Effect of Nitrogen Fertilisation and Inoculation with Bradyrhizobium japonicum on the Fatty Acid Profile of Soybean (Glycine max (L.) Merrill) Seeds

Abstract

Soybean is a valuable protein and oilseed crop ranked among the most significant of the major crops. Field experiments were carried out in 2016–2019 in South-East Poland. The influence of soybean cultivars (Aldana, Annushka), nitrogen fertilizer (0, 30, 60 kg∙ha−1 N) and inoculation with B. japonicum (control, HiStick® Soy, Nitragina) on the content of fatty acids (FA) in soybean seeds was investigated in a three-factorial experiment. This study confirms the genetic determinants of fatty acid composition in soybean seeds and their differential accumulation levels for C16:0, C16:1, C18:1n9, C18:2, C18:3, and C20:0 as well saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Increasing the rate from 30 to 60 kg ha−1 N did not produce the expected changes, suggesting the use of only a “starter” rate of 30 kg ha−1 N. Inoculation of soybean seeds with a strain of Bradyrhizobium japonicum (HiStick® Soy, BASF, Littlehampton, UK and Nitragina, Institute of Soil Science and Plant Cultivation–State Research Institute, Puławy, Poland) is recommended as it will cause a decrease in SFA and C16:0 acid levels. This is considered nutritionally beneficial as its contribution to total fatty acids determines the hypercholesterolemic index, and it is the third most accumulated fatty acid in soybean seeds. The interaction of cultivars and inoculation formulation on fatty acid content of soybean seeds was demonstrated. An increase in the value of C16:0 content resulted in a decrease in the accumulation of C18:1, C18:2, and C18:3 acids. The content of each decreased by almost one unit for every 1% increase in C16:0 content. The dominant effect of weather conditions on the FA profile and C18:2n6/C18:3n3 ratio was demonstrated. This suggests a need for further evaluation of the genetic progress of soybean cultivars with respect to fatty acid composition and content under varying habitat conditions.

Quality Evaluation Indices for Soybean Oil in Relation to Cultivar, Application of N Fertiliser and Seed Inoculation with Bradyrhizobium japonicum

“…The detailed methodology of the field experiment is presented in the work of Szpunar-Krok et al [ 53 ].…”

“…Qualitative interpretation of the chromatograms was performed by comparing the retention times of fatty acid methyl esters in the test sample with those of Supelco 37 fatty acid methyl ester matrices. The detailed methodology for determining the FA profile and its content in soybean seeds is given in the work by Szpunar-Krok et al [ 53 ].…”

Assessing the Quality of Burkina Faso Soybeans Based on Fatty Acid Composition and Pesticide Residue Contamination

“…Pentadecanoid acid was present in the soybean of the imported soybean variety G196, but absent in the soybean of variety G197 grown in Burkina Faso. In 2021, Szpunar-Krok and Wondołowska-Grabowska showed that soybean fat quality indices were significantly influenced by cultivar type [ 26 ]. For the evaluation of the effect of cultural practices on the nutritional quality of soybeans, the molecular characterization of pesticides allowed for the detection of the four main families of pesticides: carbamates, orgnanochlorines, organophosphates, pyrethroids, as well as triazines, strobin and benzoylurea derivatives.…”

Side dressing nitrogen fertilization in soybean in association with inoculation

“…For this, investigations on mineral nitrogen in soybean seek to better understand the dynamics between BNF and additional supplementation with nitrogen. Among the various factors investigated, we found studies that associate nitrogen doses with sowing density (FERREIRA et al, 2016;WERNER et al, 2016); supplementary mineral nitrogen with its effects on oil and/or protein contents in grains (HAMAGUCHI et al, 2020;MOREIRA et al, 2017;PRUSIŃSKI, BATURO-CIEŚNIEWSKA, BOROWSKA, 2020;SZPUNAR-KROK et al, 2021); nitrogen supply with seed quality (ZUFFO et al, 2021); as well as those that investigate the dynamics of nitrogen absorption in the initial stages of soybean, in which the BNF is not yet meeting the requirements of the crop (CONCEIÇÃO et al, 2018); in addition to studies on the effects of fixed nitrogen in the subsequent crop (GOSS et al, 2002;ZUFFO et al, 2022); and studies on foliar nitrogen and their effects on carbon and oxidative metabolism (RODRIGUES et al, 2021). Bahry et al (2014) pointed out that, in some edaphoclimatic conditions, nitrogen from BNF is not enough to meet the requirements of the crop and its limitation may compromise the final productivity, evidencing that the application of nitrogen in the reproductive phase of soybean positively influences some yield components.…”