Uptake of sodium, boron and heavy metals from an alkaline top layer and translocation to leaves and lower roots of Vitis vinifera during a long time duplex study

In a three years field experiment with Vitis vinifera grown up in lysimeter pots with Keuper or Loess as soil substrates, the effects of an alkaline t op layer with high sodium, boron and heavy metal content (municipal solid w aste incinerator bottom slag) on the uptake and translocation of these elem ents from roots developing in this layer to leaves and downward translocati on to roots in the bottom layer (Keuper or Loess) were studied. Control pla nts and slag treated vine plants exhibited a similar pattern of composition in respect to main elements such as N, S, P, Mg, K, indicating an acceptab le nutrition status in the presence of a top slag layer, except that leaves of slag plants showed slight symptoms of phosphate deficiency. The high so dium concentration in the alkaline top layer caused a significant increase of the sodium content in the roots developing in this layer and to a lesser extent in the roots of the bottom layer. However, no increase was observed in the sodium content of leaves demonstrating sodium exclusion from vine l eaves. The heavy metal burden of the alkaline top layer caused a strong inc rease of lead, cadmium, copper, zinc, and chromium contents of the roots of this layer. The corresponding values for roots in the bottom layer were mu ch lower and no significant differences between control and slag treated pl ants were observed. Similar applied to the leaves, the heavy metal contents of which were significantly lower than that of the roots of the bottom lay er. Thus also heavy metals are largely excluded from the transport from the rootstock to the scions. The only element exhibiting a large transfer from the polluted alkaline top layer to the vine leaves and roots in the bottom layer was boron. This element accumulated in all organs of the vine plants treated with slag, particular in the leaves, where its concentration went up almost close to limits of phytotoxicity. Data are discussed in respect t o potential hazards of municipal waste incinerator bottom slag to the envir onment if this material is used as construction and support material.