Rasma Platace

Influence of nitrogen fertilizer on grass biomass yield and amount of energy gained per area unit

Sustainability of biomass is characterized by its composition, physical properties and other qualitative parameters such as the amount of area required for gaining a unit of biomass energy – GJ·ha·year –, which strongly depends on the productivity (i.e., yields per area unit) of the managed ecosystem. Perennial grasses are essential for the agricultural production sector in Latvia. The nature and extent of winter damage on grasslands highly dependupon the climatic conditions, moreover, it influences both persistency and the yield. Scientists have found that plant biomass is one of the best sources that may be used for the production of solid biofuels. The field trials were carried out in sod calcareous soils in 2011–2014. The following grass cultivars were used: reed canary grass (Phalaris arundinaceae (L.) Raush.), festulolium (×Festulolium Asch. & Graebn.), timothy (Phleum pratense L.), meadow fescue (Festuca pratensis) Huds.), and tall fescue (Festuca arundinaceae Schreb.). Fertilizers applied: main fertilizer (F) – P80K120 kg·ha; and six additional nitrogen fertilizers: F + 30, F + 60, F + 90, F + 120, F + 150, and F + 180 kg·ha N. In our study, the highest energy yield per 1 ha was obtained from tall fescue (119.8 GJ·ha) and timothy (145.3 GJ·ha), when 180 kg·ha of nitrogen fertilizer were applied, which was 54 % and 73 % more, respectively, compared to the unfertilized plots.