Relationship between soybean seed selenium and harvested grain selenium

Abstract

Field experiments were conducted on sandy loam soils in Prince Edward Island (PEI) with two cultivars of soybeans at two locations to determine the relationship between Se concentration in the seed sown and the Se concentration found in the harvested soybean crop. Seeds containing a range of Se from 0.78 to 38.5 mg kg−1 were used. These variable concentrations of seed Se were obtained in field experiments by varying the rates of seed and foliar applied Se. Grain Se concentration increased with increased Se concentration in the planted seed. A high proportion of the variation in Se concentration in the harvested soybean crop was explained by variation in the Se content of the planted seed (R2 = 0.98). The regression was calculated using averages of cultivars for both locations. From the regression equation it could be predicted that planting seed containing 24 mg Se kg−1 would produce a soybean crop containing 0.5 mg Se kg−1. When used at 200 kg soybean per tonne ration this would provide a Se concentration of 0.1 mg kg−1 assuming negligible contributions from other ingredients. Selenium concentration of 0.1 mg kg−1 in animal ration is considered adequate to protect livestock from Se deficiency diseases. Key words: Podzol soils, seed-applied Se, grain Se