摘要：The paper presents a general guide for agricultural specialists who want to understand the basic principles of grassland renovation in the specific conditions of Romanian nemoral regions. Requirements of higher herbage yields than the potential productivity of natural grasslands situated in the nemoral areas of Romania have imposed the integration of temporary artificial grasslands as intensive forage systems in order to replace degraded or inefficient permanent pastures. Considering the vast regions occupied by natural hayfields in Romania (~1.4 mil. ha) from which the favorable area for potential red clover integration reaches 20-25%, it becomes important to investigate and identify an adequate substituting solution for the initial phytocenosis of the degraded permanent grasslands only in areas where the replacement of natural biodiversity is justified economically and ecologically. Improving the productivity of inefficient grasslands relies on an intensive crop system based on mixtures (legume - grass species), whose resource consumption particularities are physiologically, temporally, and morphologically complementary. Elaboration of mixed crop technologies tested in field experiments has proved the superiority of the legume-grass mixtures concerning the fodd er quality and quantity, when compared to sole-cropped of the component species or to grasslands with low pastoral value. However, yield constancy was not always obtained due to seasonal fluctuations and incorrect management practices. Because of demonstrated efficiencies of using mixtures, it was hypothesized that the adequate intensive mixtures for the hilly areas of Romania consist in red clover-ryegrass, red clover-timothy, or red clover-meadow fescue in correlation with altitude. The choice is a result of their complementary characteristics and adaptability (similar growth rate, height and development, cutting frequency, cultivar tardiness etc.).
