Since ancient times, white lupin has been widespread in the Mediterranean region and in the Middle East due to its high tolerance for acidic soils and its soil-restoration abilities. It tolerates a soil acidity up to pH = 6.5, while
alkaline or organic soils are not suitable for growth. The soil must be well drained and loose because lupin is subject to root asphyxia. White lupin flourishes in the same climate zones as maize, although lupin, except at the beginning of the growing season, requires little water thanks to its long tap root.
Sowing In hotter climate zones, such as in Italy, sowing occurs following plowing in October–November in order to bury the stubble of the previous crop (often a cereal.) Due to its branched structure, lupin can adapt to different sowing densities, compensating for a lower density with a higher branch growth. In colder zones where lupin cannot survive the winter, white lupin is sowed in the spring, typically between March and April. The soil must be prepared as soon as possible after the last frost of the winter. The seedbed must be sufficiently fine, particularly in organic farming where mechanical weeding is done (so that harrowing the displacement of clods does not harm the plants). In regions where lupin is not indigenous, if it is cultivated for the first time in a soil or if the soil pH is higher than 6.5, lupin seeds must be inoculated with the nitrogen-fixing bacterium
Rhizobium lupini. Soil acidity is an important factor for nitrogen fixation.
Fertilisation Due to its symbiosis with nitrogen-fixing bacteria, white lupin does not need nitrogen fertilisation, though it requires about 40 kg/ha of P2O5 and 60 kg/ha of K2O. Due to its long tap root, white lupin can exploit phosphorus reserves in the soil. The crop rotation for white lupin ideally lasts at least four or five years, and lupin is often grown after a cereal crop. Lupin is a good preculture since it leaves about 50 kg/ha of nitrogen in the field.
Weed control Lupin does not compete well with weeds, particularly in the colder zones, because it only produces sufficient foliage to shade out weeds in late summer. Mechanical weeding is feasible, as is hoeing if the rows are wide enough. Chemical weeding is also used, by means of herbicides applied for other grain legumes.
Yield Depending on the climate zone of cultivation, pods ripen sometime between late June and late August. Seeds do not ripen all at once and are harvested when 90% of the pods are brown. To harvest with a combine harvester the ideal seed water content is 13-16%. Good yields are between 2 t/ha and 3.5 t/ha, although average yields are lower. == Diseases ==