Lucrări Ştiinţifice – vol. 61(1)/2018, seria Agronomie THE QUALITY OF PRESERVED BIOMASS OF SOME POACEAE SPECIES UNDER THE CONDITIONS OF REPUBLIC OF MOLDOVA Victor ŢÎŢEI1 e-mail: [email protected] Abstract Energy is an essential ingredient of socio-environmental development and economic growth in the modern economy. Anaerobic digestion is an important way of making use of biomass resources and production of renewable energy, environmentally friendly and rapidly expanding in the latest years. Energy crops can be a suitable feedstock and if preserved they can be supplied to biogas plants continuously throughout the year. The aim of the current study was to evaluate the quality and biochemical methane production potential of preserved biomass (silage and haylage) prepared from Poaceae plants, 3-year-old perennial species Miscanthus giganteus and tall fescue Festuca arundinacea, winter cereal crops: rye Secale cereale and triticale Triticum secale. The silage and haylage prepared from these species mowed in June, by organoleptic characteristics (smell, colour and consistency) and biochemical indices (pH, content and correlation of organic acids, chemical composition of the dry matter), largely, met the standards. The chemical composition of the Miscanthus giganteus silage did not differ essentially compared to Triticum secale haylage. The biochemical methane production potential of Miscanthus giganteus silage made as a result of the first mowing in June reached 355 L/kg, Festuca arundinacea silage - 340 L/kg, Secale cereale haylage -333 L/kg, Triticum secale haylage - 358 L/kg organic matter, respectively. Key words: biochemical methane production potential, Festuca arundinacea, Miscanthus giganteus, Secale cereale, Triticum secale, preserved biomass Energy is an essential ingredient of socio- energy crop for biogas production, but its environmental development and economic growth cultivation, harvest and mineral fertilization in the modern economy. Rapid deployment of require high financial and fossil fuel inputs. The renewable energy and energy efficiency, and adverse climatic conditions, water deficiency in technological diversification of energy sources, soil, associated with high temperatures and strong would result in significant energy security and evapotranspiration from the last decades, had economic benefits. At the same time, there are serious consequences on the maize production. growing opportunities and demands for the use of Given the climatic conditions and the biomass to provide additional renewables, energy limited water resources in the Republic of for heat, power and fuel, pharmaceuticals and Moldova, it is necessary to reintroduce green chemical feedstocks. Anaerobic digestion is traditionally cultivated Poaceae species in crop an important way of making use of biomass rotation and to mobilize new and non-traditional resources, achieving a number of benefits through species, characterized by high tolerance and stable biogas technology, in the production of energy, the productivity, for growing on marginally productive protection of the environment and improvement of farms, restored degraded lands and denuded the ecology. For sustainable development of biogas community lands. Latterly much attention has been production is important to ensure a stable and focused on some winter cereals and perennial continuous supply of feedstock with suitable grasses with multiple-use. Rye, Secale cereale is quality and quantities. Storage conditions play a generally the most winter hardy of the cool-season vital role in maintaining biomass quality for annual grasses, is also the most productive on low various bioenergy opportunities. The well-known fertility, well-drained sandy soils, matures earlier techniques of biomass preservation include in the spring than most wheat varieties but ensiling and drying. generally produces more forage in the fall than Maize, Zea mays is the most popular wheat. Triticale, Triticum secale is a cross between Poaceae species used for livestock feeding and as wheat and rye. Triticale has an extensive fibrous 1 “Alexandru Ciubotaru” National Botanical Garden (Institute), Chişinău, Rep. of Moldova 177 Universitatea de Ştiinţe Agricole şi Medicină Veterinară Iaşi root system, can scavenge nitrogen very muffle furnace at 550°C. Nitrogen-free extractive effectively, and utilizes early spring moisture to substance (NFE) was mathematically appreciated, grow rapidly, tolerates drought and pests better as difference between organic matter values and than wheat, often produces more forage than many analytically assessed organic compounds. Organic varieties of wheat or rye. dry matter or volatile solids (VS), was calculated through differentiation, the crude ash being The tall fescue, Festuca