Some aspects of improvement of grassland production for grazing of sheep

Abstract

Grasslands represent significant natural resource with important role in economy and ecology of every country. Properly cultivated and utilized grasslands provide cheap and high quality food for sheep, which they easily transfer into milk and meat. However, extensive management has caused degradation of pasture areas. Improvement of production of forage plants on pastures is achieved by using melioration measures, primarily fertilization. Fertilization is important also from the aspect of increase of yield and quality of forage plants. The effect of application of fertilizer depends on the present plant species in the mixture. Application of nitrogen mineral fertilizers in mixtures reduces the nitrogen fixating abilities of leguminous species, which leads to the diminishing of their competitive abilities and favouring of the grass component in the mixture. Use of excessive quantities of N fertilizer in plants causes the accumulation of nitrates, as a unfavourable quality parameter in plant tissues, which can have harmful effect on animal health. Therefore, attention should be focused on application of N fertilizers, which should be harmonized with the plant requirements, so that used quantities are not excessive and harmful. Objective of this paper is to point out the significance of fertilization as one of the most important melioration measures.

Travnjaci su značajan prirodni resurs koji ima važnu ulogu u ekonomiji i ekologiji svake zemlje.Pravilno negovani i iskorištavani ,travnjaci obezbeđuju jeftinu i kvalitetnu hranu za ishranu ovaca koju one uspešno transformišu u mleko i meso. Međutim, ekstenzivno gazdovanje je uslovilo degradaciju pašnjačkih površina.Unapređenje proizvodnje krme na pašnjacima se postiže primenom meliorativnih mera, u prvom redu đubrenja. Đubrenje ima značajan uticaj na povećanje prinosa i kvaliteta krme. Efekat primene đubriva zavisi od prisutne biljne vrste u smeši. Primena azotnih mineralnih đubriva u smešama, smanjuje azotofiksatorne sposobnosti leguminoznih vrsta, što dovodi do slabljenja njihovih konkurentnih sposobnosti i favorizovanja travne komponente u smeši. Upotreba prevelikih količina N đubriva kod biljaka izaziva nagomilavanje nitrata, kao nepoželjnog parametra kvaliteta u biljnim tkivima, koji mogu da imaju štetno dejstvo na zdravstveno stanje životinja. Iz tih razloga treba pokloniti veliku pažnju primeni N đubriva, koja treba da bude u skladu sa potrebama biljaka, kako upotrebljene količine ne bi bile prevelike i štetne. Cilj ovog rada je bio da ukaže na značaj đubrenja kao jedne od najvažnijih meliorativnih mera.