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Sulfur mineralization in two soils amended with organic manures, crop residues, and green manures
Author(s) -
Sammi Reddy Kotha,
Singh Muneshwar,
Swarup Anand,
Subba Rao Annangi,
Singh Kamlesh Narain
Publication year - 2002
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/1522-2624(200204)165:2<167::aid-jpln167>3.0.co;2-1
Subject(s) - inceptisol , soil water , mineralization (soil science) , vertisol , chemistry , green manure , agronomy , manure , total organic carbon , alfisol , gliricidia sepium , environmental chemistry , environmental science , soil science , biology
The mineralization of sulfur (S) was investigated in a Vertisol and an Inceptisol amended with organic manures, green manures, and crop residues. Field‐moist soils amended with 10 g kg —1 of organic materials were mixed with glass beads, placed in pyrex leaching tubes, leached with 0.01 M CaCl 2 to remove the mineral S and incubated at 30 °C. The leachates were collected every fortnight for 16 weeks and analyzed for SO 4 ‐S. The amount of S mineralized in control and in manure‐amended soils was highest in the first week and decreased steadily thereafter. The total S mineralized in amended soils varied considerably depending on the type of organic materials incorporated and soil used. The cumulative amounts of S mineralized in amended soils ranged from 6.98 mg S (kg soil) —1 in Inceptisol amended with wheat straw to 34.38 mg S (kg soil) —1 in Vertisol amended with farmyard manure (FYM). Expressed as a percentage of the S added to soils, the S mineralized was higher in FYM treated soils (63.5 to 67.3 %) as compared to poultry manure amended soils (60.5 to 62.3 %). Similarly the percentage of S mineralization from subabul (Leucaena leucocephala) loppings was higher (53.6 to 55.5 %) than that from gliricidia (Gliricidia sepium) loppings (50.3 to 51.1 %). Regression analysis clearly indicated the dependence of S mineralization on the C : S ratio of the organic materials added to soil. The addition of organic amendments resulted in net immobilization of S when the C : S ratio was above 290:1 in Vertisol and 349:1 in Inceptisol. The mineralizable S pool (S o ) and first‐order rate constant (k) varied considerably among the different types of organic materials added and soil. The S o values of FYM treated soils were higher than in subabul, gliricidia, and poultry manure treated soils.