Abstract
Effect of soil compaction on the emergence of wheat seedlings was studied d.aring two cropping seasons. A compaction pressure of L55 x. Nfrn2 was managed through the transport wheel of a grai a drill used in planting operations. The emergence was found faster and greater in the compacted soil. The desirable response of compaction may be associated with a better soil-seed contact coupled with greater soil moisture availability.
IN TRODUCTION
There are a number of factors that influence the germination of seeds. Some of them which are of interest in analyzing the grain drift performance and developing improved deigns, are opening the seed furrow to a proper depth, metering, depositing, covering and compacting the seed to a proper degree, The grain drills currently used in Pakistan are not equipped to cover and com-pact the seeds, whereas Smith 062), Kepner et al. (1972) and Sheikh (1979) indicated, that both compacting and covering operations affect the ernergenco of seedlings. The present study was undertaken to investigate the effects of tillage and compaction on the emergence of seedlings,
MATERIAL AND METHODS
This experiment was conducted in silty loam soil at the Univers;ty of Agriculture, Faisalabad, Pakistan. A carefully calibrated tractor drawn grain drill was used for planting wheat seeds. Ail the Feed rows made by the grain drill were left uncovered and =compacted except. the one preceded by the transport wheel which served as a compaction device. The pressure exerted by the transport wheel as calculated from field measurements was 1.55 x 101 N/ m2, The wheel being wider than the seed furrow reasonably covered the seeds before compacting then).
