What factors are affecting the availability of zinc in soils to plants?
The zinc which is available to plants is that present in the soil solution or is adsorbed in a labile (easily desorbed) form. The soil factors affecting the availability of zinc to plants are those which control the amount of zinc in the soil solution and its sorption – desorption from/into the soil solution. These factors include: the total zinc content, pH, organic matter content, calcium carbonate content, redox conditions, microbial activity in the rhizosphere, soil moisture status, concentrations of other trace elements, concentrations of macro – nutrients, especially phosphorus and climate. Some of these factors are briefly summarised here in a practical crop production context: • Sandy soils and acid highly leached soils with low total and plant -available zinc concentrations are highly prone to zinc deficiency. • Availability of zinc decreases with increasing soil pH due to increased adsorptive capacity, the formation of hydrolysed forms of zinc, possible chemisorption on calci
