Theme 22: Grazing Management
Description
The effects of grazing management on seed production, seed bank size and seedling emergence patterns of Trifolium repens cv. Zapicán (WC) and Lotus corniculatus cv. San Gabriel (BFT) oversown swards were evaluated. A complete randomized block design with 4 replicate blocks was used, in which 4 grazing strategies (grazing all year (SI), summer spelling for seed production (S2), winter rest plus summer spelling (S3) and autumn rest plus summer spelling (S4)), were combined with two defoliation severalties (4 and 10 cm height post-grazing residuals). Plots of 110 m2 were grazed monthly by sheep. Seed production, soil seed bank and seedling emergence were monitored from April 1998 to August 1999. In both species, summer spelling for seed production improved seed yield, especially in BFT. Severe defoliation (4 cm) reduced seed inputs drastically (46% in BFT and 64% in WC). 1000 seed weight was only affected by defoliation severity in WC (0.544 and 0.562 g for 4 and 10 cm height respectively). Potential seedling emergence, between June and December from soil seed bank, was 44 and 35% in BFT and WC, respectively. Seedling emergence of Lotus corniculatus increased under high seed production levels (S3), and also it was improved under intensive grazing during autumn and winter. There were no effects on Trifolium repens seedling emergence. Soil seed bank can preserve seedling recruitment rates in the short term, but maintenance of species balance will depend on seeding spelling management.
Citation
Ayalá, W.; Carámbula, M.; Risso, D. F.; Hodgson, J.; and Kemp, Peter D., "Effects of Management Strategies on Seed Production and Seedling Recruitment in Birdsfoot Trefoil-White Clover Mixtures" (2021). IGC Proceedings (1993-2023). 29.
https://uknowledge.uky.edu/igc/19/22/29
Included in
Effects of Management Strategies on Seed Production and Seedling Recruitment in Birdsfoot Trefoil-White Clover Mixtures
The effects of grazing management on seed production, seed bank size and seedling emergence patterns of Trifolium repens cv. Zapicán (WC) and Lotus corniculatus cv. San Gabriel (BFT) oversown swards were evaluated. A complete randomized block design with 4 replicate blocks was used, in which 4 grazing strategies (grazing all year (SI), summer spelling for seed production (S2), winter rest plus summer spelling (S3) and autumn rest plus summer spelling (S4)), were combined with two defoliation severalties (4 and 10 cm height post-grazing residuals). Plots of 110 m2 were grazed monthly by sheep. Seed production, soil seed bank and seedling emergence were monitored from April 1998 to August 1999. In both species, summer spelling for seed production improved seed yield, especially in BFT. Severe defoliation (4 cm) reduced seed inputs drastically (46% in BFT and 64% in WC). 1000 seed weight was only affected by defoliation severity in WC (0.544 and 0.562 g for 4 and 10 cm height respectively). Potential seedling emergence, between June and December from soil seed bank, was 44 and 35% in BFT and WC, respectively. Seedling emergence of Lotus corniculatus increased under high seed production levels (S3), and also it was improved under intensive grazing during autumn and winter. There were no effects on Trifolium repens seedling emergence. Soil seed bank can preserve seedling recruitment rates in the short term, but maintenance of species balance will depend on seeding spelling management.
