1. Precision agriculture aims to optimize agricultural production by accounting for spatial and temporal variability in soils, crops, and the environment. Key principles include mapping fields, using GPS for precise data collection, yield monitoring, grid soil sampling, remote sensing, and GIS systems. 2. Precision agriculture techniques help quantify on-farm variability related to soil properties, water content, and other factors that impact crop growth. Understanding spatial and temporal scales is important for effective field management. 3. By collecting and analyzing detailed data on yield, soils, and crop conditions within individual fields, precision agriculture helps farmers identify problems and optimize the use of inputs like fertilizer or water on a variable-rate basis. This improves efficiency, productivity and

1. PRINCIPLES AND PRACTICES OF PRECISION
AGRICULTURE

2. 1920
• One
farmer
• 25
People 1960
• One
farmer
• 155
people
2050
• One
farmer
• 265
people

3. PRINCIPLES AND PRACTICES OF PRECISION AGRICULTURE:
1. Mapping
2. GPS receiver
3. Yield monitoring and mapping
4. Grid soil sampling and VRT
5. Remote sensing
6. GIS
7. Quantifying on Farm Variability
8. Soil Variation
9. Variability of Soil Water Content
10. Time and Space Scales

4. 1. Mapping:
• Maps are one of the most effective ways to present data.
• GIS mapping is the process of inputting data layers into GIS
software to produce a map.
• Maps present users with legible information that raw data can’t
display on its own.
• The most crucial and initial stage in precision agriculture is the
creation of maps for crop and soil attributes.
• These maps will measure geographic variability and serve as the
framework for its management.
• The acquisition of exact location coordinates using the GPS improves
data collection both before and during crop production.

6. 2. Global Positioning System (GPS) receivers
• The global positioning system (GPS) is a network of satellites and
receiving devices used to determine the location of something on Earth.
• GPS receivers are programmed to receive information about where
each satellite is at any given moment.
• A GPS receiver determines its own location by measuring the time it
takes for a signal to arrive at its location from at least four satellites.
• Because radio waves travel at a constant speed, the receiver can use the
time measurements to calculate its distance from each satellite.

7. • Since this information is given in real time, it is possible to receive
continuous position updates while moving.
• It is possible to map measurements of soil and crops when one has
access to precise location data at all times.
• Users can return to specified spots to sample or treat certain areas
using GPS receivers, which can be carried into the field or installed
on tools.

8. 3. Yield monitoring and mapping:
• Yield mapping refers to the process of collecting georeferenced
data on crop yield and characteristics, such as moisture content,
while the crop is being harvested.
• Various methods, using a range of sensors, have been developed
for mapping crop yields.
• The information needed for yield maps can be obtained from yield
monitors when connected to a GPS receiver.
• For appropriate management decisions, yield assessments are
crucial.

9. The basic components of a grain yield mapping system include:
1. Grain flow sensor - determines grain volume harvested
2. Grain moisture sensor - compensates for grain moisture variability
3. Clean grain elevator speed sensor - used by some mapping systems to improve
accuracy of grain flow measurements
4. GPS antenna - receives satellite signal
5. Yield monitor display with a GPS receiver – geo reference and record data
6. Header position sensor - distinguishes measurements logged during turns
7. Travel speed sensor - determines the distance the combine travels during a
certain logging interval (Sometimes travel speed is measured with a GPS
receiver or a radar or ultrasonic sensor.)
However, while analyzing a yield map, it is also important to take into account the
soil, terrain, and other environmental elements.
• When used effectively, yield data offers significant feedback for assessing the
effects of managed inputs like seed, herbicides, fertilizer amendments, and
cultural techniques like irrigation and tillage.

10. 4. Grid soil sampling and variable-rate Technology (VRT):
• A group of soil cores collected at random sites within the sampling
region are pooled and evaluated in a lab.
• Based on the results of the soil test, crop experts propose fertilizer
application.
• The same concepts of soil sampling are applied in grid soil
sampling, however sampling intensity is increased.

