The effects on grass Yield, and their implications for dairy farming
In this section, we test the temperature-hay yield model developed in Section 2, using the long-term measurements on permanent grasslands from experimental stations in Iceland. Data on national average hay yield, used in Section 2, are only an indirect measure of grass growth, however. Here, and fol...
| Main Authors: | , , |
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| Format: | Book Part |
| Language: | unknown |
| Published: |
Springer
1988
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| Subjects: | |
| Online Access: | https://pure.iiasa.ac.at/id/eprint/13016/ https://doi.org/10.1007/978-94-009-2943-2_15 |
| Summary: | In this section, we test the temperature-hay yield model developed in Section 2, using the long-term measurements on permanent grasslands from experimental stations in Iceland. Data on national average hay yield, used in Section 2, are only an indirect measure of grass growth, however. Here, and following some preliminary investigations (Björnsson, 1975, 1984), estimates of the effects of climatic variations are refined to consider the yield response to varying fertilizer applications and management practices under different temperature scenarios. Estimates of grass growth are made for five of the six scenarios described in Subsection 1.10: (1) Scenario I — the baseline period (1951–1980). (2) Scenario II — the coolest recorded decade (1859–1868). (3) Scenario IV+ — the ensemble of the 10 warmest years (1931–1984) slightly modified to give a warm anomaly comparable with the cool anomaly in Scenario II. (4) Scenario V — the GISS-derived 2 × CO2 scenario. (5) Scenario VI — the extreme year scenario, defined as a year in which mean annual temperature deviates by at least two standard deviations from the period average (see Subsection 3.4.1). Finally, the implications of these effects for the quality and utilization of herbage are examined with respect to Icelandic dairy production. |
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