologies… for enhancing output, efficiency, and profitability of agricultural production in an environmentally responsible manner

1. Dr. Basavaraj Patil
Centre for Natural Resource Management
National institute of Rural Development and Panchayati Raj,
Hyderabad

2. Precision agriculture is an art and science of utilizing innovative, site-
specific techniques for management of spatial and temporal
variability using affordable technologies… for enhancing output,
efficiency, and profitability of agricultural production in an
environmentally responsible manner
• “... changing the traditional process of farming by the square mile to
farming by the square meter…”
What is Precision Farming ?
Traditional Mgt. Precision Mgt.

3. Objectives
 Efficient use of Inputs
 Increased Production Efficiency
 Improved Product Quality
 Conservation Energy
 Soil and Ground Water Protection

4. components

5. Global Positioning System in Precision Agriculture
• The global positioning system ("GPS") is a network of satellites developed for
and managed by the U.S. Defense Department.
• The GPS constellation of 24 satellites orbiting the earth, transmit precise
satellite time and location information to ground receivers.
• The ground receiving units are able to receive this location information from
several satellites at a time for use in calculating a triangulation fix thus
determining the exact location of the receiver.

6. •Remote sensing refers to the process of gathering information
about an object, at a distance, without touching the object itself
•The most common remote sensing method that comes to most
people's minds is the photographic image of an object taken with
a camera
•Remote sensing has evolved into much more than looking at
objects with our eyes
• It now includes using instruments, which can measure attributes
about objects which unaided human eyes can't see or sense
Remote sensing

7. Variable rate technology ("VRT") consists of farm field
equipment with the ability to precisely control the rate of
application of crop inputs and tillage operations.

8. Practical steps include a cyclic process
(a) Characterization: measure extent, scales and dynamics of variation,
(b)Interpretation: assess significance, identify major causes of
uncertainty and formulate management targets
(c) Management: apply inputs at the appropriate scale and in a timely
manner
(d) Monitoring the outcome in a continuous learning process of change.
This may be accomplished in discrete steps (mapping approaches), as
dynamic process executed in real-time (sensing approaches and
modeling approaches) or as combination of both is also possible.
Steps in precision farming

9. Characterization and Management
of
Variability
Spatial Temporal
Soils & Crops

10. Interpretation
Management
Characterization
Monitoring
CYCLIC
PROCESS OF PNM

11. Steps in the Cyclic Process:
1.Characterization
Measure : Extent,
Scales & of variation
Dynamics

12. 2. Interpretation
 Assess Significance
 Identify major causes of uncertainty
 Formulate management strategies

13. 3. Management
Apply right inputs: Source
Rate
Time &
Method

14. 4. Monitor the Outcome
 Economic Benefits
 Environmental Impact
 Sustainability

15. Methods of Precision Farming
Map based
-It includes grid sampling a field
-Generating a site specific map of the properties and finally using this map to
control a variable rate applicator
-GPS/DGPS is used to identify the current location with higher accuracy in the
field
-Site specific maps may also be used for grid wise site specific input management
-This methodology is most relevant for Indian agriculture at present
Sensor based
-It utilizes real time sensors and feed back control to major the desired properties
-Sensors developed for on-the-go real time measurement of soil properties have
the potential to provide benefits from increased density of measurements at a
relatively low cost
-GPS receiver and a data logger are used to record the position of each soil sample
or measurement
-To generate a map which can be processed along with other layers of spatially
variable information to control the variable rate applicator

16. Map based and Sensor based precision farming
Sl
No.
Parameters Map based Sensor based
1 Methodology
Grid Sampling - lab analyses
-
site specific maps and use of
variable rate applicator
Real time sensors – Feedback
control measures and use of
variable rate applicator
2 GPS/DGPS Very much required Not necessary
3
Laboratory analyses
(Plant & Soil)
Required
Not required
4 Mapping Required May not required
5 Time consumption More Less
6 Limitations
Cost of soil testing and
analyses
limits the usage
Lack of sufficient sensors for
getting crop and soil
information
7 Operation Difficult Easy
8 Skills Required Required
9 Sapling unit 2 to 3 acres Individual spot
10 Relevance
Popular in Developing
countries
Popular in Developed
countries
Patil and Shanwad, 2004

