Evaluation of a soil test method and plant analysis for determing the sulphur status of alluvial soils

Abstract

SummaryIn a pot experiment with soils of Alfisol, Entisol, and Inceptisol orders, the relative yield of Egyptian clover (Trifolium alexandrinum L.) was significantly correlated with Morgan's reagent (N NaOAc + HOAc, pH4.8) --extractable soil S (r = 0.88), plant S (r = 0.82), and plant N/S ratio (r = -0.77) suggesting suitability of these tests for diagnosing S deficiency. Total plant S lower than 0.21 per cent, plant N/S ratio wider than 17, and extractable soil S lower than 10ppm were indicative of S deficiency, and were suggestged therefore to be critical limits for these tests. Nitrogen and S in plant proteins were in near constant ratio of 16 and were significantly correlated (r = 0.99). Sixty one per cent of 250 surface soil samples had less than 10ppm extractable S and hence were deficient in S, suggesting a widespread S deficiency in soils under study. Extractable soil S in all soil series was significantly correlated with electrical conductivity and alkaline KMnO 4-extractable N, but not with pH, organic C, and CaCO 3.

Interlaboratory and Intralaboratory Testing of Soil Sulfate Analysis in Mollisols of the Pampas

“…Sulfur (S) deficiencies in grain and forage crops have been detected in many agricultural regions of the world (Bansal, Sharma, and Singh 1979;Gutierrez Boem, Prystupa, and Ferraris 2007;Haneklaus, Bloem, and Schnug 2008;Islam and Ponnamperuma 1982).…”