Phosphorus (P) is an essential element for grassland productivity, but P fertilizers are mined from finite resources of phosphate rock. As a result, there is growing interest in increasing the efficiency of P fertilizer !use in agriculture to ensure the future sustainability of food production. This project was designed to increase our knowledge on the behaviour of, and requirements of P in grassland soils. The results which include data from a long-term field experiment showed that a sustained annual application of 15 kg P ha-1 y(l was required for maximum herbage yield whilst seasonal trends indicated that P concentration in herbage was lowest during the summer months. Results from a field experiment which examined the effects of N, P and lime on two sites with contrasting soil fertility levels found a comparable response to nitrogen and P on the herbage yield while soil P levels had a strong influence on herbage P concentration. A soil incubation experiment carried out on a range of different Irish soils showed that lime plays an important role in increasing the availability of soil P and fertilizer P. In the same range of soils the examination of soil organic P was investigated and the results highlight the variation that exists in organic P species in Irish soils. Overall the results from these experiments suggests that as the future availability of P fertilizer becomes uncertain, a greater emphasis on soil specific fertilizer P guidelines will be required to maximise P efficiency in grasslands. This project will underpin the rationale and provide initial results which will aid the future implementation of a more soil specific P fertilizer guidelines in Ireland. Furthermore maintaining soil P fertility is a crucial if agriculture is to achieve the productivity targets set by a growing world population.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:676712 |
| Date | January 2015 |
| Creators | Sheil, Timothy |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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