Nitrogen application to dairy pasture - the effect of rate and timing of spring nitrogen applications on the concentration of pasture nutrients
Proceedings of the New Zealand Society of Animal Production, Volume 56, pp 276-279, Jan 1996
Article class: Conference Presentation
Subject Terms: Animal production/wastage, Carbohydrate, Diet/rations/food, Environment, Farm/farm management, Fertiliser, Grazing, Management, Minerals/elememts, Nutrition/metabolism, Pasture/crop, Protein, Seasonality/photoperiodNew Zealand Society of Animal Production
AbstractNitrogen (N) fertiliser was applied to ryegrass/white clover dairy pasture in late winter/early spring. Four rates of N (0, 20, 40, 80 kg N as urea) were applied to pregrazed and premown pasture with a residual herbage mass of 1000 kgDM/ha-1 (stubble height of 1.5 cm). Samples were collected from separate 2m² plots 2, 4, 6 and 8 weeks after N application to detect nutrient changes over time from N application and analysed for major nutrients (crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), soluble carbohydrate (SOLCHO) and dry matter (DM) %) as well as net herbage accumulation. Nitrogen was applied to separate areas on 15 August, 31 August, and 15 September to mimic the range of timing of N application used on commercial dairy farms. Nitrogen increased herbage CP, reduced ADF and NDF and reduced SOLCHO for 4-8 weeks after application. The effect of N on fibre and protein content of pasture was reversed 6-8 weeks after N application associated with increased pasture maturity, ground temperature and daylength. Increased crude protein and reduced fibre levels were more marked and longer lasting in early spring when conditions were cooler and daylength shorter, than in late spring. Consequences of the findings for dairy cow nutrition and pasture management are discussed briefly.
The whole of the literary matter of the Proceedings of the New Zealand Society of Animal Production is copyright New Zealand Society of Animal Production, Downloading this article signifies agreement with the terms and conditions of electronic access.