镁肥用量对油菜籽产量及品质的影响

Effects of magnesium application rate on yield and quality in oilseed rape(Brassica napus L.)

我国冬油菜主产区土壤缺镁严重,为明确镁肥施用在油菜增产提质上的作用,于2020/2021和2021/2022油菜种植季在江西进贤和湖南安仁开展田间试验,共设置0、15、30、45和60 kg MgO hm^(–2)5个镁肥施用量。研究了镁肥用量对油菜籽产量及其构成因子、籽粒镁含量、含油率和脂肪酸组成的影响。结果表明,施镁显著增加了油菜籽粒产量(增幅为12.0%-77.1%),当镁肥用量为21.4-45.6 kg MgO hm^(–2)时菜籽产量达到最高。与不施镁肥相比,施镁使油菜单株角果数、每角粒数和千粒重分别增加了5.0%-64.7%、1.8%-19.6%和7.1%-8.7%,但对收获密度影响不显著。施镁后籽粒镁含量增幅为5.0%-30.3%,含油率增加了0.63-5.11个百分点,蛋白质含量下降了1.45-2.34个百分点,籽粒含水率和硫甙含量则无明显变化。镁肥施用显著增加了单位面积籽粒产油量(14.4%-83.4%)和蛋白产量(9.8%-68.1%),当镁肥用量为30-45 MgO hm^(–2)时产油量达到最高。从脂肪酸组成来看,施镁对籽粒油酸含量和亚麻酸含量有提升作用,增幅分别为4.4%-16.0%和3.8%-40.8%,但降低了亚油酸含量,降幅为1.2%-10.1%,对其他脂肪酸组分的影响则较小。综上,施镁有利于提高油菜产量及其构成因子(单株角果数、每角粒数、千粒重)、籽粒含油量及不饱和脂肪酸含量,实现产量和品质的协同提升。当镁肥用量为30-45 MgO hm^(–2)时产量与产油量均达到较高水平。

Magnesium(Mg)deficiency is one of the most serious problems in the main producing area of rapeseed in China.To evaluate the effectiveness of Mg fertilizer on seed yield and quality,field experiments were conducted at Jinxian,Jiangxi province and Anren,Hunan province during the 2020/2021 and 2021/2022 cropping seasons,with five Mg application rates(0,15,30,45,and 60 kg MgO hm^(–2)).Rapeseed yield and its components,seed Mg content,oil content,and fatty acid components were analyzed.The results showed that Mg application increased rapeseed yield by 12.0%–77.1%.Mg application rate for maximal seed yield was 21.4–45.6 kg MgO hm^(–2).Mg fertilizer increased the number of pods,number of seeds per pod,and 1000-weight by 5.0%–64.7%,1.8%–19.6%,and 7.1%–8.7%,respectively,which had no significant effect on harvest density.After the application of Mg fertilizer,seed Mg concentration increased by 5.0%–30.3%,and the oil content increased by 0.63%–5.11%,but protein content reduced by 1.45%-2.34%.Seed water and glucosinolate concentration were independent of Mg nutrition.Mg application increased oil yield and protein yield per unit area by 14.4%-83.4%and 9.8%-68.1%,respectively.The amount of Mg fertilizer corresponding to the highest oil production was 30-45 MgO hm-2.As for fatty acid composition,Mg application increased the content of oleic acid and linolenic acid in seeds by 4.4%-16.0%and 3.8%-40.8%,respectively,but decreased the content of linoleic acid by 1.2%-10.1%,which had a non-significant effect on other fatty acid components.In conclusion,Mg application was crucial to the synergistic improvement of yield and quality by improving seed yield and its components(the number of pods per plant,the number of grains per pod,and 1000-grain weight),seed oil content,and the unsaturated fatty acid content.The amount of Mg fertilizer corresponding to the highest yield and oil production was 30-45 MgO hm-2.