arundinacea cool subtracted from dry matter. The content of neutral season perennial grass species, C3 photosynthetic detergent fibre, acid detergent fibre and acid pathway, native to Europe, common in the detergent lignin was evaluated using the near spontaneous flora of the Republic of Moldova, infrared spectroscopy (NIRS) technique PERTEN have a productivity of 50-65 t/ha of fresh mass or DA 7200 of the Research-Development Institute for 15-17 tons/ha of hay, implemented in different Grassland Brasov, Romania. The biochemical regions of the Earth, not only as a source of fodder, biogas potential (Yb) and methane potential (Ym) but also as feedstock for bioenergy production. were calculated according to the equations of Dandikas V. et al 2014, based on the chemical Promising perennial grasses, C4 photosynthetic pathway, natural hybrid Miscanthus compounds – acid detergent lignin (ADL) and hemicellulose (HC) values: giganteus, discovered in Japan in 1935, has very biogas potential Yb=727+0.25 HC-3.93 ADL high photosynthetic capacity, exceptionally methane potential Ym=371+0.13HC-2.00 ADL vigorous growth and remarkable adaptability to The carbon content of the substrates was different environments, make suitable for obtained from data on volatile solids, using an cultivation and distribution under a range of empirical equation reported by (Badger C.M. et. al, European and North American climatic conditions. 1979). Miscanthus giganteus is a high-yielding lignocellulosic crop. RESULTS AND DISCUSSIONS The aim of the current study was to evaluate the quality and biochemical methane production It is known that the ratio of stems to leaves potential of preserved biomass (silage and haylage) influences the chemical composition of biomass prepared from Poaceae plants: Miscanthus intended for livestock feeding or for use as a giganteus, Festuca arundinacea, Secale cereale means of obtaining various industrial products. and Triticum secale. The results regarding some bio-morphological characteristics of the studied Poaceae species and MATERIAL AND METHOD the structure of the harvested biomass are presented in table 1. The studied species differed The Poaceae species, 3-year-old perennial in the growth and development rate, which affected species Miscanthus giganteus and tall fescue the accumulation of aerial biomass and its Festuca arundinacea, winter cereal crops: rye structure. At the time of harvesting, mid-June, Secale cereale and triticale Triticum secale, served Miscanthus giganteus plants were in the intense as subjects of the research, maize Zea mays - stem elongation stage, the other species – in the control. generative period - milk-ripe stage. Plant height The green mass was harvested manually. varied from 137 cm (Festuca arundinacea) to The samples were collected in middle of June 195 cm (Secale cereale), stem thickness 9-12 mm Miscanthus giganteus in stem elongation period, Festuca arundinacea, Secale cereale and Triticum in Miscanthus giganteus and 1-3 mm in the other secale in milk ripe. The control Zea mays was species. The biomass of Miscanthus giganteus had harvest in kernel milk-wax stage in middle of the largest proportion of leaves (51.8 %), followed August. The Miscanthus giganteus, Festuca by Triticum secale (37.7 %), but Secale cereale arundinacea and Zea mays silage was prepared contained the largest proportion of stems (61.2 %). from harvested green mass, but Secale cereale The species Festuca arundinacea and Triticum and Triticum secale haylage was prepared from secale had the highest content of dry matter in the wilted green mass (32-hour wilting time after freshly harvested biomass: 41.1 % and 37.1 %, cuting), shredded and compressed in well-sealed respectively. During the research carried out in glass containers. After 30 days, the containers USA, it was found that, in the milk stage of grain were opened, the organoleptic characteristics were analyzed and the biochemical composition of the fill, the rye fresh mass contained 7.1 % leaves, silage and haylage were evaluated in accordance 70.0 % stems and 22.9 % spikes (Beck P., Jennings with standard laboratory procedures for forage J., 2014). In Canada, the natural fodder of triticale quality analysis. Dry matter or total solid (TS) contained 24.0 % leaves, 35.0 % stems and 40.8 % content was detected by drying samples up to spikes (Khorasani G. R. et al, 1997). constant weight at 105 °C. Crude protein – by The preserved biomass of the investigated Kjeldahl method; crude fat – by Soxhlet method, Poaceae species had different smell, colour and crude cellulose – by Van Soest method; ash – in 178 Lucrări Ştiinţifice – vol. 61(1)/2018, seria Agronomie dry matter content. Miscanthus giganteus silage assessment, it was found that the colour of Festuca