Agriculture Reference
In-Depth Information
the implements along the correct path. An additional GPS receiver is placed on the
implement to know the current position of the implement relative to the desired
track. Implement control applications include minimizing the drift of large imple-
ments, reducing the downward draft on hillsides, and controlling the effects of roll-
ing terrain on the implement.
5.5.6 A
UTOMATED
T
URNS
After the successful development and employment of automated guidance on agri-
cultural vehicles, the next logical step was to automate turning maneuvers. Creating
a control system to automate turning at headland areas depends on several factors:
headland width, equipment width, tractor dynamics, and the type of turn desired.
The iTEC Pro system (Deere and Company, 2010a) uses tractor and equipment
parameters and headland boundaries input by the operator to automate headland
turns. Once engaged, the system will automatically perform the headland turn once
it has entered a headland area without any input from the operator. An additional
function provided by iTEC Pro is implement control. Control sequences can be set
up for the equipment as it enters and exits the headland area. For instance, as the
equipment enters the headland, tractor speed may be reduced, and the implement
raised. As the implement exits the headland, the implement may be lowered and the
tractor speed increased. Using these two functions included in the iTEC Pro system,
headland turns can be completely automated such that the operator does not need to
steer the tractor nor activate the implement being used.
5.6 INPUT METERING AND PLACEMENT AUTOMATION
On-the-go sensing in agriculture refers to
in situ
, real-time sensing of the plant,
soil, and other biomass properties. Some of the available on-the-go crop health sens-
ing technologies include Topcon's CropSec
TM
(see Figure 5.4) GreenSeeker
TM
, and
CropCircle
TM
. These crop canopy sensors allow the user to create nutrient maps on-
the-go, for fertilizer application management. Nitrogen levels in the sensed crop are
determined using Normalized Differential Vegetative Index (NDVI) measurements.
NDVI measurements range between -1 and 1, where -1 represents the detection of
soil, 0 indicates poor biomass, and 1 represents high biomass content. This mea-
sure of chlorophyll content is correlated to the nitrogen concentration of the leaf.
Fertilizer costs can be reduced with the use of these devices based on plant require-
ments. Site-specific application of nitrogen can be tied to real-time sensing of plant
nutrient status.
On-the-go real-time measurement of electrical conductivity, which correlates
well with soil texture, moisture content, and soil pH, can be performed using Veris
Multi Sensor Platform (Veris MSP). This sensor platform georeferences the soil data
and creates soil maps for site-specific management decisions. Soil compaction is
an important soil property that has an adverse effect on the yields. To date, the soil
cone penetrometer, which provides cone index, is the only standard device available
commercially to measure soil compaction. Collecting compaction data using cone
penetrometer is time consuming and almost impractical for large fields. This issue
