Performance of Sorghum Grown on a Salt Affected Soil Manured with Dhaincha Plant Residues Using a ¹⁵N Isotopic Dilution Technique

ABSTRACT

A field experiment was conducted on a salt-affected soil to determine the effect of application of three types of Dhaincha (Sesbania aculeata Pers.) residues (R, roots; L, shoots; L+R, shoots plus roots) on the performance of sorghum (Sorghum bicolor L.) using the indirect ¹⁵N isotopic dilution technique. Results indicated that sesbania residues (L and L+R), used as green manures, significantly increased grain yield, dry matter production, N uptake, and water use efficiency of sorghum. Percentages of nitrogen (N) derived from residues (%Ndfr) in sorghum ranged from 6.4% to 28%. The N recoveries in sorghum were 52%, 19.6% and 19.7% of the total amount contained in sesbania roots, shoots and roots plus shoots, respectively. The beneficial effects of sesbania residues are attributed not only to the additional N availability to the plants, but also to effects on the enhancement of soil N uptake, particularly in the L+R treatment. The findings suggest that the use of Sesbania aculeata residues, as a green manure, can provide a substantial portion of total N in sorghum. In addition, the use of sesbania green manure in salt-affected soils, as a bio-reclaiming material, can be a promising approach for enhancing plant growth on a sustainable basis.

Keywords:

• Sesbania aculeata
• Sorghum bicolor
• green manure
• ¹⁵N

ACKNOWLEDGMENTS

We would like to thank Professor I. Othman, General Director of AECS, for his support. The technical assistance of the staff at the AECS Department of Agriculture is greatly acknowledged.

Notes

^a Means, within a column, followed by the same letter are not significantly different (P > 0.05).

^a Means, within a column, followed by the same letter are not significantly different (P > 0.05).

^a Means within a column followed by the same small letter are not significantly different (P > 0.05).

^a Means within a column followed by the same letter are not significantly different (P > 0.05).