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Agronomic Effectiveness of Granular Nitrogen/Phosphorus Fertilizers Containing Elemental Sulfur with and without Ammonium Sulfate: A Review
Author(s) -
Chien Sen H.,
Teixeira Luiz A.,
Cantarella Heitor,
Rehm George W.,
Grant Cynthia A.,
Gearhart Mercedes M.
Publication year - 2016
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2015.0276
Subject(s) - diammonium phosphate , sulfur , phosphorus , agronomy , fertilizer , nitrogen , soil fertility , ammonium sulfate , environmental science , chemistry , phosphate fertilizer , phosphate , soil water , soil science , biology , organic chemistry , chromatography
Deficiency of S in soils has become a soil fertility issue worldwide because of a decrease in S deposition from air to soil due to legislation and increased crop removal. Continuous use of high‐analysis nitrogen/phosphorus (NP) fertilizers lacking in S further exacerbates the S deficiency for crop production. Several newly developed granular NP fertilizers such as monoammonium phosphate (MAP), diammonium phosphate (DAP), and triple superphosphate (TSP) containing micronized elemental sulfur (ES) with/without ammonium sulfate (AS) have been marketed to farmers. It is claimed that these products can provide available SO 4 –S through AS and ES oxidation during the growing season. The objective of this review was to carefully examine the literature that addresses the agronomic effectiveness of the granular NP–ES or NP– (ES+AS) fertilizer products. The review shows that oxidation of ES particles in granular NP fertilizers is generally nil or inadequate to provide available S to seasonal (or first) crops in greenhouse studies. This is due to the negative locality effect on granular ES oxidation. In contrast, available S can be obtained from the associated AS component of the granular (ES+AS). Under field conditions, limited studies showed these granular (ES+AS) were as effective as SO 4 –based sources at a high single S rate, but lack of data at multiple S rates. The detailed evaluation of available data so far often shows that the granular NP fertilizers containing ES or (ES+AS) cannot provide available S as compared with traditional SO 4 –based S sources for season‐long or first field crops. Sulfur nutrient is important to crop growth to produce maximum crop yield. Several new S fertilizers are marketed to farmers often without scientific data to support the fertilizer producers’ claims. This review article examines the available data to check the claims; the results often cannot validate the claims.