Response of rice to applied sulphur

Abstract

Experiments were conducted at the Agricultural Research Station, Mannuthy and the Radiotracer Laboratory of the Kerala Agricultural University during the first crop season of 1988 to study the response of rice to applied sulphur and the relative uptake and distribution of soil and fertilizer sulphur. There was a field experiment conducted with four levels of sulphur (0, 20, 40 and 60 kg ha-1) and four sources of sulphur (ammonium sulphate basal dressing, ammonium sulphate-top dressing, ammonium phosphate sulphate and elemental sulphur). The experiment was laid out in RBD in plots of size 4.6 m x 4.5 m and replicated thrice. A pot culture experiment was conducted for studying the uptake and distribution of 35 applied as albelled (MH4) 2 SO 4 at 20, 40 and 60 kg ha-1 levels of sulphur application. The utilization of sulphur applied at planting and that applied at panicle initiation were also studied in this experiment. The results showed that plant height and number of tillers were not significantly influenced by the levels of sulphur, sources of sulphur and their interactions. The leaf area index increased due to the application of sulphur at all the growth stages. The dry matter production increased with sulphur application. The increase in dry matter production due to the application of graded levels of sulphur was found to vary from 4 to 47 per cent.