The experiment was carried out in the years 2009-2010 in organic farm of Agricultural Experimental Station Grabów (mazowieckie Voivodeship), by crossed subblock method. Dose of natural fertilization (20 and 40 t composted manure per 1 ha) was the first factor and the second factor - cultivation method: A - control object (without weed control), B - brush weeder (three times during the vegetation season), C - weeding hoe (three times during the vegetation season), D - brush weeder (two times during the vegetation season) and hiller. In the year with limited amount of rainfall in July and significantly more in August (2010), using of differentiated mechanical treatments for weed control had little influence on sorghum yielding. However, in the year with more amount of rainfall in July and significantly less in August (2011), the highest yields had been noted on the objects, where brush weeder (three times during the vegetation season) and brush weeder (two times during the season) and hiller on plants (with their 30 cm height) were used. The abandonment of mechanical cultivation independent on organic fertilization dose caused decreasing of dry matter sorghum yields from 17% to 40% in comparison to objects, where mechanic cultivation were used. Under conditions of limited amount of rainfall in July, yielding of sorghum fertilized by dose of 20 t per 1 ha were similar to those fertilized by dose of 40 t per 1 ha. However in the year with more amount of rainfall, higher dose of organic fertilization had favorable influence on yielding of dry matter, independently on treated mechanical cultivation. Content of dry matter in whole sorghum plants was little differentiated both organic fertilization and cultivation method. The less of dry matter content in plants fertilized by higher dose of compost independently on cultivation method had been noted in 2010 year.