Journal of the Indian Society of Soil Science
Year : 2010, Volume : 58, Issue : 4
First page : ( 394) Last page : ( 402)
Print ISSN : 0019-638X. Online ISSN : 0974-0228.

Interrelationships of Sulphur with Soil Properties and its Availability Index in Some Rapeseed-growing Inceptisols of Assam

Basumatari Anjali, Das K.N., Borkotoki Bikram

Department of Soil Science, Assam Agricultural University, Jorhat, 785013, Assam. daskn388@gmail.com; daskn@aau.ac.in

Received:  June,  2009; Accepted:  July,  2010.

Abstract

Interrelationships of forms of sulphur and its availability index with soil properties were investigated in some rapeseed-growing Inceptisols of Assam. The abundance of various forms of S was in the following decreasing order: total S>organic S>non-sulphate (SO₄) S>heat soluble S>available (SO₄)-S>water soluble S>adsorbed S. Amongst the S fractions, the highest and the lowest contribution to the total S pool was made by organic-S (70.3 to 76.3%) and adsorbed-S (0.5 to 1.74%), respectively. Significant positive correlations of organic-C and clay with all forms of sulphur indicated their dominant influence on sulphur status of these soils. Total, organic, heat soluble and non-SO₄-S showed significant positive correlation with sesquioxides. Organic-C was the most important determinant of sulphur availability index (SAI) (r=0.897**) followed by clay (r= 0.790**), CEC (r=0.705**) and available N (r=0.585**). Stepwise multiple regression equations revealed that organic-C had greater impact on total, organic, available, non-SO₄-S and SAI while pH impacted the heat soluble and adsorbed-S. About 10.1 to 20.0% of the investigated soils were found to be deficient in plant available S and needed S fertilization for sustainable production of mustard.

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Keywords

Forms of sulphur, soil properties, Inceptisols, Assam.

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