Agriculture Reference
In-Depth Information
Table 3.2
Feasible applications for sensing of soil-and plant properties by radiation
Radar waves
Visible- and/or infrared waves
Proven applications
Volume or height of crops
Plant constituents,
e.g.
chlorophyll, water and nitrogen
Vertical- and horizontal arrangement
of plant parts
Leaf-area-index of crops
Roughness of soil surface
Senescence of crops
Moisture of soil layer of a few cm
Organic matter and water on soil surfaces
Emerging applications
Classifi cation of crop species
Classifi cation of crop species
Fresh biomass of crops
Soil texture on the surface
Dry biomass of crops
Soil content of some nutrients on the surface
getting information about
synoptical properties
,
e.g.
the volume of crops or
the roughness of soil surfaces. Yet the items listed in Table
3.2
should not be
regarded as strict limits (Kühbauch
2002
).
3.6
Using Maps or On-The-Go Control in Real-Time
Aside from sensing limits, there are distinct differences in the domains of applica-
tions for properties that are recorded from satellites or from farm machines. Polar
satellites can provide for maps that show the situation for a large area at a defi nite
hour within a day. Machine based sensors never can do this.
There is a need for maps that provide for an
overview
of soil- and crop condi-
tions at a defi nite time within a farm, a community, a county or a whole country. So
overviews about
e.g.
soil water supply, fi elds that are fallow or cropped, crop spe-
cies used, crop development, crop damage of various kinds (hail, drought, fl oods,
diseases, insect infestation
etc
.), progress of harvesting and subsequent cultivation
can be helpful. The present state of the art in sensing from satellites or aerial plat-
forms allows not yet to provide all of these details despite the fact that the possibili-
ties increase steadily. In many instances, combining of several radiation phenomena
is needed in order to get to the desired information. Accordingly, McNairn et al.
(
2009
) as well as Shimoni et al. (
2007
) have provided for methods in order to clas-
sify or identify crops that are grown in an area either by using visible- plus infrared
radiation or by taking radar waves.
However, the information that is helpful differs. Governmental departments,
farm agencies and agribusiness institutions need maps that provide for information
over wide areas that include many farms. Farmers primarily require maps that either
contain just the whole own farm or even are limited to a single fi eld. So it is reason-
able to differentiate between
wide area maps
farm maps and
fi eld maps.
