Interaction between beet vinasse and iron fertilisers in the prevention of iron deficiency in lupins

BACKGROUND: Recycling of organic byproducts for use as soil amendments or fertilisers may enhance the productivity of soils. The aim of this study was to investigate the potential of sugar beet vinasse to correct iron chlorosis in crops when applied in conjunction with Fe fertilisers such as vivianite and ferrous sulfate (FS). An experiment involving two factors (Fe source and dialysed sugar beet vinasse (DBV) rate) was performed using white lupin (Lupinus albus L.) and calcareous sand as growing medium. RESULTS: Although vivianite provided lower chlorophyll contents than Fe‐chelate, dry matter production was not significantly different between the two Fe sources. Vivianite was more effective than FS in preventing iron chlorosis in white lupin, but not when DBV was applied. DBV significantly increased chlorophyll content in plants treated with FS after 3 weeks of growth. CONCLUSION: DBV increased the effect of FS in preventing iron deficiency chlorosis in white lupin. This was due, at least in part, to the inhibition of the precipitation of Fe oxides by organic compounds and to the increase in the content of Fe complexed by organic compounds in the growing medium, as revealed by sequential Fe fractionation. Copyright © 2010 Society of Chemical Industry