TO PRECISION FARMING AND ROLE OF NANOSENSORS IN PRECISION FARMING.
: Pranay Ahuja
farming is a system based on Information and technology which helps in
detecting and analysing the variability in agricultural fields for optimum
profitability, sustainability and protection of the land. This is done by
controlling and monitoring the field application rates such as yield,
application rates etc. about every 3 feet in the field at a low cost. The main
objectives of the Precision farming are;
® To increase Profitability and
® To improve Product quality
® To conserve water
® Effective Pest Management
can be applied in only needed areas, for ex : areas of pest infestation, which
reduces the amount of pesticide and reduces the harmful effects of pesticides
on the environment.
factors that are measured with the help of precision faming are;
® Pest Population
® Moisture Content
® Soil Texture
The 3 main
elements of Precision Farming are;
® Decision management
components of Precision Farming are;
® Crop Scouting
used in Precision Farming;
® GPS: Global Positioning System is a set of 24 satellites
that are placed in earth’s orbit to carry out radio signals that are processed
by ground’s receiver to determine the position of receiver on earth.
® GIS: Geographic Information System is a software that
sends, receives and processes data that are spatially distributed.
® Remote Sensing : It is a software that measures the
characteristics of the field without having contact with the characteristic
that is being measured.
® Scouting : This means going through a field
and analysing it to determine levels of pest infestation and crop development.
® Grid Soil Sampling : It involves breaking of land into
grids (1-2.5 acres) where soil sampling is done to determine appropriate
® Yield Map : Map for determining the
variability in the field. The map is created using GPS and yield monitor.
® Variable Rate Application : It is an equipment that contains
controllers used to vary fertilisers, pesticides etc. as measured by the
application map using ‘on-the-go sensor’.
‘On the go’ sensors, or soil organic matter measures the
characteristics of the soil before planting and adjusting the seed rate.
Role of Nanosensors in Precision Faming
Nanosensors are emerging as a useful tool for applications in
food & agriculture industry. They show improved Selectivity, Sensitivity
and speed as compared to traditional methods. Nanosensors can have application
in determination of microbes, food pollutants etc. It can also be used to
monitor environmental stresses and variability. For ex : Moisture level, soil
fertility etc. These sensors are also capable of detecting and responding to
physicochemical signal and biological signal, and transferring the response
into a signal that can be used by humans.
There are many sensors that can be used in Precision Farming;
® Sensors for pathogen detection : The sensors are classified into ;
a) Direct Methods for Pathogen Detection
b) Indirect Methods for Pathogen Detection.
Direct Methods include
detection of the pathogen itself whereas Indirect Methods include detection of
effect of pathogen on plant behaviour.
For ex : a) Immunological
Techniques using Antibodies or Antigens
b) Molecular Techniques using Acid based Probes are direct methods,
whereas Spectroscopic techniques and Volatile Organic Compounds Detection
methods are indirect methods.
1.) Nucleic Acid Based Probes : The genomic DNA is extracted from
bacteria with the help of thermal. The Genomic DNA is denatured to obtain a
single stranded DNA which is then hybridised using biotinylated single strand
to which a capture probe is attached. To this capture probe,
streptavidin-magnetic bead is attached. The target DNA is amplified and
hybridised and electrodes with immobilised DNA probe is obtained. The
Streptavidin-Au nanoparticles are added which attaches to the capture probe of
theTarget DNA and confirms presence of analyte.
2.) Immunological Technique :
A sandwich model of antigen antibody detection can be used where a
capture antibody captures the analyte and the analyte is then attached to a
secondary antibody containing biotinylated to which streptavidin coated
nanoparticle attaches and confirms the presence of analyte.
® MEMS Based Sensor for measuring
moisture : The
Irrigation Management Systems should have information about soil moisture at
root level of plants. This helps in providing Irrigation Water in an efficient
way. Therefore, Microelectromechanical systems based on Nanotechnology can be
used which is a collection of micro and nanosensors. These sensors help in
sensing the environment and can also react to changes in environment with the
help of a circuit control.
The MEMS Sensor is based on a shear-stress principle for
measuring water vapour in which the microsensor chip combines a wheatstone
bridge piezo-resistor circuit to deliver DC voltages that are proportional to
relative humidity. A water vapour sensitive nanopolymer film is bonded on a
cantilever that expands and contracts when water vapour is exposed.
Because of the high surface area of nanoparicles which improves sensitivity,
selectivity etc. of the sensor,
Nanosensors are a very handle tool in Precision Farming and these sensos help
in identify, analyse & manage variability in a much more efficient manner
which increases profit, makes the resource more sustainable and protects the
land in a better way.