Grain Guide 2017

GRAANGIDS

2017

GRAIN GUIDE

Where does one start with

precision farming?

Precision farming involves the area-specific

adaptation of production techniques on the

basis of geographical data on chemical, physi-

cal and morphological soil properties, but also

other geographical production data like yield

data and growth indices gathered through

remote sensing. The ultimate aim is to run the

farm in a sustainable manner.

But where do you start?

Conversion to precision farming does not

necessarily have a specific starting point and

course, but all the methods have the gather-

ing of geographically linked data that affects

production in common. The availability and

cost of geographical data and equipment on

implements usually play a significant role at

the start of the conversion. Geographical data

refers to specific points on the ground and

for this reason contains two co-ordinates. The

co-ordinates have a longitude and latitude

and sometimes also contain the altitude. The

data is stored in a geographical database

and can contain various other data elements

too. Examples of these can be: Soil depth,

texture, water retention capacity, yield and

plant nutritional status. Satellite images and

other remote-sensing images also contain

geographical data, while images obtained

from aeroplanes and drones do not neces-

sarily contain this.

Yield data

Yield data is gathered by yield monitors in

combine harvesters. As the combine harvester

drives across the field and harvests, the yield

is continuously determined and captured in a

geographical database at global positioning

system (GPS) points. After the data has been

processed, yield maps of the fields are gener-

ated with the aid of geographical information

systems (GIS), and the areas where the crop

yield was higher and lower are clearly indi-

cated with, for example, different colours.

The lower yield areas, as obtained from the

GIS, are then investigated to determine the

possible causes of the reduced yield. Produc-

tion practices are then adjusted to eliminate

the yield-reducing factors in these areas so

that the whole field can yield according to

its potential.

If the combine harvester is equipped with

a yield monitor, it can be employed for

precision farming, and this is a meaningful

starting point.

However, the data must

be processed to meaningful interpretable

yield maps.

Growth indices

Remote sensing with the aid of satellite im-

ages, images from manned aeroplanes and

unmanned aeroplanes (drones) are increas-

ingly used to obtain digital images of fields.

These images must contain geographical

data to be used meaningfully in a GIS.

Images are usually taken in serial format

during the growing season. These are then

processed electronically in a GIS to produce,

among other things, growth indices (NDVI)

throughout the growing season. Areas with

differences in the relative crop growth are in-

dicated in different colours in this specific ap-

plication, so that areas where the crop growth

is lower can be identified. These lower-yielding

areas in the relevant field can be visited with

the aid of a GPS and studied to identify the

possible causes of poorer crop growth during

the season.

Growth indices are a relatively affordable but

also

easy starting point because the data is

processed by the supplier of the service to a

final product.

Chemical soil properties

The geographical spread of chemical soil

properties is done by way of grid sampling.

Soil samples are taken at GPS points, placed

in a grid pattern across the field. The soil sam-

ple for each GPS point is packaged separately

and analysed by a laboratory. The raw data is

fed into a GIS by the service provider and thus