Sulfur availability depends upon the distribution of S forms in soil, interaction among them, and soil microbial properties. Organic amendments play a vital role in maintaining adequate S reserves in soil. However, two important questions in this regard are (i) the effect of microbial activity on sulfur oxidation in soil, and (ii) the relationship of sulfur fractions to available S pool in soil. The present experiment was designed to assess the effect of organic amendments on sulfur fractions, availability, and microbial properties in soil. Two alkaline subtropical soils belonging to Missa ( silt loam Typic Ustochrept ) and Kahuta ( sandy loam Udic Haplustalf ) soil series were amended with organic amendments, viz. farmyard manure (FYM), poultry litter (PL), and sugarcane filter cake (SF), at 1% w/w and incubated at 25 °C for 56 days maintaining soil moisture at 50% WHC. CO 2 -C evolution rate, the ∑CO 2 -C, and also the ∑CO 2 -C to microbial biomass C differed with the soils and were higher in poultry litter–amended soils. Dissolved organic C (DOC), microbial biomass C (MBC), and dehydrogenase activity (DHA) were also higher in poultry litter while the microbial biomass S (MBS) and arylsulfatase activity (ASA) were higher in the sugarcane filter cake–amended soils. Organic amendments significantly increased plant-available SO 4 2− and enhanced C-bonded S, and inorganic S fractions in the following order: sugarcane filter cake > poultry litter > farmyard manure. Organic amendments significantly improved microbial activity and S availability in soil depending upon their labile organic C, organic S, and available S contents.

中文翻译：

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受有机修正影响的碱性亚热带土壤中硫的分布和有效性

硫的有效性取决于土壤中硫形式的分布、它们之间的相互作用以及土壤微生物特性。有机改良剂在保持土壤中充足的硫储量方面起着至关重要的作用。然而，这方面的两个重要问题是 (i) 微生物活动对土壤中硫氧化的影响，以及 (ii) 硫含量与土壤中可用 S 库的关系。本实验旨在评估有机改良剂对土壤中硫含量、有效性和微生物特性的影响。属于 Missa（粉砂壤土 Typic Ustochrept）和 Kahuta（砂壤土 Udic Haplustalf）土壤系列的两种碱性亚热带土壤用有机改良剂进行了修正，即。农家肥 (FYM)、家禽垫料 (PL) 和甘蔗滤饼 (SF)，1% w/w 并在 25 °C 下培养 56 天，将土壤水分保持在 50% WHC。CO 2 -C 演化速率、∑CO 2 -C 以及∑CO 2 -C 对微生物生物量 C 的影响因土壤而异，并且在家禽垫料改良的土壤中更高。家禽垫料中的溶解有机碳 (DOC)、微生物生物量碳 (MBC) 和脱氢酶活性 (DHA) 也较高，而甘蔗滤饼改良土壤中的微生物生物量 S (MBS) 和芳基硫酸酯酶活性 (ASA) 较高. 有机添加物按以下顺序显着增加了植物可利用的 SO 4 2- 和增强的 C 键合 S 和无机 S 部分：甘蔗滤饼 > 家禽垫料 > 农家肥。有机改良剂显着提高了土壤中的微生物活性和 S 可用性，这取决于它们的不稳定有机 C、有机 S 和有效 S 含量。