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 g...