From the Polish patent description No 179311 a fertilizer consisting of brown coal, possibly of peat and mineral components is known. A brown coal content varies between 35-97% or alternatively high peat amounting up to 50%, biohumus up to 20%, chalk or gypsum up to 20%, acrylgel, possibly enveloped with a brown coal dust amounting for up to 10%, oil up to 2%, manure up to 20%, mineral fertilizers up to 20% and microelements up to 10%, while individual components are preferably enveloped with carbomethyl cellulose solution amounting for up to 0,5%.

A purpose of a solution according''to the invention is obtaining a product that maintains humidity for a substantial longer period of time.

From the Polish patent description No 179311, a process of manufacturing organic fertilizers is also known, in which brown coal is ground in machines that cut fibres crosswise, then the brown coal is screened and possibly undergoes gravitational or thermal drying at a temperature of 250° C and following components are added: high peat amounting up to 50%, biohumus up to 20%, acrylgel, possibly enveloped by a brown coal dust amounting for up to 10%, after which the mixture is homogenized and the whole is preferably enveloped with carbomethyl cellulose solution amounting for up to 2%, then manure amounting for up to 20% and mineral fertilizers amounting for up to 20% are added, including microelements amounting for up to 1 %, preferably enveloped previously with fat, preferably with oil amounting for up to 2% and/or chalk or gypsum amounting for up to 20%.

A purpose of a process according to the invention is preparation and proper use of waste components, so that they constitute a predominant part of a final product.

The essence of invention consists in that fertilizer includes-up to 60% of volume-a mineral wool with fibre length between 1 and 100 mm.

It is of advantage when an additional soil upgrade is brown coal.

An unexpected, advantageous result of the employment of the fertilizer according to the invention is a permanent improvement of soil characteristics, which at higher doses can rise by one valuation class.

The essence of the process according to the invention consists in that mineral wool is prepared in a form which has a fibre length varying between 1 and 100mm, after which it is mixed with other components of the fertilizer.

According to another characteristics of the invention, mixed components are composted for about a month.

An advantageous result of employing the process according to the invention is a very broad use of waste components, which constitute a predominant part of final product.

Exemplary composition of the fertilizer according to the invention includes 30% of mineral wool with fibre length varying from 1 to 100mm, 50% of dehydrated and composted sludge from municipal or zootechnical wastes and 20% of brown coal.

Exemplary employment of the process according to the invention consists in that a sludge from municipal or zootechnical wastes is dehydrated and composted, then screened. Mineral wool is formed in such way, that its fibre length varies between 1 and 100mm. Such prepared sludge from municipal or zootechnical wastes and mineral wool are mixed with brown coal at a ratio of 50% of dehydrated and composted sludge from municipal or zootechnical wastes and 20% of brown coal. Mixed components are composted for about a month.

The fertilizer according to the invention permits mixing it with other Selective acting fertilizers, which enhances its employment for very demanding crops.