Hemp is a good substitute for cereals in the crop rotation. It has lower fertiliser requirements. The guideline is 70 - 110 units of active nitrogen[1] per hectare, of which more than 80% is animal manure. In comparison, wheat might require up to 250 kg/ha. The lower fertilization requirements for hemp leaves room to use fertilizer for other crops.
Fibre hemp grows on average 4 cm per day, faster than bad weeds, which are therefore suppressed naturally.
There are currently no known diseases that require plant protection products (herbicides) for both organic and conventional fibre hemp cultivation.
In addition, hemp has a suppressive effect on a number of soil fungi such as Verticillium dahliae and the maize root-knot nematode (Meloidogyne chitwoodi). Hemp also suppresses the northern root-knot nematode (Meloidogyne hapla); complete resistance to this nematode has even been found for some varieties. As a result, subsequent crops are also less affected by these fungi and nematodes.
Added up, hemp requires less labour than other crops such as cereals, beets and potatoes, while a nice yield can be obtained just as well (§2.6).
[1] 1 Unit of nitrogen corresponds to 1 kg of the element ‘nitrogen’ (N) in a fertilizer which is composed of nitrogen compounds.