ENERĢĒTISKO AUGU PLANTĀCIJĀ AUDZĒTO DAUDZGADĪGO ZĀLAUGU MĒSLOŠANAS EFEKTIVITĀTE.

Recently the demand for biomass for bioenergy and fiber in many countries has been changing the traditional utilization of grasses for forage. Grasslands compared to other crops for agro-fuel production can be produced on marginal agricultural lands, since they do not require high amounts of fertilisers and pesticides thus having a better impact on biodiversity. Agroforestry is a perspective way of biomass production which combines simultaneous growing of woody plants with agricultural crops on the same area for different purposes. At the same time successful management of waste product enlarged amount is very important. Field trials were established in 2011 at the Research Institute of Agriculture at Skriveri in collaboration with the Latvia State Forest Research Institute "Silava" with the aim of studying various fast-growing deciduous trees species without and with perennial grasses between the trees, as well as herbaceous energy crops. The objective of this research was to evaluate the grass biomass and seed yield of Phalaris arundinacea L. (RCG), F.arundinacea x L.multiflorum (festulolium) and Galega orientalis Lam. using different bio-energy and municipal waste products as fertilisers: sewage sludge, biogas digestate and wood ash. The trial results showed a significant dry matter and seed yield dependence on used grass species and fertiliser. The greatest average dry matter yield increase for RCG and festulolium was provided using mineral fertilisers (3.92 t ha-1 and 3.81 t ha-1 respectively) and wood ash combined with mineral fertilisers (3.00 t ha-1 and 3.63 t ha-1 respectively). For galega the greatest average dry matter yield increase was obtained by using sewage sludge (1.41 t ha-1) and digestate (1.34 t ha-1.). [ABSTRACT FROM AUTHOR]