Satellite data and computers can be used to monitor
the state of Pakistan's agricultural resources. The use of electronic
information technology for agricultural resources management is
gaining interest. It makes agriculture management less tedious and
costly, by collecting a wider spectrum of data in a much shorter span
of time. This is far departure from labour and time-intensive
traditional on-site surveys and monitoring approaches. Now exciting
opportunities are emerging in precision agriculture, GIS-based mapping
and modelling of soil erosion — using satellites to monitor changes
in land use and disseminating the information.
As the world's population continues to grow,
humankind is faced with the onerous task of meeting the world's food
demand. This can only be accomplished with sustainable agriculture.
Sustainable agriculture requires a delicate balance between crop
production, natural resources use, environmental impacts and
economics. The goal of sustainable agriculture is to optimize food
production while maintaining economic stability, minimizing the use of
natural resources and minimizing impacts on the environment. The use
of electronic information technology for agricultural resources
management is gaining interest among researchers throughout the world.
It is one of the tools that can be used by Pakistan in its bid to use
its natural resources sustainably.
Some countries including Japan are already making
advanced use of this technology. Other countries are still in the
process of evolving a baseline data, while building their human
resources to strengthen their technology capability in the future.
Both group of countries need to continue exploring
the merits of this technology, with the aim of counteracting the
negative effects of development, such as soil erosion, soil salinity,
soil pollution and flooding. Unless these can be reversed, they will
cumulatively reduce the carrying capacity of land and soil resources
over the years. Electronic information technology is a significant
tool to help countries manage their land and agricultural resource
sustainably, restoring their productivity for future generations. Some
of the uses of this technology are:
Precision agriculture (or site-specific
agriculture) utilizes rapidly evolving electronic information
technologies to modify land management in a site-specific manner as
conditions change spatially and temporally. The intent of precision
agriculture is to optimize crop production while minimizing
detrimental environmental effects. First conceived in the mid-1980s,
the technological pieces needed to bring precision agriculture into
its own fell into place in the mid 1990s with the maturation of global
positioning system (GPS) and geographic information systems (GIS). As
such, precision agriculture is technology driven system. The future of
precision agriculture rests on the reliability, reproducibility, and
understanding of the technological developments on which it is based.
WHAT IS PRECISION FARMING?
The term "precision farming" or
"precision agriculture" is capturing the imagination of many
people concerned with production of food, feed and fiber. It offers
the promise of increased productivity, while decreasing production
costs and minimizing the environmental impact of farming. Precision
farming was originally developed for large farming units, such as
those found in the United States. More recently, it has been adapted
to the needs of small-scale farms in Asia, which in some countries
have average size of only one hectare (2.6 acres).
ELEMENTS OF THE TECHNOLOGY
There are three fundamental elements in this
(A) DESCRIBING VARIABILITY
Describing variability is the key concept.
Variability should be understood in at least three aspects; spatial,
temporal and predictive. This variability includes both the range of
variation in individual fields, and the variation found between fields
in the area or region where the system is being applied.
(a) Real-Time Soil Sensing:
Japan has recently developed automated ways to know the variability
within the fields, using a real time soil sensing. Portable soil
organic matter sensor with photodiodes using a single wavelength is
developed. It gave good results in predicting soil organic matter in
the range 1.5-6 percent. The feasibility of spectral reflectance to
sense soil organic matter is also investigated.
A potable NIR spectrophotometer was designed to
evaluate soil organic matter, cation exchange capacity and moisture
content in a ploughed soil at a depth of 3.5-5 cm. This approach can
be useful to get information about the field surface, but they still
need in situ soil sensing in the zone of root development for
practical use in crop management. They have developed a real-time soil
spectrophotometer with an RTK-GPS to sense underground soil parameters
at a depth of 15-40 cm.
