In vitro digestibility (IVD) and yield of digestible dry matter (DDM) was determined on four forage species; Saratoga bromegrass (Bromus inermis L.), Frode orchardgrass (Dactylis glomerata L.), Climax timothy (Phleum pratense L.) and DuPuits alfalfa (Medicago sativa L.) grown as single species over a 2-year period. Nitrogen and potassium fertilizer in various combinations and rates were applied to these forage species. Two cuttings per season of the various species were harvested. Fertilization with nitrogen and potassium did not affect IVD of grasses at any of the rates applied. The IVD of alfalfa was increased by potassium fertilization, while DDM yield was increased by both nitrogen and potassium fertilization.Each forage species was also harvested at 4-day intervals throughout the season to determine effect of advancing maturity on digestibility. The IVD of the first harvest of forage early in June averaged 77% for the four species, but by late July it had dropped to 58%. Of the four species tested, t...

In vitro digestibility of forage species as affected by fertilizer application, stage of development and harvest dates

The effects of over 25 yr of levels of applied N, P and K on forage DM yield, crude protein content, in vitro digestibility (IVD), botanical composition and persistence of a timothy (Phleum pratense L.) sward were assessed in a long-term field experiment on an acidic Riverbank L. Ammonium nitrate (0, 90, 180, 270 kg N ha−1), superphosphate (0, 15, 29, 44 kg P ha−1) and muriate of potash (0, 47, 94, 141 kg K ha−1) were applied annually in all possible combinations to a timothy sward since 1960. In the first 3 yr of the experiment, only N and K were required for maximum yield and persistence of timothy. The requirement for applied P, however, increased with time; in the last 3 yr (1985–1987) of the trial, the highest level of applied P resulted in profitable forage DM yield increases. After 25 yr, the productivity of the timothy sward was dependent upon a balanced application of all three macronutrients; absence of any one nutrient resulted in little or no response to applications of the other nutrients. Th...

Effects of 25 years of n, p and k fertilization on yield, persistence and nutritive value of a timothy sward

The aim of the present study was to investigate the influence of cutting frequency, harvest season and nitrogen fertilization on yield and floristic composition of the herbage harvested from a mountain meadow The meadow was divided into 22 plots, each receiving a different N P K fertilization treatment The study lasted seven years, and during the first three years (1985-1987) each plot was harvested twice per year (June and September) according to a traditional harvest system, whereas in the years 1989-1991 each plot was harvested three times per year (spring, summer and autumn) following a more intensive harvest system Nitrogen fertilizer favoured the development of the grasses in spring, thus reducing the proportion of legumes in the two cut harvest system, whereas grasses reached an advanced stage of maturity before the first cut in late June However, the three cut harvest system entailed an earlier first cut in spring As a result, the production of legume biomass was significantly increased both in the first cut and in the subsequent regrowths No significant response in total herbage production to the N fertilizer was observed in the more intensive harvest system Therefore, the three cut harvest system without nitrogen fertilization seemed to be the most suitable practice for the management of these botanically-complex mountain meadows These results may contribute to design fertilization and management practices of mountain hay meadows to optimize their productivity and sustainability

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Influence of harvest season, cutting frequency and nitrogen fertilization of mountain meadows on yield, floristic composition and protein content of herbage

Satisfying the Nutritional Requirements of Grass-Legume Mixtures

The digestibility and productivity of selected herbage varieties.

In 2 experiments nitrogenous fertilizer was applied at 3 levels (0, 46 and 92 lb N/ac) to a permanent pasture and a ryegrass/clover ley and the swards were harvested before ear emergence and conserved as either artificially dried grass or tetrapod hay. Apparent dry matter digestibility and voluntary food intake of the conserved herbages were measured with sheep.



N caused a small but significant depression in apparent DM digestibility but did not affect voluntary food intake. It increased yields of DM and digestible DM significantly.



The DM digestibility and voluntary food intake of hay were always significantly lower than those of the corresponding dried grass. Voluntary food intake of all fodders was directly related to herbage digestibility and inversely related to herbage crude fibre content.

R. K. Wilson

Papers

Effects of nitrogen fertilization of mixed swards on herbage yield, dry matter digestibility and voluntary food intake of the conserved herbages