The effect of mineral fertilizers and sheep manure on yields and quality of hay on the pasture mountain Stogovo in SR Macedonia [Yugoslavia, natural pastures]

The effect of mineral fertilizers and sheep manure, given in various doses of nutritive matters, on the yield, percentage of leguminosae, chemical composition and quality of hay was investigated, as well as soil properties before and after the investigation. The investigation was performed at the Mala Megdanica pasture, in the mountain of Stogovo (Yugoslavia). Complex NPK 10-30-20 fertilizer, with addition of "Kan", and sheep manure with the following composition: 1.20%N, 0.25%P2O5 and 0.50%K20 were used in the investigation. Sheep manure was distributed over the pasture surface only 1 year and its extended effect was found in the following years. The soil is limeless, rich in humus, total N and accessible potassium, especially in the surface layers. It is very poor in accessible phosphorus. Using varied doses and ratios of mineral fertilizers and sheep manure, it was found that the N80P60K60 dose gives the green mass surplus of 3,420 kg/ha and of 1.530 kg/ha a year. This combination increases the leguminosae percentage notably and changes the floral composition towards the Geranio-Poetum violaceae association, brings the raw protein content from 8.9% in the control to 11.3%. The P share in the hay is changed too, from 0.18% to 0.34% P2O5. Due to all this, according to DIG key, the hay quality improved from less good to very good. The given variant increased the accessible P share in the soil from the value below 1 mg to 5.8 mg in the 0-20 cm layer. The N80P60K40 variant is recommended for fertilization in the first 6-7 years, after that the fertilizer doses can be reduced to N40P40K40, or 300 kg/ha NPK 14-14-14. Sheep manure in the quantity of 20 t/ha gives good results used once in 4 years. It has an effect similar to the N40P60K40 dose and is recommended for the near-by and more level pastures.