Abstract
For the purpose of determining yield curve in early sowing of oats presupposing year round utilization of soiling crops, the seeds were sown three times (early September, late September and late October). 1. The cutting periods extended from 20 to 40 days in principle and frequent cuttings were carried out with these periods. 2. For plotting yield curve, the method of least squares was applied. 3. In average total yield, the maximum yield was gained by one cutting in each sowing. 4. Concerning yield curve by frequent cutting gaining higher average total yield in each sowing, following formula was considered. 1) Sowing in early September A. In three cuttings, the first cut was made from Nov. 30 to to Dec. 30, the 2nd from Feb. 27 to March 29 and the 3rd from April 27 to May 27. First cut: y=-0.8x^2+2.68x+4.48 (0≦x≦3, 1x=10 days) 2nd cut: y=-0.66x+1.32 (0≦x≦3, 1x=10 days) 3rd cut: y=-1.325x^2+5.625x+7.415 (0≦x≦3, 1x=10 days) Where y: yield per 3.3 m^2, x: days after first cutting date. B. In two cuttings, the first cut was made from Nov. 30 to Dec. 30, the 2nd from April 27 to May 15. First cut: same as that of A above 2nd cut: y=2.41x+11.46 (0≦x≦3, 1x=6 days) 2) Sowing in late September A. In three cuttings, the first cut was made from Dec. 20 to Jan. 19, the 2nd from Feb. 20 to March 19, the 3rd from May 2 to May 23. First cut: y=0.757x+4.09 (0≦x≦3, 1x=10 days) 2nd cut: y=0.15x^2-0.53x+1.52 (0≦x≦3, 1x=9 days) 3rd cut: y=0.725x^2-2.625x+10.825 (0≦x≦3, 1x=7 days) B. In two cuttings, low cutting method was taken, the first cut being from March 1 to March 31 and the 2nd cut from May 2 to June 1. First cut: y=0.725x^2+1.235x+8.635 (0≦x≦3, 1x=10 days) 2nd cut: y=0.85x^2-1.93x+12.22 (0≦x≦3, 1x=10 days) 3) Sowing in October High cutting method was taken, the first cut being from March 1 to March 31 and the 2nd from May 18 to May 30. First cut: y=0.104x+5 (0≦x≦6, 1x=5 days) 2nd cut: y=0.148x^2-0.588x+13.61 (0≦x≦6, 1x=2 days)
