Effect of potassium application on the transformation of zinc fractions in soil and on the zinc nutrition of wetland rice

Abstract

ZusammenfassungThe eNect of different levels of K application on the transformation of native as well as applied Zn fractions in a rice-growing soil was studied under two moisture regimes viz. waterlogged and alternate waterlogged and saturation. Application of K caused an increase in the water-soluble plus exchangeable. organically complexed and carbonates, and other acid-soluble mineral fractions of native soil Zn. Application of K also caused an increase in the transformation of applied Zn into all the above three fractions of the element in soil. The above effects of K were more pronounced in soil under waterlogged than under alternate waterlogged and non-waterlogged moisture regimes.The results of a greenhouse experiment showed that K application caused an increase in Zn uptake and per cent utilization of both native and added Zn by rice. This was attributed to the increase in the watersoluble plus exchangeable and organically complexed forms of Zn in soil due to K application.

Distribution of Copper and Zinc Fractions in Red Soil as Influenced by Fertilizer Application

“…Both increased soluble plus exchangeable and decreased weakly specifically adsorbed metals may be due to the competitive exchange between K and heavy metal ions on soil solids. The results of this study are in agreement with the findings of Mandal et al (12), who reported that addition of K at 25 -50 mg K kg Ϫ1 increased Zn in the soluble plus exchangeable fraction.…”

“…Phosphorus addition was found to cause a reduction in the water soluble plus exchangeable and an increase in the amorphous and crystalline sequioxide bound fractions of zinc (11). Application of K can increase the water soluble plus exchangeable, organically complexed and carbonate fractions of soil Zn (12).…”

Phosphorous and lime-induced zinc fractions transformations in Zn deficit tropical paddy soils

“…Soil solution thermodynamic findings for Zn behaviour in flooded soils showed soluble P was the most effective in Zn immobilization through lower soluble Zn products formation (Mandal and Mandal 1990;Rupa et al 2003).…”

“…On the other hand, formation of Fe 2+ and Mn 2+ in soil under the flooded condition, compete with Zn 2+ for exchange sites and thus restricts the entry of applied Zn into the exchange complexes sites. The increase in soluble Fe 2+ and Mn 2+ may also displace some of the Zn that already present in the exchange complex leading to its reaction with P in the solution phase with formation of compounds with lower solubility (Mandal and Mandal 1990;Shuman 1985;Shuman 1998).…”

“…As illustrated in Table 3, although added P increased the Amor Zn fractions concentration and the increment also positively related to the P levels, but was not significant (Tables 9 and 10). It can be explained by Zn adsorption with hydrous oxides due to low or moderate enrichment of the oxides with phosphate (Benjamin and Bloom 1981;Mandal and Mandal 1990). Phosphorus sorption can increase the surface negative charge or potential (or reduced surface positive charge), or precipitation a new adsorbing plane of Fe phosphate on surface of the oxides.…”