The method of tillage is one of the major factors determining the yield of root plants. Today we witness the degradation of soil on large cultivated lands. It is a result i.a. of more frequent tillage practices, and the omission of cover crops. The destruction of aggregate structures of the soil and the lowering of its organic matter content cause that conditions for growth and yields of the main crops are becoming worse. Field experiments were conducted in the years 2006–2008 on grey-brown podzolic soil with impermanent structure. The test plant was the rooted chicory (Cichorium intybus var. sativum Bisch.) of the ‘Polanowicka’ cultivar. This species has an important economical meaning, providing precious raw materials for inulin production. The experiments included: two kinds of pre-sowing tillage: a) a complex of pre-sowing tillage and sowing of cover crops (2^nd decade of August) and pre-winter ploughing and mixing the green mass with soil, b) a complex of pre-sowing tillage and sowing of cover crops (2^nd decade of August), leave them in the field during the winter and ploughing the plant mass in spring; two types of plant growing: in ridges or in flat soil; three cover crops: common vetch, tansy phacelia and oats. Beneficial influence of mulching the soil with tansy phacelia on the total chicory root yield, compared with unmulched plots was observed. The highest content of inulin was found in chicory roots collected from plots mulched with common vetch. It was significantly higher than its content in roots coming from the plots mulched with oats. When the productivity of inulin per unit of area is taken into account, the most beneficial tillage combination was the tillage of chicory in ridges, after spring ploughing, mixing the mulch of common vetch with the soil. Both the cultivation of the plant in ridges and ploughed vetch affected the yield significantly. The factors of the experiment had no significant influence on the content of dry matter and protein in the roots of chicory.

79-89