ENERGY INVESTIGATIONS OF DIFFERENT INTENSIVE RAPE SEED ROTATIONS – A GERMAN CASE STUDY - Economics of Sustainable Energy in Agriculture - page 29

Reinshof, -3.8 % Marienstein resp.; Table 3.4). That was affected mainly
by a lower amount and changes in the applied types of N-fertilisers
(introduction of ammonia sulphate) and by lower mean yields. The ranking
of the systems according to the area related energy use for mean years on
rotation level is found to be very stable over all investigated years (Figure
3.1). 'Integrated flexible' and 'Integrated without plough' were similar;
though in most years the latter had the lowest energy input on both sites.
Total area related energy input showed considerable differences
between locations and crops. As a tendency, it was higher at location
Marienstein (Table 3.5). Most crops had a higher demand of energy in the
reference systems than in the integrated systems compared. Table 3.5
shows a lower energy use per ha for 'Integrated without plough' than for
'Integrated flexible' for the majority of crops. Oil seed rape, winter wheat
and winter barley can be labelled as energy intensive crops, whereas oats
and field beans often need only little more than half of the energy input of
these crops (Table 3.5).
3.2 Energy intensity
Energy intensity of single crops (Table 3.6) was expressed as [MJ t dry
For investigations of energy intensity of whole crop rotations,
energy had to be aggregated as input per grain unit GU is a
German unit defined before the second world war for standardised
evaluation of different agricultural products, based on starch units, crude