大田追施硫肥对双低油菜产量与品质的影响

硫酸盐肥料以S10或40kg／hm2分别在油菜的出苗期、莲座期、现蕾期、抽薹期及初花期施入缺硫土壤，并在出苗期结合施用氮肥N80或160kg／hm2。结果表明，对照区植株在抽薹期表现出严重的缺硫症状，特别是单施N160kg／hm2的小区。追施S10kg／hm2可显著提高油菜产量及含油量，但追施时期间差异未达到显著性水准，这一施用量明显不足，油菜籽产量远低于施S40kg／hm2处理。迟于花期追施S40kg／hm2，籽粒产量较前期减少约20％。此外，施S40kg／hm2还可明显提高籽粒的蛋白质含量。对缺硫植株，籽粒N：S比大于10，而供硫适宜植株为7．5。总硫代葡萄糖甙含量随施硫量的增加而提高，且后期追施明显高于前期。

EFFECT OF SULPHUR TOPDRESSING ON YIELD AND QUALITY OF DOUBLE LOW OILSEED RAPE

Sulphate sulphur (SO42-) with S 10(S10) or 40 (S40) kg/hm2 was applied at sowing, rosette, bud visible, stem elongation and start of flowering respectively combined with nitrogen (N) 80 (N80) or 160 (N160) kg/hm2 basaldressed at sowing in order to study effects of amount and periods of topdressing on yield and quality of oilseed rape. The results indicated that plant severe symptoms of sulphur deficiency in control (S0) plot appeared during stem elongation, especially for plots with N160 only. The seed yield and oil content were increased significantly by S10 but the differences of dressing periods were not significant.However, S10 was apparently inadequate for oilseed rape normal growth because the seed yield was much lower than those of S40. The seed yield and oil content for S40 applied up to stem elongation could be same as received the same amount at sowing, but the yield was reduced approximately by 20% When S40 application was delayed until flowering. In addition,seed protein content was increased by S40 topdressed. N: S ratio was above 10 for S deficiency plants and 7. 5 for S adequate. Total glucosinolate content was increased with more S and late stages supplied.