Fertilization, irrigation and pasture sown to improve herbage production and quality in Nothofagus antarctica silvopastoral systems in southern Patagonia

Abstract

Nothofaus antarctica forest extends from 46 to 56º SL been used as silvopastoral systems (SSP). Several studies have characterized understory of N. antarctica SSP. However, other practices like pasture sawn, irrigation and fertilization, to improve understory yield, remains undocumented. The aim of this work was to compare dry matter (DM) production and quality of natural understory vs. implanted pastures under different water and nutrient conditions. An experiment with fifteen plots of 6x 6 m where randomly established in a split-split plot design with specie as the main factor, water as the sub-plot factor and fertilizer application level as sub-sub-plot factor. The species evaluated were: Dactylis glomerata, Bromus catharticus, Trifolium pratense, T. repens and natural understory. Total dry matter (DM) production, leaf N concentration and digestibility were measured after one and two years of experiment establishment. Significant differences were found in DM according to specie, water and fertilization treatment. The highest DM production was for D. glomerata with irrigation and 100 kg N ha^− 1 (6347 kg DM ha^− 1), followed by natural understory with irrigation and 200 kg N ha^− 1 and T. pratense with irrigation after the first year. In contrast, after two years, significant differences were found only for specie and fertilizer treatments where the highest yield corresponded to T. pratense pasture. For quality T. repens had the highest digestibility values. This study showed that pure pastures of D. glomerata accompanied by N fertilization or T. pratense, are viable options to increase forage yield and quality in N. antarctica SSP.