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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Publications at this Location » Publication #412912
Research Project: Improving Sustainability of Dairy and Forage Production Systems for the Upper Midwest

Location: Environmentally Integrated Dairy Management Research

Title: Effect of nitrogen fertilization on yield and nutritive value of fall-stockpiled tall fescue, meadow fescue, or orchardgrass

Author
item Akins, Matthew
item CAVADINI, JASON - University Of Wisconsin
item WELLS, KATE - University Of Wisconsin
item PIZARRO, DANTE - University Of Wisconsin
item WATTIAUX, MICHEL - University Of Wisconsin
item PICASSO, VALENTIN - University Of Wisconsin

Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2024
Publication Date: 6/16/2024
Citation: Akins, M.S., Cavadini, J., Wells, K., Pizarro, D., Wattiaux, M., Picasso, V. 2024. Effect of nitrogen fertilization on yield and nutritive value of fall-stockpiled tall fescue, meadow fescue, or orchardgrass. American Dairy Science Association Abstracts. 107(Suppl. 1): 366.

Interpretive Summary:

Technical Abstract: Extending the grazing season using stockpiled forages can reduce costs, but minimal information on N fertilizer rates for stockpiled forage is available. This study evaluated stockpiled forage yield and nutritive value of three grass species (tall fescue, TF; meadow fescue, MF; and orchardgrass, OG) when fertilized with 0, 34, 67, or 100 kg N/ha as urea and harvested at three times in a split-split-plot design. The study was replicated two years (2020, 2021) with four replicate blocks. Urea was applied in early Aug after a forage harvest, then forage was allowed to accumulate until harvested in fall (mid-Oct, early Nov, late Nov). Data were analyzed with Proc Mixed of SAS. Yield was affected by a species x N-rate interaction (P<0.01) with N increasing yield for all species, however TF was more responsive. Harvests in mid-Oct (4077 kg DM/ha) or early Nov (4255 kg DM/ha) had similar yield, but by late Nov (3531 kg DM/ha) yield decreased. Forage CP increased (P<0.01) slightly with N (9.6, 9.5, 9.8, and 10.2% CP for 0, 34, 67, and 100 kg N/ha, respectively), but was more affected by species with MF (12.7%) having higher CP (P<0.01) than TF (7.8%) or OG (8.7%). Grass species had large effect on NDF (54.8, 58.5, and 59.7% NDF for MF, TF, and OG, respectively; P<0.01) while N fertilizer only slightly increased NDF (P<0.01). In-vitro 48-h NDFD was unaffected by N-rate (P=0.30), but species had a greater effect (58.9, 63.0, and 65.9% NDFD for MF, OG, and TF, respectively; P<0.01). Also, TF (11.7%) had greater (P<0.01) water-soluble carbohydrates (WSC) than MF (8.8%) and OG (9.3%), while harvest date had a large effect (P<0.01) on WSC with higher values in early and late Nov due to frosts and plant hardening. Overall, N fertilizer is key to higher stockpiled forage yield but had limited effects on nutritive value.