Crop sulfur status in relation to soil sulfur determined using anion exchange membranes and Mehlich 3

Abstract

The aim of this study was to find an indicator of plant sulfur status correlating most significantly with bioavailable sulfur in soil. The indicators of plant sulfur status in shoot biomass were: sulfur concentration, mass nitrogen to sulfur (N/S) ratio, mass phosphorus to sulfur ratio and sulfur nutrition index (SNI). The bioavailable soil sulfur was determined using water extraction (S-water), Mehlich 3 extractant (S-M3) and anion exchange membranes (S-AEMs). Results cover four years (2015–2018) of on-farm trials in the Czech Republic with winter wheat, winter oilseed rape and maize, and pot experiments including spring wheat and maize. Shoot biomass of plants was sampled at the beginning of stem elongation (winter wheat, winter rape and maize in on-farm trials), during rapid growth (maize in pot experiment) and during flowering (wheat plants, winter rape). Only soils containing 0.5%–1.7% of organic carbon were studied (median 1.31%). Compared to shoot N/S ratio, sulfur concentration in shoot biomass of maize correlated stronger with bioavailable soil sulfur. However, bioavailable sulfur in soil correlated strongest and most significantly with shoot N/S ratio of winter wheat and winter rape grown in on-farm trials. Except for winter rape grown on non-calcareous soils and maize grown in pot experiment, the shoot N/S ratio correlated more significantly with S-M3 compared to S-water and S-AEM.

Keywords:

• AEM
• canola
• corn
• nitrogen
• sulfur status
• wheat

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the TAČR agency within project no. TJ01000454.