The effects of cropping systems on selenium and glucosinolate concentrations in vegetables

Selenium (Se) and glucosinolates has been found to have beneficial effects for human health. The most common way to increase Se and glucosinolates in plants is through using inorganic fertilizers however, concerns over environmental contamination by fertilizers increased the demand for sustainable produced foods. Thus, the aim of this project was to evaluate the efficiency of different crop management strategies (catch crops, intercropping) to increase Se and glucosinolates concentrations in plants rather than the application of agrochemicals. Catch crops have been used successfully to reduce sulphur and nitrogen leaching and increase nutrient availability for the succeeding, similar beneficial effects on Se may be expected. Nitrogen and sulphur interaction have been found to influence glucosinolate concentrations in plants. Thus, controlled interspecific competition may be a useful tool for manipulating the balance of nutrient in the soil and enhance glucosinolate concentrations in plants. Our results suggested that crop management strategies may be an alternative method to increase selenium and glucosinolate concentrations in plants but further work is required to develop efficient cropping systems. Catch crops did not reduce Se leaching but incorporation of plant materials may increase Se concentrations in plants. In addition intercropping may increase glucosinolate concentrations but a careful selection of the plant species and intercropping design is needed to ensure the development of both species otherwise the effect will be limited