Lixiviation and Extraction of Zinc in a Calcareous Soil Treated with Zinc-Chelated Fertilizers

Abstract

When Zn is added to calcareous soils to avoid Zn deficiencies, it can be fixed, if the source is a soluble inorganic salt, and leached, if it is a stable complex. Relative mobilities of Zn−EDTA and Zn−lignosulfonate (LS) chelates added to calcareous soil columns as coated and uncoated fertilizers were determined. Zn−EDTA migrated and distributed throughout the columns. About 51% of the Zn was leached with uncoated fertilizers but only about 10% when coated fertilizers were used. Zn−LS migrated very little, especially with coated fertilizers; the Zn remained mostly in the upper zone of the column and was not leached. The distribution of the added Zn between different fractions of soil was determined by a sequential extraction procedure. When Zn−EDTA was added, the percentage of the most labile fractions increased slightly with respect to the control soil throughout the entire profile of the column. Zn−LS displayed higher increases in the most labile fractions but only in the top layer of the column. Correlations between the extracted fractions (P < 0.001%) showed that in general a dynamic equilibrium existed between them. DTPA-extractable Zn correlated (P < 0.001%) with the two most labile fractions and to a lesser extent with the nonbioavailable forms. Comparisons between coated and uncoated fertilizers show that the presence of coatings benefits Zn−EDTA fertilizers, decreasing the leaching and increasing the amount of biavailable Zn, but had no beneficial effect for Zn−LS fertilizers. Keywords: Zn chelates; controlled-release; calcareous soil columns; speciation; leaching

Use of the stable isotope 57 Fe to track the efficacy of the foliar application of lignosulfonate/Fe3+ complexes to correct Fe deficiencies in cucumber plants

“…This fact was confirmed by a soil column experiment filled with a pH 6.5 soil and irrigated with a pH 7.5 buffered nutrient solution. A low mobility of the Fe‐LS complex through the soil column was observed 8. This was also shown when Zn‐LS were applied to calcareous soils 9.…”

Relative performance of chelated zinc and zinc sulphate for lowland rice (Oryza sativa L.)

“…The chelating agents diethylene triamine penta-acetic acid (DTPA), hydroxyethyl ethylenediamine triacetic acid(HEDTA) and EDTA are some of the strongest synthetic chelating agents and form much stronger chelates with Zn than naturally occurring organic ligands (Norvell 1983). In general, chelating agents such as DTPA, HEDTA and EDTA have been shown to contribute largely to Zn movement in soil under conditions of excessive rainfall and irrigation (Alvarez et al 1996).…”

Effect of Zn, Fe and FYM on Interaction between Zn and Fe on Nutrient Content, Uptake and Yield of Different Varieties of Rice (Oryza sativa L.)

“…Jana et al, (2010) also observed that soil application of Zn-EDTA led to higher content and uptake of N, P, K and Zn in grain and straw of rice. Alvarez et al, (2001) reported that when Zn was added as Zn-EDTA, the amounts of the most labile fractions (watersoluble plus exchangeable and organically complexed Zn) increased throughout the entire soil profile column, which enhanced the root-cell membrane function. Activity of carbonic anhydrase (CA) is closely related to Zn content in C3 plants (Pearson et al, 1995).…”