| Autor: |
Chien, S. H., Hellums, D. T., Henao, J. |
| Zdroj: |
Soil Science Society of America Journal; January 1987, Vol. 51 Issue: 1 p120-123, 4p |
| Abstrakt: |
Recently, S deficiency has become a problem in many flooded soils for rice (Oryza sativaL.) production because of the increased use of high‐analysis of N and P fertilizers that do not contain S. The objective of this study was to compare the relative agronomic effectiveness (RAE) of powdered elemental S and urea‐S melt (prilled or powdered) to that of gypsum in a pot trial using an S‐deficient Josephine soil (fine‐loamy, mixed mesic, Typic Haplozerults). The RAE value of powdered elemental S for grain yield was 78% with respect to gypsum when both fertilizers were surface broadcast onto the soil surface at rates up to 40 mg S kg−1. Prilled urea‐S melt was found to be significantly less effective than powdered urea‐S melt in terms of increasing rice grain yield at a rate of 20 mg kg−1. Placement of urea had no effect on rice response to elemental S for a given S placement method. The various S placement methods demonstrated the following order of agronomic effectiveness of elemental S: surface broadcast = incorporation > deep placement. Rice response to gypsum, on the other hand, was found to be the same, irrespective of placement method. Prilled urea‐S melt was approximately 61% as effective as gypsum in increasing rice grain yield when incorporated into the soil at 20 mg S kg−1. |
| Databáze: |
Supplemental Index |
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