Green biomass quality of perennial herbaceous crops depending on the species, type and level of fertilization

Abstract

The characteristics of biomass as renewable energy or bioindustry feedstock are very important from their final utilization point of view. This study aimed to evaluate the effects of fertilization on biomass characteristics and chemical composition during three-year field and laboratory trials. Two perennial herbaceous crops (Silphium perfoliatum L. and Helianthus salicifolius A. Dietr.) cultivated using different types (organic and mineral) and doses (0, 85, 170 kg ha–1 N) of fertilizers were investigated. The analyzed factors significantly influenced most of the investigated features of collected biomass. The application of fertilizers increased the fixed carbon and volatile matter content, higher heating value, chlorine, hemicellulose and cellulose content. The moisture content of green S. perfoliatum biomass harvested in September (75.8%) was 14.78% higher than in the case of H. salicifolius. The highest higher heating value (18.69 MJ kg–1 DM) and the lowest ash content (mean 4.72% DM) was obtained from H. salicifolius for the biomass fertilized at a dose of 170 kg ha–1 N with mineral fertilizer. Under mineral fertilization, the highest carbon content (47.88% DM) was obtained from H. salicifolius. However, the total nitrogen content in the S. perfoliatum biomass was the highest (1.41% DM) in 2019 for biomass treated with mineral fertilization in the dose of 170 kg ha–1 N. The highest content of hemicellulose (15.36% DM) was noted in H. salicifolius biomass, while cellulose and lignin contents were higher in S. perfoliatum (24.47% and 8.29% DM, respectively).