The yield of autumn regrowth of grasses and the content of macronutrients are affected by environmental and agronomic factors as well as genetic traits of species and varieties. Biomass yield and the concentration of mineral elements determine their uptake by plants. The aim of this study was to evaluate dry matter yield as well as the content and uptake of N, P, K, Ca and Mg in the autumn regrowth of three varieties of red fescue in the first two production years depending on different sowing time and methods. This study was based on a strict field experiment conducted in 2004-2007, located in the Province of Kujawy and Pomorze (województwo kujawsko-pomorskie) (53°09˘N, 17°35˘E). The first factor was the time/method of sowing (spring: pure or with spring barley, and summer: in mid- and late July and in mid-August), while the second factor was the variety (chewings, slender creeping and strong creeping fescue cultivars). An average of 3.5 t ha–1 and 3.9 t ha–1 of regrowth of dry matter was obtained in the first and second production years, respectively. A delay of the sowing date until summer caused an increase in yield during the first production year in comparison with the spring sowing. In both years, the creeping variety gave the highest yield. The yield of the chewings variety was higher than that of the slender creeping one in the second production year. The concentration of N in the strong creeping variety was lower than that of the chewings one in the first year, and also in relation to the slender creeping variety in the second production year. The chewings and slender creeping varieties were characterized by a higher concentration of P than the strong creeping cultivar. The K and N uptake in the average regrowth yield from the first and second production years was the highest (106.3 kg ha–1 K and 62.7 kg N); the P and Ca uptake was low (12.5 and 11.3 kg ha–1) and that of Mg was the lowest (6.6 kg ha–1). A rise in the regrowth yield caused an increase in the N, P, K, Ca and Mg uptake in summer sowing crops compared with spring ones in the first year and a high uptake of these elements by the strong creeping variety in both production years.  In the first year, owing to the high N and P concentration, the uptake of these elements by the chewings and strong creeping fescue was similar. In the second year, the uptake of N, P, K, Ca by the slender creeping variety was the smallest due to a strong reduction in yield. In the first year, with no differences in the regrowth yield and K, Ca and Mg content, the uptake of these nutrients by the chewings and slender creeping varieties was similar.

18.3.2013