Effects of harvest period, nitrogen fertilization and mycorrhizal fungus inoculation on triticale (×Triticosecale Wittmack) forage yield and quality

The practice of grazing winter cereals before heading and subsequently harvesting the forage is common in some countries. Triticale (× Triticosecale Wittmack) is particularly interesting due to its nutritional characteristics, and forage yield and quality are strongly influenced by agronomic techniques. The effect of two modes of utilization (cut at heading stage and cut during winter grazing simulation with regrowth cut at heading stage), three nitrogen (N) fertilization levels [0 and 100kgha−1 split in two phases; and 100kgha−1 before sowing, using a fertilizer with 3,4-dimethylpyrazole phosphate (DMPP) as a nitrification inhibitor (NI)] and mycorrhizal fungus inoculation (mixed inoculation of Glomus intraradices and Glomus moseae) on forage yield and quality, protein fractions and in vitro digestibility of triticale was determined in southern Italy. Mode of utilization and fertilization affected significantly forage yield and quality, while mycorrhizal fungus inoculation influenced positively some quality parameters. Cutting at heading stage of triticale led to high dry matter (DM) production compared to the winter cut simulating grazing, but no differences in protein yield (PY). N fertilization increased total DM and PYs, but no differences were reported among the application modalities of N fertilizers. Triticale protein fractions and protein and fiber digestibility were improved by N fertilization. Mycorrhizal fungus inoculation positively influenced forage quality at heading stage, which resulted in more digestible fiber and protein. As a result, when triticale was grown under Mediterranean conditions, mode of utilization and N fertilization resulted in greater forage yield and quality, while mycorrhizal fungus inoculation influenced positively forage nutritional quality parameters.