11. • The geographic location of soil samples gathered in a systematic
grid also provides the ability to plot the data.
• The creation of a map of nutrient requirements is the aim of grid
soil sampling.
• A crop nutrient requirements are interpreted for each soil sample
after laboratory analysis of grid soil samples.
• The whole collection of soil samples are then used to plot the map
for applying fertiliser.
• A computer that is mounted on a variable-rate fertiliser spreader
has the application map loaded into it.
• The computer instructs a product-delivery controller to alter the
quantity and/or type of fertiliser product in accordance with the
application map by using the application map and a GPS receiver.

12. 5. Remote sensing:
• The process of acquisition of information about an object or
phenomenon without making physical contact with the object is called
remote sensing.
• Data sensors might be simple hand-held gadgets, aircraft mounts, or
satellite-based systems.
• The use of remotely sensed data can be used to assess the health of
crops. In aerial photographs, plant stress resulting from moisture,
nutrients, compaction, crop diseases, and other issues with plant health
are frequently visible.
• Near-infrared pictures captured by electronic cameras have a strong
correlation with healthy plant tissue.
• When used in a timely manner, remote sensing can identify in-season
variability that influences agricultural output and help managers make
adjustments that will increase the profitability of the currently
harvested crop.

13. • Crop stress can be located and measured using remotely sensed
photographs.
• Analyzing these photos can assist identify the root cause of specific
crop stress factors.
• A spot treatment strategy that maximizes the usage of agricultural
pesticides can then be created and put into action using the
photographs.
• The most common method is to take pictures using satellites like
LANDSAT or SPOT.
• In order to calibrate the measurement and generate maps, it is
assumed that measurements are made with ground truth accuracy.
• In order to track seasonally fluctuating crop yield, stress, weed
infestation, and extent within a field, these photos enable mapping
of crop, pest, and soil attributes.

14. 6. Geographic information systems (GIS):
• A geographic information system (GIS) is a computer system for
capturing, storing, checking, and displaying data related to positions
on Earth’s surface.
• The ability to record layers of data, including yields, maps from soil
surveys, data from remote sensors, crop scouting reports, and
measurements of soil nutrients, is a key feature of an agricultural
GIS.
• The GIS may display data that has been georeferenced, giving
interpretation a visual element.
• By merging and modifying different data layers, the GIS may be
utilised to analyse different management scenarios in addition to
storing and displaying data.

17. 7. Quantifying on Farm Variability:
• Grain yield often varies within agricultural fields as a result of the
variation in soil characteristics, competition from weeds,
management practices and their causal interactions. To implement
appropriate management decisions, yield variability needs to be
explained and quantified.
• Each farm provides a different management problem.
• SSNM, SSWM, STCR, etc…
• It would be too expensive to instantly adopt all of the methods
mentioned above, and not all of them will be useful in identifying
the reasons of variability in an area.
• The best course of action is to take a gradual approach, employing
one or two instruments at a time and carefully assessing the
outcomes.

18. 8. Soil Variation:
• A spatial variable is soil variation.
• Soils vary continuously within fields and between farms. Surface
variation may be easily seen, but nutrient variability is usually not
obvious.
• This field could be extended with other variables to produce a
network of interconnected components.
• Soil sampling strategies for site-specific nutrient management are
based on grid sampling or zone sampling.
• Satellite imagery quality and pixel, Aerial Imagery, Electromagnetic
Sensors, Multiyear Yield Maps

19. 9. Variability of Soil Water Content:
• It is a known fact that the amount of water in the soil changes over
time and place in a field, and this temporal and geographical
variability in soil water content patterns.
• Variability of soil water content can result from spatial differences
in soil parent material, plant transpiration, erosion, compaction and
other processes that affect soil structure.
• A solid foundation for precise water management may be
established by understanding the underlying stable soil water
distribution, which would also result in energy, water, equipment,
labour, and production efficiency savings.

20. 10. Time and Space Scales:
• Precision Agriculture requires an understanding of time and space scales.
• Time scales are critical because operations occur when they will benefit
the crop most.
• Space scales become a fundamental principle of field management
because inputs and cultural practices are varied with soil type, pest
population, or crop maturity.
• The challenge is to determine how to use time and space scales to
advantage in developing an improved understanding of agricultural
management.
• To fully achieve the goals of precision agriculture, management must be
applied in a space and time context.
• The challenge of monitoring in space and time is important to document
the changes that are naturally occurring within a field.
• To fully realize the potential impact of principles of precision agriculture
on environmental quality, however, will require the design and
implementation of experiments in space and time.