Lupins can be used to replace soya bean meal in dairy cow and lamb diets, therefore the potential for the crop in the UK and other Western European countries is substantial. Current UK production is around 7,000ha, mostly spring-sown, which produces about 17,500 tonnes. Average yields in the UK are in the region of 3.8-4.5t/ha.
There are over 300 different species of lupins, five of which are cultivated, but only three are suitable as a high protein feedstock. These are:
There is a very distinct difference between these three species of lupin and their feeding value. Blue lupins have a lower average crude protein value than either white or yellow lupins, with white lupins producing the highest Energy ME (15MJ/kg DM).
The agronomy of the different lupin types is relatively similar, with differences in sowing dates, as white lupins are often sown earlier (mid-March) than blue or yellow lupins, which are generally sown in April. As lupins are leguminous, they are capable of fixing large quantities of nitrogen from the atmosphere, however, it takes somewhere in the region of five weeks after sowing before the root nodules are capable of fixing nitrogen. In this time the seedling crop will require 25kg/ha Nitrogen, therefore this should be made available to the crop at the time of sowing.
Lupins will remove around 40-60kg/ha phosphate, 40-60kg/ha potash and 20-40kg/ha sulphur, depending on the yield. These nutrients, therefore, need to be applied, either in the seedbed or where the soil indices allow, later in the rotation. The crop may also suffer from manganese and magnesium deficiencies; therefore it is important that these nutrients are supplied where deficiencies may occur.