S. Ramesh, S. Keerthana, P. Sudhakar, S. Manimaran1 and K. Arivukkarasu
Abstract
Field experiment was carried out at the Experimental farm, Annamalai University, Annamalai Nagar to study the productivity, economic efficiency and agronomic efficiency of traditional rice varieties as influenced by EM compost and fertilizer nitrogen under Cauvery delta zone of Tamil Nadu (2018). The experiment conducted in split-plot design and treatments were replicated thrice, the three traditional rice varieties were assigned as main plot treatments viz., Mapillai samba, Illupai poo samba and Seeraga samba, and integrated nutrient management were assigned as sub plot treatments, it includes control, graded dose of nitrogen alone ant it combination with FYM, EM (effective microorganisms) compost, pressmud, green manure. From the results of field study, among the rice varieties, Mapillai samba significantly recorded higher grain yield of 2574 kg ha-1, straw yield of 3831 kg ha-1 and harvest index of 39.85 and nitrogen use efficiency of 36.58 (NUE) agronomic efficiency of 21.68 (AE) and apparent N recovery (%) of 56.93 (ANR). The aforesaid parameters were least under Illupai poo samba rice variety. In respect of INM treatments, plots received with 75% RDN along with EM compost @ 5 t ha-1 significantly recorded maximum grain yield of 2967 kg ha-1, straw yield of 4341 kg ha-1 and harvest index of 40.56. Also the same treatment recorded higher values of nitrogen use efficiency of 39.56 (NUE), agronomic efficiency of 25.58 (AE) and apparent N recovery (%) of 66.44 (ANR). The lowest grain yield, straw yield and harvest index of rice were registered under control. But lowest values of nitrogen use efficiency (NUE), agronomic efficiency (AE) and apparent N recovery (%) (ANR) were recorded under 100% recommended dose of nitrogen (RDN). In respect of economics, among the treatment combination seeraga samba rice variety received with 75% RDN + EM compost @ 5 t ha-1 registered higher gross return, net return and return per rupee invested.