Open AccessThe ecology of four annual clovers adventive in New Zealand grasslands
Author(s) -
C. C. Boswell,
Richard J. Lucas,
Michele Lonati,
A. L. Fletcher,
Derrick J. Moot
Publication year - 2003
Publication title -
grassland research and practice series
Language(s) - English
Resource type - Journals
eISSN - 2463-4751
pISSN - 0110-8581
DOI - 10.33584/rps.11.2003.3010
Subject(s) - agronomy , perennial plant , grassland , germination , arid , biology , ecology
Four annual clovers have become adapted to the dry and semi-arid grasslands in New Zealand. In the absence of competition from perennial clovers, which are adapted to sub-humid and humid environments, further spread is likely to continue. Annuals rely on high numbers of small and hard seeds for survival. Their germination is dependent on a combination of adequate soil moisture and favourable temperatures, with no evidence of a prechilling treatment required. For striated clover, germination results highlight their adaptation to cool moist autumn conditions during germination. The benefits of adventive clovers for N fixation (0.2-100 kg N ha-1) are greatest where sulphur fertiliser has been applied, the clover population is dense, and soil moisture ideal over several months, but may be nil in drought conditions. Key words: annual clovers, germination, nitrogen fixation, semi-arid grassland, Trifolium arvense, T. dubium, T. glomeratum, T. striatum