Nutrient management for yield improvement of transplanted rice in the southern region of Kerala

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.