Wood ash and wastewater sludge recycling success in fast- growing deciduous tree – birch and alder plantations
¹Latvia State Forest Research Institute Silava, Riga Street 111 2169, Salaspils,Latvia; *Correspondence: firstname.lastname@example.org
Due to the increasing of wood as energy renewable resource in power and heat plantsthe amount of wood ash as waste will increase. Wood ash contains plant macronutrientelements P, K and different elements as micronutrients, only organic and nitrogen are missing.Wastewater sludge from small municipalities is usually clean, first-class material and contains alot of nitrogen and phosphorus. Wood ash can be a good fertiliser and a liming material not onlyfor acid organic soils, but also for mineral soils, but with a less significant effect on the treegrowth in first seasons than a nitrogen rich fertiliser wastewater sludge.The effects that wood ash and wastewater sludge have on the increment and survival of treeswere tested during the years 2011 and 2012 on loam and loamy soils at plantations of blackalder, birch and grey alder, and they were compared with the results collected in the previousresearch started in 2005. It was observed that wood ash in the first two seasons did notsignificantly increase the growth of silver birch, as wastewater sludge did, but it had a positiveeffect on the annual increment of grey alder. Fertilisation of the whole field decreased thesurvival of trees because of weed competition and different injuries.The aim of the study was to evaluate the growth of fast-growing deciduous trees seedlings asshort rotation crop under fertilisation of wood ash, and wastewater sludge on former agriculturalland.