Published online by Cambridge University Press: 03 October 2008
The apparent success of overdrilling in improving poor grazing pasture in other temperate climates led to an investigation of the technique under British conditions. With the development of a suitable machine, both for controlling competition and for drilling seeds and fertilizers simultaneously into established pasture, field trials were initiated in 1961 and 1962. Despite the achievement of satisfactory furrows for germination, the subsequent emergence and establishment of improved grasses and white clover was poor. This was thought to be due to various factors, particularly to competition from the short vigorous lowland swards, but also to unsatisfactory furrow environments where difficulties were experienced in covering seeds adequately, and in protecting seedlings from desiccation. Even when an overall application of herbicide was used to control competition, the seedlings were slow to colonize the bare ground and appeared to be particularly vulnerable to desiccation where vegetation was absent. Under the conditions of sward and climate at Aberystwyth, overdrilling by itself appears to offer no promise as a means of grassland improvement.