Potential impacts of soil tillage system on isoflavone concentration of soybean as functional food ingredients

Authors: MURESAN, LILIANA - University Of Agricultural Sciences And Veterinary Medicine - Romania; CLAPA, DOINA - University Of Agricultural Sciences And Veterinary Medicine - Romania; BORSAL, ORSOLYA - University Of Agricultural Sciences And Veterinary Medicine - Romania; TEODOR, RUSU - University Of Agricultural Sciences And Veterinary Medicine - Romania; Wang, Thomas - Tom; Park, Jae

Submitted to: Land
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2020
Publication Date: 10/12/2020
Citation: Muresan, L., Clapa, D., Borsal, O., Teodor, R., Wang, T.T., Park, J.B. 2020. Potential impacts of soil tillage system on isoflavone concentration of soybean as functional food ingredients. Land. 9(10):386. https://doi.org/10.3390/land9100386.
DOI: https://doi.org/10.3390/land9100386

Interpretive Summary: Soybeans are consumed worldwide due to their high nutrient contents and bioactive components. Soybeans are also a very good source for isoflavones. However, the contents of isoflavones in soybeans have been reported to be influenced by many factors such as genotype, environmental condition (e.g., temperature, precipitation), soil management system and weed control. Romania is one of the major soybean producers in Europe, but there is no information about the potential effects of these factors on soybeans cultivated in Romania. Therefore, in this study, we investigated the potential effects of soil management systems, climatic conditions and weed controls on the yield and isoflavone content in the conventional soybean cultivar/Felix grown in Romania. Also, the potential difference of isoflavone contents in Felix soybeans from Romania and GM soybeans from America was investigated to gauge their disparity. Our results suggest that soil management systems may have less distinctive effects on the yields and isoflavone contents than climatic conditions. However, weed control was found to improve the yields significantly with less than 10% variation in total isoflavone contents. In addition, the Felix variety grown in Romania was found to contain higher contents of daidzin and genistin than GM soybeans from America, suggesting that the Felix variety might be a better source for these isoflavones. Our findings provide information about the potential effects of environmental condition, soil management system and weed control on soybeans cultivated in Romania and isoflavone disparity in soybeans from Romania and America.

Technical Abstract: Soybeans are considered to be the main natural source of isoflavones among legumes, but the isoflavone content is highly influenced by external factors such as climatic conditions and cultivation techniques. Nevertheless, country-specific information about the influence of soil management systems on yield and isoflavone content is very limited; thus, further research is needed to shed more light on the decisive factors. Therefore, in this research, nine field experiments were established in Romania to investigate how the climatic factors and country-specific different soil management systems together with weed control influence crop yield and isoflavone content of soybeans. Our results indicated that the climatic conditions of the area significantly influenced both the soybean production and total isoflavone content; the highest yield (2109 kg/ha) and total isoflavone content (8101 µg/g) were recorded in 2016 when the annual average temperature and precipitation also reached their highest values. Our results also suggest that soil management systems may have less distinctive effects on the yields and isoflavone contents than climatic conditions. However, weed control was found to improve the yields significantly (P < 0.05) with less than 10% variation in the total isoflavone contents. In addition, the Felix variety grown in Romania was found to contain higher contents of daidzin and genistin than GM soybeans from America (P < 0.05), suggesting that the Felix variety might be a better source for these isoflavones. Altogether, our findings appear to demonstrate that climatic factors are more decisive regarding soybean yield and isoflavone content than country-specific soil management systems. However, the soil management system can be used with weed control to maximize the aspect of crop yield versus isoflavone content in Romania.