硫肥对双低油菜产量与品质的影响

在澳大利亚新南威尔士州缺硫土壤上进行了硫、氮不同水平组合对双低油菜(Canola)的影响试验。结果表明,试验条件下施用硫肥可显著提高油菜产量及含油量。低硫(S10)或无硫(So)条件下,一定量的氮肥(N80)可提高子粒内的含硫量,但高硫条件下,高量氮肥则降低含硫量。植株体内的含硫量随生育进程趋于降低。施硫处理在抽苔期出现一吸硫高峰,而对照呈指数下降;但在开花期与角果充实期则保持相对稳定。氮肥对生长前期(莲座期与抽苔期)植株(茎、叶)含硫量的影响不显著,而中、后期(开花、角果充实期),则随施氮量的增加而显著降低。高量氮肥(N160)会降低子粒内的硫代葡萄糖甙含量;施硫,特别是在高施硫量条件下,其含量则明显增加,但仍远低于子粒硫代葡萄糖甙40mol/g的标准,因而不会影响脱油饼粕的饲喂质量。

EFFECT OF SULFUR APPLICATION ON YIELD AND QUALITY OF CANOLA DOUBLE LOW OILSEED RAPE (BRASSICA NAPUS CV. OSCAR)

Sulfur (S) and nitrogen (N) applicaton to canola (double low oilseed rape) was conducted on S deficient soil in New South Wales, Australia. The results indicated that sulfur supply increased seed yield and oil content significantly, certain amount of N (eg. N80) with low (S₁₀) or without S (S₀) might increase seed S concentration but high rate N with high S could depress it. Generally, S concentration in vegetative parts were decreased with plant development. There was a peak of S uptake appearing at stem elongation with S supply (Y-0. 0156X²+0. 0012X+0.5276, R²=0. 804) but exponential decrease (Y=3. 7205X^-0.595, (R²=0.935) without S. The S concentration in vegetative parts remained relatively stable during flowering and pod filling stages. There was no significant effect of N supply on vegetative S concentration during earlier growth stages (eg. rosette and stem elongation) but the concentration at middle and late stages (eg. flowering and pod filling) was significantly decreased by N application. Total glucosinolates were decreased by high rate N (N₁₆₀) but increased by S because of a close correlation between seed S and glucosinolate concentration (Y=1.1572e^3.5289x, R²=0.8273). However, even at highest rate of S, the glucosinolate concentration was still far below the standard (40u mol/g in whole seed) so that the oil free meal would not affect feeding quality of animals.