The objective of this work is to use the soil
spectrophotometer to generate soil maps of field, for the
implementation of precision farming. The sensor system is composed of
three main units — the external housing, the soil penetration and
probes, and the external sensing and monitoring devices. Data scanning
time is just over four microseconds. Integration of scanned data is
carried out for each individual scan to get average values. A video
data recorder on the tractor displays images of the soil surface.
Satellites are used to collect the data.
(b) Use of soil electrical conductivity in
precision agriculture: From a
global perspective, irrigated agriculture make an essential
contribution to the food needs of the world. While only 15 percent of
the world's farmland is irrigated, roughly 35 to 40 percent of the
total supply of food and fiber comes from irrigated agriculture.
However, vast areas of irrigated land are threatened by salinization.
Although accurate worldwide data are not available, it is estimated
that roughly salinity and water logging affect half of all existing
irrigation systems. Salinity within irrigated soils clearly limits
productivity in vast areas of the Pakistan and other parts of the
world. It is generally accepted that the extent of salt-affected soil
is increasing. In spite of the fact that salinity buildup on irrigated
lands is responsible for the declining resources base for agriculture.
We do not know the exact extent to which soils in our country are
salinized, the degree to which productivity is reduced by salinity,
the increasing or decreasing trend in soil salinity development, and
the location of contributing sources of salt loading to ground and
drainage waters. Suitable soil inventories do not exist, and until
recently, neither did practical techniques to monitor salinity or
assess the impact of changes in management on soil salinity and salt
loading. A mean of assessing soil salinity across the landscape is
essential to management of soil salinity. Because of the influence of
soil salinity on crop productivity and the dynamic spatio-temporal
nature of salinity, real-time measurement and monitoring of the
spatial and temporal distribution of soil salinity is a crucial piece
of information for precision agriculture application on irrigated
agricultural soils. Soil EC is determined by standardizing measures of
soil conductance by volume of soil through which current travels.
Traditionally, soil paste EC has been used to assess soil
conductivity, but commercial devices are now available that can be
used to rapidly map bulk soil EC across agricultural field through
direct contact or induction techniques.
(B) VARIABLE-RATE TECHNOLOGY (VRT)
This is used to adjust the agricultural inputs
according to the site-specific requirements in each part of the field.
If machines are used, this requires variable-rate machinery. On small
farms, inputs can be applied manually. Variable-rate applications
— Correct positioning in the field;
— Correct information at the location; and
— Timely operations at the site concerned.
Variable-rate technology not only increases
productivity by re-organizing the three factors of technology, plants
and fields, but also creates better linkage with regional
infrastructures, e.g. by following environmental regulations.
(C) DECISION-SUPPORT SYSTEM (DSS)
Decision support system offer a range of choices to
farmers with respect to trade-off problems where conflicting demands
must be taken into account, such as productivity and protection of the
environment. This approach helps to optimize the whole farming system.
A decision support system provides the best technology, taking into
account the aims and motivation of farmers as well as environmental
factors. In other words, precision farming brings about an innovation
in the whole system of agriculture. It is possible to apply precision
farming to small as well as large farms, and make it part of rural
This technology is now being developed to help
small -scale rice farmers in Taiwan to improve their fertilizer
applications. Although Taiwan has a strong island-wide soil testing
service, some rice farmers in Taiwan do not know the nutrient status
of their soils, particularly with regard to nitrogen, phosphorus and
potassium. Decision support systems are being developed which will be
able to provide site-specific fertilizer recommendations.
A number of agricultural organizations in Taiwan,
including agricultural universities, and government research
institutes have established various systems. They are web-based GIS
system which attempt to share and disseminate information and soil
properties to potential users particularly agronomists, extension
staff and leading farmers.
GIS-BASED MAPPING AND MODELLING OF SOIL EROSION
Conventional surveys of soil erosion in the field
are costly in time and labor. All soil survey are labor-intensive, but
surveys of erosion usually have to cover several years, to get a
reliable estimate of the rate of soil erosion and the main factors
influencing it. GIS-assisted physical model are now available which
can predict where erosion "hot-spots" are likely to occur.
