Biomass yield and quality of barley forage prior to ensiling as affected by fertilizer rate and harvest date

LAGRANGE, SEBASTIAN; ARELOVICH, HUGO MARIO; FRACHE, FRANCO; BRAVO, RODRIGO D.; MARTÍNEZ, MARCELA FERNANDA; AMELA, MARÍA INÉS

Indianapolis

Congreso; ADSA-ASAS-CSAS Joint Annual Meeting 2013; 2013

ADSA-ASAS-CSAS

Planting barley (Hordeum vulgare L.) for the malt industry is growing in semiarid Argentina. However, barley grazing, hay production and more recently silage making is also practiced. A reduction in quality is expected after ensiling process, which could be attenuated by harvesting material of higher nutritional value. The objective was to evaluate forage yield and nutritional quality of barley (?Josefina INTA?, bred for malt attributes) as affected by N fertilizer rates (NFR) at 2 grain maturity stages milky (M1) and dough (M2). Urea was applied at tillering at the rates of 0, 50, 100 kg N/ha upon 1.4 by 5 m plots allotted to a complete randomized block design. Furrows were 20 cm apart with a plant density 220 /m2. Annual precipitation was 711.4 mm with 314.6 mm falling within the crop development period. Dry matter (DM) yield and forage content, crude protein (CP), neutral and acid detergent fiber (NDF, ADF), lignin (ADL) soluble non-structural carbohydrates (SNEC), in vitro DM digestibility (IVDMD) and metabolizable energy (ME) were determined. No interaction NFR by maturity stage was found for any variables. For DM yield no differences were found between NFR. Fertilized vs. nonfertilized crops produced 900 and 2000 kg DM/ha more for M1 and M2 respectively (P < 0.01). Overall quality parameters were higher for M1 harvest; however, within M2, NFR100 substantially increased CP (P < 0.01) with a nonsignificant trend observed for increased IVDMD. A larger DM volume with acceptable quality at NFR100 could be obtained at M2; however, the best ensiling conditions (lower DM content) and nutritive value were found harvesting at M1.