Agriculture Reference
In-Depth Information
computers and their peripherals, and networking equipment make it possible to auto-
mate many operations on information collection, communication, analysis, and deci-
sion making to agricultural practice. However, despite considerable efforts to achieve
fully automatic worksite management systems, many challenges continue to exist.
New electronics and networking technology stimulate the rapid development of
signal conditioning, processing, communication, and user interface systems within
the smart sensors/controllers/actuators. As the predominant component in a mea-
surement system, however, sensors are still the bottleneck of overall performance.
Sensors for some physical parameters are well developed, such as temperature and
light. But others for soil properties and plant properties are lagging far behind.
Although soil moisture sensors are becoming mature on the market, N, P, K concen-
trations, heavy-metal contents, and organic matter measurements of soil still heavily
depend on analytical methods, which are tedious and time-consuming. Many crop
sensors are designed for specialty crops or tree crops, such as leaf temperature, sap
flow sensor, and stem diameter sensor. High-resolution, on-the-go sensors for grain
and forage crops are still underdeveloped and under-commercialized. Disease detec-
tion in plants still relies on empirical data or subjective human evaluation. For exam-
ple, field scouting for visible symptom is the main method to detect Huanglongbin
disease in citrus orchards. Although biological and physical characteristics have
been discovered that are associated with Huanglongbin disease, there are still no
effective sensors available.
The development of these sensors requires interdisciplinary knowledge from
soil scientists, plant scientists, engineers, agronomists, entomologists, etc. The new
advanced technologies provide tools with higher throughput, higher resolution, more
channels, lower noise and interference, and more functions. Hence, they provide
great opportunities for new sensor development.
To be used in agricultural and food production, any sensing and control systems
need to maintain reliable and stable performance under various environmental con-
ditions, many of which are unpredictable. The temperature variations can be very
significant, which make the systems often run under extreme conditions. Sunshine,
rain, snow, and wind can also significantly affect the system performance. Wild
animals and thefts can cause damage to the systems. Regular field operations, such
as tillage, chemical applications, and harvesting, may interrupt stationary systems
installed in a field. Dust, plant canopy, and mechanical parts can be a potential dis-
turbance to sensing systems. Hence, special considerations are needed for packag-
ing, installation, and protection of the deployed systems.
To realize real-time worksite management, communication between field systems
and a management center need to be well maintained. The sensor nodes and control
nodes installed in a field need not only perform measurement and control tasks, but
also communicate with other nodes and sink nodes for data transfer. In most remote
field applications, sensor and control nodes depend on their own power source, com-
monly a battery, to complete their tasks and continue to operate for a certain length
of time. This requires all the system components to consume as less power as pos-
sible. Minimizing the power consumption should be considered at each development
stage of hardware, software, and communication protocols. The agricultural field
environment is full of natural energy sources. Using a more active approach, sensor
