Abstract
Field experiments were conducted to observe the effects of seeding rate, sowing time, and incorporation timing of Chinese milk vetch (CMV) on the growth and yield of summer buckwheat. First, CMV was sown in late October 1998 at a rate of 3.0 gm-2 and incorporated into soil at 20, 10, and 2 days before buckwheat sowing. The amount of incorporated CMV increased with delayed incorporation timing, though there was no significant difference between the buckwheat yield with the incorporation timing. Next, CMV was sown in mid-October 1999 at the different seeding rates of 1.5 g, 3.0 g, and 6.0 gm-2 in the fields having different soil fertility levels. The amount of incorporated CMV and buckwheat yield in the infertile field were lower, though buckwheat yield was almost equal in the plots incorporated 3.0 g and 6.0 gm-2, but low in the plot of 1.5 gm-2. When CMV was sown in late November 2000, the amount of incorporated CMV and buckwheat yield were markedly low even at the seeding rate of 6 gm-2. It was revealed that seed should be sown by the end of October and the optimum seeding rate was 3.0 gm-2. When the amount of incorporated CMV was 5000 gm-2 or more at 2 days before buckwheat sowing, the reaped above ground part of CMV can be used as feed or green manure for other crops, because the stubble and underground part was sufficiently effective for improving buckwheat yield.
