Abstract:
An experiment entitled "Nutrient management for yield
improvement of transplanted rice (Oryza sativa L.) in the southern region of Kerala"
was conducted at Cropping Systems Research Centre (CSRC) Karamana, during
the kharif season of 1998 to study the efficacy of organic manures in conjunction
with varying levels of NPK nutrients and sulphur in enhancing rice yield using the
variety Kanchana.
The experiment was laid out in 33 partially confounded factorial
RBD with two replications. Combinations of three levels each of organic manures
(M), inorganic NPK fertilizers (F) and sulphur (S) constituted the treatments. FYM
@ 5 and lOt ha-l as well as vermicompost @ 5 t ha-l included the different
manure levels. The normal NPK rates of 70 : 35 : 35 kg ha-l and enhanced rates of
87.5 : 43.75 : 43.75 and 105 : 52.5 : 52.5 kg ha-l were the three fertilizer levels.
The different S levels were no sulphur, S @ 12.5 and 25 kg ha-1 Higher order
interactions of MFS and M2FS were confounded in Rep I and Rep 11 respectively.
Results of the field experiment revealed that the main effects of
organic manures, chemical fertilizers and sulphur as well as their combinations
exerted significant positive influence on most of the growth and yield attributing
characters of rice. The higher NPK levels upto 105 : 52.5 : 52.5 kg ha-l and S
levels of 25 kg ha-l were found significantly superior to lower levels. Organic
manuring with FYM @ 10 t ha-1 and vermicompost @ 5 t ha-1 were found to be
equally good in influencing growth and yield of rice.
The available NPK status of soil after the experiment was
maintained well above the initial status. The available sulphur status of soil was
found to be considerably reduced in treatments which didn't receive sulphur
addition.
FYM levels recorded better benefit : cost ratio over verrnicompost
addition. Increase in NPK levels upto 105 : 52.5 52.5 kg ha-l and sulphur
addition @ 12.5 kg ha-l was found profitable. The combination of 5 t ha-l FYM
along with the highest NPK level of 105 : 52.5 : 52.5 kg ha-I and S @ 25 kg ha-I
recorded the highest B : C ratio, but this was comparable to that obtained with the
combined effect of 5 t ha-l FYM, NPK @ 87.5 : 43.75 : 43.75 and S @ 12.5
kg ha-I.
