ENERGY INVESTIGATIONS OF DIFFERENT INTENSIVE RAPE SEED ROTATIONS – A GERMAN CASE STUDY - Economics of Sustainable Energy in Agriculture - page 33

energy yield, whereas the integrated systems always had net energy outputs
which were at minimum 20 GJ lower than 'Conventional',
provided annual set aside was included (Figure 3.3 and Table 3.7).
Comparable values for the systems Int-a and Int-b taking in account only
the productive crops can be calculated from the givings in Table 3.5 and
Table 3.7. They show much smaller deviations from the reference systems.

Comparing single crops between the cropping systems, the net
energy yield of the integrated oil seed rape at Reinshof was almost the
same (Int) or higher than in the reference system (Int-a, Int-b resp.). In
Marienstein , the reference system remained the most favourable one in
both project periods (Table 3.7). The cereals in the integrated systems were
not competitive with their conventional counterparts, except oats which -
for comparison - must be seen as the integrated substitute for winter barley
in the reference system of the second project period. Consequentely, the
mean annual net energy yield in most cases remained below the reference
rotation, even if the annual set aside of the second project period was
excluded in the calculation of the integrated systems. Between the systems
'Integrated flexible' and 'Integrated without plough' only some slight