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2487497 
Journal Article 
Long-term effects on sward composition and animal performance of reducing fertilizer inputs to upland permanent pasture 
Yu, YW; Fraser, MD; Evans, JG 
2011 
Yes 
Grass and Forage Science
ISSN: 0142-5242
EISSN: 1365-2494 
66 
1 
138-151 
WOS:000310847600001 
This study investigated the long-term effects on sward composition and animal performance of applying different fertilizer regimes to upland permanent pasture. The experiment, which was carried out in 2008, was based on a set of replicated (n = 3) plots that had been established in 1990. The effects of applying (i) N, P, K and lime, (ii) P and K plus lime and (iii) lime only were compared with a treatment that received no nutrient applications. Using a put-and-take stocking system, the plots were grazed to a target sward surface height of 4 cm by ewes and lambs from April to early August and by ewes only from August to mid-October. The long-term reduction in nutrient inputs had led to decreases in the percentages of both sown and unsown grass species within the sward (P < 0.05), and an increase in the percentage of mosses and litter (P < 0 05), with a corresponding reduction in nutritional value. Although there were no statistically significant treatment-related differences in lamb growth rates, lower fertilizer inputs were associated with a marked decline in stock carrying capacity and associated overall productivity during both the pre- and post-weaning periods (P < 0 001). The findings highlight the challenges faced when attempting to reconcile production and environmental objectives in upland systems. 
fertilizer; extensification; sheep; botanical composition; nutritive value; liveweight gain