17. Issues related to precision nutrient management in
developed & developing countries
Farming situation Developed countries Developing countries
Farm size Big Small
Soil fertility High Low
Fertilizer usage High Low
Yield levels High Low
Profitability High Low
Risks Low High
Farm machinery High end Low end
Precision farming Complicate Simple
Techniques GPS,GIS, RS LCC, SSNM
Relevant PNM tech
Real time and sensor
based
Discrete & Image based
Patil, 2009

18. Why is Precision Nutrient Management Important?
• Nutrient variability within a field can be very high
(graphs to follow), affecting optimum fertilizer
rates.
• Yield potential and grain protein can also vary
greatly even within one field, affecting fertilizer
requirements.
• Increasing fertilizer use efficiency will become
more important with increasing fertilizer costs and
environmental concerns

19. 4R's Nutrient Stewardship
Applying the “right fertilizer” source at the “right
rate”, “right time”, and “right place”

20. What is the site-specific nutrient management
approach?
• It emphasizes ‘feeding’ crop with nutrients as and
when needed.
• Fertilizer used to fill the deficit between the nutrient
needs of a high-yielding crop and the nutrient supply
from naturally occurring indigenous sources (soil,
organic amendments, crop residues, manures and
irrigation water).
• It aims to apply nutrients at optimal rates and times to
achieve high yield and high efficiency of nutrient use
by the crop.

21. The concept of SSNM for rice was developed in the mid-
1990s and then evaluated from 1997 to 2000 in about 200
irrigated rice farms at eight sites in six Asian countries.
Site Specific Nutrient Management is defined as the
dynamic, field-specific management of nutrients in a particular
cropping season to optimize the supply and demand of
nutrients according to their differences in cycling through soil-
plant systems.
(Dobermann and white, 1999)
Site Specific Nutrient Management (SSNM)

22. Principles

24. Principles of SSNM
Principles of SSNM are generic and applicable to other
crops
• SSNM provides an approach for feeding crops with
nutrients as and when needed.
• Optimal use of existing indigenous nutrient sources,
including crop residues and manures
• Timely application of fertilizers at optimal rates to meet
the deficit between the nutrient needs of a high-
yielding crop and the indigenous nutrient supply
(Witt et al., 2009)Philippines

25. (Daniel et al., 2009)Purdue University

30. Variable Rate Applicator

31. For the need based N application, reliable diagnostic tools are needed to
inform farmers how much and how often to apply N fertilizer.
Leaf colour chart could help farmers easily to identify the greenness of rice
leaves to make their decision on when and how much N fertilizer needed for
their crops.
The LCC is usually a plastic, ruler shaped strip containing four or more
panels that range in colour from yellowish green to dark green.
Farmers then apply fertilizer N whenever the leaves are more yellowish
green than a threshold LCC value, which corresponds to a critical leaf N
content.
Leaf Colour Chart

32. How to Use the LCC
1. Start LCC readings from 14 days after transplanting (DAT) or 21 days after
sowing (DAS). Take the last reading when the crop just starts to flower.
2. Randomly select at least 10 disease-free rice plants or hills in a field with
uniform plant population. Select the topmost fully expanded leaf from
each hill or plant
3. Place the middle part of the leaf on a chart and compare the leaf color with
LCC shades. When the leaf color falls between two shades, the mean value
is taken as the reading, e.g., 2.5 for color between 2 and 3. Do not
detach or destroy the leaf

33. 4. Measure the leaf color under the shade of your body, because direct sunlight
affects leaf color readings.
5. Repeat the process at seven to ten days intervals or at critical growth stages
(early tillering, active tillering, panicle initiation and first flowering) and
apply N as needed.
6. If more than five out of ten leaves read below a set critical value, apply:
􀁺 20-30 kg N/ha for wet season or low-yielding season
􀁺 30-35 kg N/ha for dry season or high-yielding season

34. • Set realistic yield goals and apply
nutrients to meet the target yield.
• Omission plots
• Soil testing
• Right rate
• Right time
• Right place
• Greater synchrony between crop demand and nutrient supply
• Split application vs. single application is more effective
• Diagnostic tools
Application of nutrient for achieving optimum nutrient efficiency
Chlorophyll meter
Leaf colour chart

