Liu Xin-wei, Duan Bi-huil, Xia Quan-jie, Jiao Wei, Guo Zai-hua, Hu Cheng-xiao, Zhao Zhu-qing
Huan Jing Ke Xue. 2014 Sep;35(9):3564-71.
The high-quality, high-yield rape (Brassica napus L. cv. Xiangnongyou 571) was chosen as the experimental material to undergo seedling stage soil cultivation and solution cultivation. This study was aimed to investigate the effects of sulfur (S) on the fraction and species of amend selenium (Se) in soil by applying S fertilizer, and to reveal the mechanism through which S controls the Se uptake of rape. The results showed that applications of both Se at 5 mg.kg-1 and S at 150 mg.kg-1 could provide some boost to rape growth, however such boost was unremarkable; S application could significantly reduce Se content in shoots and roots by as much as 64. 0% and 39. 1% , respectively; S application could significantly decrease the pH value and increase the organic matter content by as much as 0. 65 units and 1.76 g.kg-1 , respectively; S application could significantly decrease soluble Se and Fe/Mn oxide-bound Se, and significantly increase organic matter-bound Se, however, there was no remarkable effect on exchangeable and residual Se. S could significantly decrease the content of Se(IV) in the soluble Se and significantly increase the content of Se(IV) in the exchangeable Se, with remarkable decrease in Se(VI) content in both fractions, and no remarkable effect on Se(II). S had a profound effect on the uptake of Se by rape seedlings when Se( IV) and Se( VI) were applied. The Se contents in shoot and root of the Se( VI)-treated rape were 7.3 and 3.2 times respectively as high as that of the Se( IV)-treated rape, while with a S rate of 2 mmolL-1, their Se contents were lower than 32.6% and 8.7% of that of the Se(IV)-treated rape. In conclusion, in addition to improving crop growth, appropriate amount of S fertilizer could also reduce soil pH and increase organic content, causing available Se in soil to be Fe/Mn oxide-bound and organic matter-bound, and retarding its transformation to Se( VI), thus reducing Se uptake by rape. This has significant value for regulation of Se content in crops from Se-rich regions, ensuring food quality and safety, benefiting the long-term use of soil Se resources and regional economic development.
选用优质高产油菜（甘蓝型油菜品种湘农油571）作为试验材料，进行苗期土培和水培试验。本研究旨在通过施用硫肥，探讨硫（S）对土壤中可交换态硒（Se）形态和种类的影响，并揭示硫调控油菜对硒吸收的机制。结果表明，施用5 mg·kg-1的硒和150 mg·kg-1的硫均能对油菜生长有一定促进作用，但效果不显著；施硫能显著降低地上部和根部的硒含量，降幅分别高达64.0%和39.1%；施硫能显著降低土壤pH值，使土壤有机质含量增加1.76 g·kg-1，增幅达0.65个单位；施硫能显著降低土壤中可溶性硒和铁/锰氧化物结合态硒含量，显著增加土壤中有机质结合态硒含量，但对交换态和残渣态硒无显著影响；施硫能显著降低可溶性硒中硒（IV）含量，显著增加交换态硒中硒（IV）含量，使两种形态硒中硒（VI）含量显著降低，对硒（II）无显著影响；在施用硒（IV）和硒（VI）时，硫对油菜幼苗吸收硒有显著影响。硒（VI）处理的油菜地上部和根部硒含量分别是硒（IV）处理的7.3倍和3.2倍，而在硫浓度为2 mmol·L-1时，其硒含量分别比硒（IV）处理低32.6%和8.7%。综上所述，适量硫肥除了能促进作物生长外，还能降低土壤pH值，增加土壤有机质含量，使土壤中有效态硒向铁/锰氧化物结合态和有机质结合态转化，延缓其向硒（VI）的转化，从而降低油菜对硒的吸收。这对于调控富硒地区作物硒含量、保障粮食质量安全、有利于土壤硒资源的长期利用和区域经济发展具有重要意义。
