Investigation into the effect of physical soil conditions in the seed bed on the emergence of spring oats
Thow, R. F.
The investigation arose from the observation made durlng advisory work that poor establishment occurred in Spring Oats the cause of which could only be attributed to the physical condition of the seed bed. Other possible factors such as poor seed germination, disease, deficiency or excess of soil nutrients had been eliminated and neither waterlogging nor drought were present. The work was performed in three stages: 1. Field Survey, Spring 1956. 2. Field Trial, Spring 1955. 3. Greenhouse Pot Experiments, 1956-1957. A rough tilth will reduce establishment in Spring Oats as compared with a fine tilth, but the difference will be greatly reduced by a liberal water supply. Under a moderate water supply an increment in the proportion of 1/32" - 1/4" particle fraction will increase establishment. The 1/4" - 1+1/4" appeared to have little effect. In view of Edwards, 1957, finding that an increase in fineness of tilth from 1/2" to 1 mm. brought about a considerable increase in emergence of Winter Oats, it is probable that the effect of this fraction was not detected due to the design of the experiment. An increase in the 1+1/4" - 2+1/4" particle fraction reduced establishment but up to 15-20% by weight this effect is negligible. Plant height in the early stages of growth (3-5 weeks after sowing) is strongly influenced by water supply, an excess or deficiency reducing height. The effect of tilth on height was due to an interaction with water supply.