The model could thus be used to identify sites, which were very
vulnerable to erosion, and where conservation measures were urgently
GIS could also be used to predict the effects of
surface cover on the discharge of water and soil sediments from the
USING SATELLITES TO MONITOR CHANGES IN LAND USE
All governments have legal restrictions concerning
the use of public land, especially the cutting of forest, and the
conversion of forest to arable land. In practice, it is difficult to
monitor what are usually remote areas, and detect changes in land use
at an early stage before environmental damage has become serious.
Satellite remote sensing is an effective way of monitoring resource
management and changes occurring over large areas. This type of
analysis is also very useful for showing the sustainability of
different agricultural systems Policy makers can only promote
sustainable land use systems if they know which ones they are. GIS
facilitates the classification of land into different land use
classes, and can monitor the long-term impact of different kinds of
land use. In this way, policy maker's can be helped to distinguish
land where agriculture can be intensified or expanded, from land where
rehabilitation and diversification are needed. The information from
GIS is now becoming detailed enough to show which areas are suitable
for specific crops.
Farmers and electronic technology
In discussion of sustainable land use, there is
often a conflict between the wishes of policy makers and needs of
farmers. Policy makers wish to make their nation's use of resources
sustainable, and take a broad view of the country's economic
development. Farmers have an immediate need to support their families.
Farmer's response to this technology is more positive if they are
consulted during the development of GIS-based programs. Participatory
consultation is now becoming an important part of GIS programs.
Farmers can also be a key source of information.
Often the local knowledge of farmers is more relevant and useful than
the academic knowledge of scientists. GIS can also show gaps in
infrastructure, such as scarcity of roads or marketing centers, that
may cause agricultural development programs to fail in an area which
otherwise seems suitable. The great benefit of GIS and DSS is that
they can provide site-specific information, including recommended
practices. This also a challenge, in that it is difficult to
disseminate detailed information of this kind to specific farmers.
Korea and Taiwan are pioneering the use of
information technology in environmental management for agriculture.
Sources of data are land use surveys, aerial photographs, detailed
soil survey maps etc. Maps are generated from these sources and
encoded in central computers. The system is linked to related
institutes and centers throughout Korea and Taiwan, and is then made
available on the Internet.
Internet users, including farmers or extension
staff, can easily find information at a provincial, county or district
level. Information includes land use, drainage, soil type, soil depth,
and soil chemical properties. Recommendations for each type of land
use are also being provided for farmers and other clients.
agricultural producers are currently facing low crop prices. These are
likely to fall even lower because Pakistan has joined WTO.
Site-specific nutrient management is new approach to productions,
which may replace current uniform rate technology. It offers the
promise of increasing productivity, while decreasing production costs
and minimizing the environmental impact of farming. It is important to
develop and use this technology in Pakistan, because this is feasible
for both large and small farms.
2. From the
point of view of development in rural areas which includes small farms
and local companies, precision farming offers the possibility of
developing of a new kind of industry, by fusing agriculture to various
kinds of industrial activity. If these multi-functions of agriculture
are re-evaluated using information-added fields, value-added space of
this kind can be seen as providing new sources, such as biological
materials, open-air classrooms and eco-tourism.
adopting electronic information technology, it is necessary to
identify the specific clientele whom it will be serving. These may be
small or large-scale farmers, extension staff, or institutions that
will be adopting this technology. Will these be the small or
large-scale farmers, the extension worker or an institution?
4. Crop or
soil management based on this technology should have the marketing
aspect and risk management factored in.
benefit of participatory development of this technology should be
developing an electronic information technology based system, a
decision needs to be taken about the best mode of information
dissemination, based on the country's present situation. This might be
a decision support system (DSS), stand-alone or web pages.
Pakistan SUPPARCO may take a leading role for development of
infrastructure for the use of this technology.
private sector or government organizations should develop joint
venture with other leading countries in this technology.
The author is from Department of Agronomy,
University of Agriculture, Faisalabad. E-mail: email@example.com