Higher yields of environmentally friendly potato require more organic fertilizers and irrigation. The most common organic fertilizer is cattle manure. The research goal is to study the effect of irrigation and high rates of cattle manure used in conditions of the southern forest-steppe of the Bashkortostan Republic on the yield and quality of potato tubers. The conducted study demonstrates increased potato tuber growth from 0.12 to 0.72 kg/plant and 0.30 to 0.79 kg/plant with a higher rate of cattle manure (120 t/ha) under rainfed and irrigation conditions, respectively. Cattle manure disposal is one of the most acute issues in terms of environmental conservation. It is a great concern in farming practice worldwide that requires the scientifically-proven use of farmyard manure. To get consistently high yields of crops and maintain soil fertility becomes possible when taking into account local agro-meteorological and soil conditions. The optimal rates of cattle manure for potatoes cultivated on leached chernozem in the southern forest-steppe of the Republic of Bashkortostan under irrigation and rainfed conditions were found. Potato growing at different rates of cattle manure application has been studied. There is an economic assessment of efficiency to apply different rates of manure.