Bioavailability of selenium to forage crops in a sandy loam soil amended with Se-rich plant materials

• Published in: Chemosphere (Oxford) 2007, Vol.66 (9), p.1734-1743
• Main Authors: Dhillon, S.K., Hundal, B.K., Dhillon, K.S.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; bioavailability; Biological and medical sciences; Biological Availability; Brassica juncea; corn silage; crop residues; crop yield; Crops, Agricultural - metabolism; Deficiencies. Phytotoxicity of elements. Salinity; dry matter accumulation; Fluorometry; Fodder crops; forage crops; forage legumes; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grain crops; Hot water soluble Se; Incorporation; India; mineral content; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Plant Stems - chemistry; sandy loam soils; Se content; Se-rich plants; selenium; Selenium - analysis; Selenium - pharmacokinetics; Soil - analysis; soil amendments; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Sorghum - metabolism; Sorghum bicolor; sorghum silage; Trifolium - metabolism; Trifolium alexandrinum; Triticum aestivum; wheat; wheat straw; Zea mays; Zea mays - metabolism
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.07.006

Greenhouse experiments were conducted to study the bioavailability of selenium (Se) to sorghum ( Sorghum bicolor L.), maize ( Zea mays L.) and berseem ( Trifolium alexandrinum L.) fodders in a sandy loam soil amended with different levels of Se-rich wheat ( Triticum aestivum L.) and raya ( Brassica juncea L. Czern) straw containing 53.3 and 136.7 μg Se g −1, respectively. Each of the fodder crops was grown after incorporation of Se-rich materials either individually or in a sequence – sorghum–maize–berseem by incorporating Se-rich straws only to the first crop. Application of Se-rich straws to each crop, even at the greatest rate of 1%, did not have any detrimental effect on dry matter yield of different crops. With increase in the level of wheat straw from 0% to 1%, Se content in sorghum and maize plants increased to greatest level of 1.3 and 1.5 μg g −1, respectively, at 0.3% of applied straw and thereafter it decreased consistently. In case of raya straw, the greatest Se content in sorghum (2.3 μg g −1) and maize (3.0 μg g −1) was recorded at 0.3% and 0.4% of the applied straw, respectively. Unlike sorghum and maize fodders, Se content in all the four cuts of berseem continued to increase with increase in the level of applied straws and for different cuts of berseem it varied from 1.6 to 2.3 and 3.4 to 4.3 μg g −1 in case of wheat and raya straw, respectively. Similar variations in Se content of different fodder crops were recorded when these were grown in the sequence – sorghum–maize–berseem; but Se content was 2–4 times lower than when each crop was grown with fresh application of Se-rich straw. None of the fodders absorbed Se in levels toxic for animal consumption (>5 μg g −1) even at the greatest level of applied straw. Of the total Se added through Se-rich straws, utilization of Se was not more than 2% in case of sorghum and maize crops and up to 5% in case of berseem. At the time of sowing of sorghum, hot water soluble Se (HWS-Se) in soils treated with different levels of Se-rich wheat and raya straw, respectively, varied from 18 to 36 and 18 to 79 μg kg −1. Whereas in case of berseem, it varied from 33 to 101 and 33 to 154 μg kg −1, respectively. HWS-Se present at the sowing time of berseem was significantly correlated with Se content of all the four cuts in the soil treated with Se-rich straws; the coefficients of correlation ‘ r’ varied between 0.79 ( p ⩽ 0.05) and 0.99 ( p ⩽ 0.001). Selenium-rich materials supplied significant amounts of S, P