Sulphur in balanced karst pasture nutrition | Žveplo in uravnotežena oskrba ruše kraškega pašnika

anglais. In the work described in this paper, the effects of sulphur (S) fertilizers in combinations with nitrogen (NP) and phosphorus (P) fertilizers on herbage production were investigated. Results from the first three years of experiment carried are reported. Field experiment was carried out at mountain sheep pasture Vremščica. Sulphur was added at a rate of 60 kg ha-1. Same was for nitrogen. Phosphorus was applied at 90 kg ha–1 each year. As a result of more balanced supply of nutrients to plants, and the sheep grazing, the similar herbage mass was obtained few days earlier during each consecutive year. Most efficient on average was the combined application of NPS which gave 24 % higher yield of herbage than control treatment. Statistically significant differences were found (P=0.05) further for NP, NS and NPK treatments too. Clover content showed a trend for a slight decline on treatments where N was applied. This small decrease in clover content was probably a result of the shading of clovers by grasses. Amount of herbage utilised during two rotations was 3.5 t ha –1 DM for NPS treatment, and this was for 67 % higher from what was achieved on control treatment.

slovène. Proučevan je bil vpliv gnojenja z žveplom (S) v kombinaciji z dušikom (N) in fosforjem (P) na pridelek zelinja kraškega pašnika. Prikazani so rezultati dela prvih treh let. Poljski poskus je bil izveden na planini Vremščica, na pašniku za ovce. Z žveplom je bilo gnojeno 60 kg ha-1. Enako je bilo z dušikom. Fosfor je bil dan vsako leto v odmerku 90 kg ha –1. Učinek uporabljenih gnojil in pašne rabe ruše se je pokazal v ranejšem pričetku rasti ruše vsako naslednje leto. V povprečju je bila najbolj učinkovita uporaba NPS gnojil skupaj, ki je dala za 24 % večjo maso razpoložljivega zelinja v primerjavi z negnojenim postopkom. Statistično značilne razlike (P=0,05) so bile ugotovljene tudi za postopke gnojenja NP, NS in NPK. Delež bele detelje se je nekoliko zmanjšal na postopkih, kjer je bil uporabljen dušik. To zmanjšanje je bilo verjetno posledica senčenja detelje zaradi višje rastočih trav. Skupna masa zelinja, ki so ga ovce izkoristile v dveh obhodih je znašala na postopku NPS 3,5 t ha–1 SS, kar je za 67 % več kot je bilo ugotovljeno za kontrolni postopek.