Biomass yield and chemical composition of Phalaris arundinacea L. using different rates of fermentation residue as fertiliser
¹ Latvia University of Agriculture, Institute of Agriculture, Zemkopibas inst. 7, Skriveri LV-5125, Latvia
² Latvia University of Agriculture, Faculty of Agriculture, Institute of Soil and Plant Sciences, Lielā iela 2, LV-3001 Jelgava, Latvia
³ Latvia State Forest Research Institute ‘Silava’, Rīgas iela 111, LV-2169 Salaspils, Latvia
Using biomass of various crops for bioenergy production is a common practice all over the world. Grasses, including reed canary grass (Phalaris arundinacea L.), as bioenergy crops have many advantages. Therefore it is important to look for the most effective technology to produce high biomass grass yields taking into consideration the quality parameters important for this purpose, and at the same time providing sustainable plant nutrient recycling schemes. The use of fermentation residue (FR) from biogas plants as fertiliser could be environmentally and economically cost-effective, as this by-product contain considerable amount of plant nutrients. However, there is little research on the efficiency of FR use for grassland. In our experiments we evaluated the effect of FR used at different rates (from N0 to N150 kg ha-1) and different treatment techniques (once/ twice/ or three times per season) on the productivity of RCG under two-cut and single-cut harvest regime. The data of three ley years (2012–2015) show that annual dry matter yields ranged from: 3.93–11.44 t ha-1 in two-cut and 5.89–13.94 t ha-1 in single-cut regime. The highest dry matter yield was obtained using FR at: 60 kg ha-1 N using the entire amount in a single application at the beginning of the season; 120 and 150 kg ha-1 N split for three applications. The chemical composition of reed canary grass biomass was mostly influenced by harvest regime: late harvest at single-cut regime ensured more appropriate sward quality for bioenergy production with a higher carbon and lower ash, nitrogen, potassium and phosphorus content.