2.1.1 Total yield

Total yield of potato tubers was significantly modified by the examined factors and their interaction (table2). The highest yields of potato tubers were harvested from the objects

fertilized with a mixture of white clover with Italian ryegrass, white clover, and phacelia both plowed down in autumn, and left till spring in the form of mulch. Only after Italian ryegrass applying total yield of potato tubers was significantly lower than recorded on control object. Straw fertilization also significantly modified the yield of potato tubers. At the sub-block with straw, potato tuber yield was significantly lower than recorded at the sub-block without straw. An interaction has been noted, which shows that the highest yield of potato tubers were obtained from the object fertilized with a mixture of white clover with Italian ryegrass and white clover with straw, and the smallest from control object, without intercrop fertilization.