Fertilización nitrogenada y potásica en pradera mixtaII. Efecto sobre el nivel de microelementos

Abstract

The objective of the experiment was to evalúate the effect of nitrogen and potassium fertilisation on copper, iron, zinc and manganese content of the pasture growing in soil enriched by iron derived from anfiboles. The design of the experiment was split-plot with four replicates. Three doses of nitrogen were applied in the main plots (0 30+30 kg N ha1 , 60+60 kg N ha1) and three doses of potassium were applied in each sub-plot (0, 50+50 kg K20 ha1, 100+100 kg K20 ha1)- Inorganic fertilisers were applied at the beginning of the year and after the second cut. There were high iron levéis in the spring and very high levels in the autumn. The copper, iron, manganese and zinc content varied according with the time of the harvest. Iron and copper content were more affected by fertilisation than zinc and manganese but no clear tendency was found. Higher iron levéis did not provoke other mineral deficiency, however the levels of zinc and copper were not enough for feeding lambs and dairy and beef cattle