The effect of white clover (Trifolium repens L.) and nitrogen fertilisation on biomass production, morphology, chemical composition and weed infestation of willow (Salix viminalis L.)

Abstract

The study was aimed at determining the effect of nitrogen fertilization and white clover on biomass yield weed infestation, morphology, and chemical composition of willow. A field experiment was established in 2013 at Wroclaw University of Environmental and Life sciences (Poland). The results showed that the number and dry mass of weeds per 1m 2 , the number of willow shoots and the fresh weight yield of willow were smaller where clover was sown. The plants were found to be higher after applying nitrogen fertilization. The dry mass yield and shoot diameter did not depend on the cultivation method. Nitrogen fertilization increased the content of ash, and in undersowing cultivation the willow stems had higher nitrogen content than in monoculture. On average, the phloem had 5.6 times higher crude ash content and 4.6 times higher nitrogen content than wood. The ratio of wood dry mass to phloem dry mass in undersowing cultivation and nitrogen fertilization was 3.97:1, and 3.91:1 for the control. On the basis of the conducted research, it can be concluded that in the first years after planting the undersowing growing of willow with white clover can be an alternative to plantations fertilized and non-fertilized with nitrogen.