Influence of fertilisation type and harvest date on lignin content and structural carbohydrates in meadow plants

The nutritional value of green forage is a result of various pratotechnical practices, including fertilisation and harvest timing. Additionally, individual plant species present in natural grasslands may respond differently to those practices. The study aimed to investigate the effect of fertilisation type (farm yard manure (FYM) and NPK fertilisation) and the timing of the first regrowth harvest of meadow sward (ten harvest dates) on the lignin and structural carbohydrates of three dicotyledonous meadow plants: Taraxacum officinale F.H. Wigg., Achillea millefolium L. and Lotus corniculatus L. Plant material was harvested from 28 Apr until 26 Jun at 7-day intervals and analysed for cellulose (CL), hemicellulose (HCL), and acid detergent lignin (ADL). The levels of neutral detergent fibre (NDF), acid detergent fibre (ADF), and ADL were measured using near-infrared spectroscopy (NIRS) with a NIRFlex N-500 device. Cellulose was calculated as the difference between ADF and ADL, while HCL was calculated by subtracting ADF from NDF. T. officinale had the lowest HCL (average 65.5 g∙kg−1 DM) and ADL content (47.1 g∙kg−1 DM) while A. millefolium had the highest CL content (266.5 g∙kg−1 DM) and ADL (52.3 g∙kg−1 DM). In contrast, L. corniculatus accumulated the highest HCL (104.5 g∙kg−1 DM) and the lowest CL content (246.1 g∙kg−1 DM). An increase in all studied parameters content was observed with later harvest dates. On average, plants fertilised with FYM contained lower amounts of structural carbohydrates and ADL compared to those fertilised with NPK.