Restoration of grassland sward is aimed mostly at improving their production and quality of obtained fodder. There are two legumes and three grasses species in deteriorated sward - preservation by means of reasonable management and fertilisation or with the aid of oversowing i.e. by introducing seeds of valuable grasses and legumes into existing sward. The oversowing experiments have been conducted on pasture in mountainous region site. Orchard grass appeared to be a species of highest production (28% of total) among grasses initially used and its rate has been increasing for consecutive years up to 50% of total in fifth year. The maximum proportion for white clover was 24% and for birdsfoot trefoil 18%. Both mineral fertilisation and oversowing appeared to improve production of pastures. Limited nitrogen fertilisation together with oversowing has resulted in its 25-33% rise. As regards undersowed pasture objects the best result was observed in the perennial ryegrass and white clover sward.
Seed yield components of white clover varieties /Alda, Astra, Owen, Radzikowska/ represented by 10 clones were Investigated in 2-year cycles of field experiments. Differentiation of clones within particular varieties with regard to weight and number of seed per head and 1000 seed weight was determined on the basis of Wricke's ecovalence coefficients. Also the share of genetic and environmental variance in the total variability of the traits under study was determined. It has been found that breeding work contributed to differentiation of yield components and ecovalence coefficients of the varieties tested and their representative clones. A lack of negative correlation between yield structure traits and ecovalence coefficients proved the possibility of improvement of the white clover seed yield stability.
Badania prowadzono na pastwiskach dla bydła, zlokalizowanych w dwóch siedliskach, na czarnej ziemi i glebie torfowo-murszowej. Udział roślin motylkowatych (Trifolium repens, Lotus corniculatus, Medicago lupulina i Medicago media) w mieszankach wynosił 50%. Pastwiska nawożono azotem w ilości 90 kg na glebie mineralnej i 45 kg-ha⁻¹ na glebie organicznej. Czynnikiem decydującym w istotny sposób o plonowaniu pastwisk był gatunek rośliny motylkowatej i jego trwałość w runi. W całym okresie badań najbardziej istotny pozytywny wpływ na produkcyjność pastwisk wywarła koniczyna biała. Znaczący plonotwórczy wpływ komonicy zwyczajnej zaznaczył się tylko na czarnej ziemi w pierwszych dwóch latach istnienia doświadczenia.