The agricultural value of an extensive, alternativly used grassland with three seed densities (500 seed m-2, 1000 seed m-2 and 1500 seed m-2) and at two sowing times was examined in an established grassland experiment with herbs on sandy brown forest soil in Gödöllő in the spring and autumn of 2002.
The results showed that treatment No. 3 (=1500 seed m-2) had the highest agricultural value. It can be concluded that the highest seed norm resulted in the highest grass cover. Through the estimated agricultural value, we have also proved that the grass established in autumn grows more vigorously than the dicotyledonous species. This follows from the biological characteristics of the two plant groups. The grasses are tolerant towards cold and perennial species, while most of the dicotyledonous are annual and prefer milder conditions.
Grassland areas with the same ecological basis differ greatly as far as their plant composition is concerned, depending on seed density. In addition, the plant composition changes continusly according to sowing time.