35. -20 -10 0 10 20 30 40 50 60 70 80 90 100 DAT
Transplanting Harvest
Take LCC readings
every 7 days
Early
Within 14 DAT 21–50 DAT
High-yielding season
Yield target = 7 t/ha
Low-yielding season
Yield target = 5 t/ha
30 kg N/ha
0 to 20 kg N/ha *
If LCC < 3.5 **
45 kg N/ha
If LCC < 3.5 **
23 kg N/ha
* Early N is not essential but up to 20 kg N/ha can be applied when NPK fertilizers are used to supply P and K.
** Leaf color is nearer to LCC reading 3 than 4 with standardized IRRI LCC
23 kg N/ha = 1 bag urea/ha; 45 kg N/ha = 2 bags urea/ha.
Active
tillering
Panicle initiation
(PI) Heading
Example of a real-time N recommendation

36. • Canopy spectral reflectance - making the measurement of a
crop’s N status quicker than using the SPAD meter.
Reflectance of Leaves for Visible Light and Near Infrared
•High reflectance (40 to 60%) for NIR (800 to 1300 nm wavelength)
light because of internal leaf scattering and no absorption of NIR.
•NIR reflectance increases from a low reflectance (7 to 50%) at
heading
•NIR/green ratio is linearly related to leaf N accumulation
Texas, USA (Wilson, 2008)
Potential for Improving Nitrogen Recovery
Through Remote Sensing

37. Using Reflectance to Estimate of N status and N Fertilization
Rate
 Three methods of estimating top dressing rates were tested - Canopy
density (LAI), Nitrogen nutrition index (NNI) and N fertilizer
optimization algorithm (NFOA).
 A non-significant trend suggests the NFOA method resulted in higher
grain yield than the other estimation methods and the standard N
application rate.
 Highest N recovery efficiency which was 58% compared to 43% for the
standard N application rate.
Texas, USA (Wilson, 2008)

38. (Biradar, 2004)
Fig. 7: Site-specific nutrient management studies in Karnataka

39. Vegetation Indices (NDVI)
Normalized Difference Vegetation Index (NDVI)
NIR- Red
NDVI = ----------------
NIR + Red
Where: NIR – Broad band NIR reflectance
Red – Broad band Red reflectance.
NDVI has very high correlation with LAI and crop yield.

40. SSNM in different countries
Crop
(Country)
N Treatment
N
applied
(Kg/ha)
N Saved
(Kg/ha)
Yield
(t/ ha)
NUE
(Kg/Kg)
Maize
(USA)
Conventional
SSNM 1
SSNM 2
142
141
113
-
+1
+29
10.3
10.4
10.4
73
74
90
Rice
(Philippines)
Conventional
SSNM
130
87
-
+43
7.6
7.5
58
86
Rice
(China)
Conventional
SSNM
171
126
-
+45
6.0
6.4
37
52
Rice
(India)
Conventional
SSNM 1
SSNM 2
142
110
108
-
+32
+34
4.6
5.0
4.9
34
45
45

41. Dissemination tools for SSNM
“Nutrient Expert”- Maize (Developed by IPNI south east Asia)
“Nutrient Manager”- Rice (Developed by IRRI)
GIS based fertility maps-(Initiated by IPNI south Asia)
Computer -based decision support
tools to address the SSNM

45. Micro irrigation

49. Water Movement

50. Fertigation Comparison

51. Fertilizer Injection

52. Fertigation Injection Devices

53. (i) Making the interpretation process more automatic, generic and
mechanistic as against empirical
(ii) Location-specific RS solutions for integrated crop management
program
(iii) Developing simple and robust technologies and methodologies
(iv) Evaluation at multiple sites with standardized methodologies
providing proof of economic and environment benefits
(v) Customization of the precision farming technology to the actual
Indian field conditions.
Major challenges that are to be faced before realizing
the real benefits from precision nutrient

54. (i) Horticultural, plantation crops and other high profit making
crops
(ii) Precision management of nutrients, water and other inputs in
irrigated agriculture and
(iii) Forecasting incidence of pests & diseases and management in
commercial crops and in crops such as paddy, cotton, pigeon
pea, chickpea etc, where huge quantities of pesticides are used.
Priority area for the immediate implementation of
precision farming technologies