Industrial model of agricultural intensification was oriented mainly towards higher level of yields and profit without taking in consideration the negative ecological and social consequences. The discrepancy in prices for nonrenewable sources of energy and their derivates, from one side, and relatively low prices for agricultural goods, from the other side, together with many other challenges faced by modern agriculture, have allowed to realize the unsustainability of the dominant concept of industrial intensification. Organic agriculture is one of the alternatives to conventional agriculture. Data from the long-term field experiment on ecological agriculture and permanent crops at Selectia Research Institute of Field Crops (Bălți, Republic of Moldova) are analyzed regarding the effect of crop rotations with and without mixture of perennial grasses and legumes, as well as the share of soil fertility in yield formation for different crop rotations and in permanent crops on different systems of fertilization (average for 2013-2022).