Abstract

                                A three year field experiment was conducted during September-March of 2010-2011 and 2012-2013 at Agricultural College and Research Institute, Killikulam to study the influence of humic acid with graded levels of inorganic fertilizers on productivity, nutrient uptake, economic and soil fertility of brinjal var KKM1. The experiment was carried out in Randomized Block Design (RBD) replicated thrice with 11 treatments. The humic acid was applied through soil and foliar spray with 75 % RDF (N75 P37.5 K22.5). Application of 75 % RDF (N75 P37.5 K22.5) + 10 kg HA (SA) + 0.2% HA (FS) /ha produced significantly higher plant hight (112.0 cm), days to 50 % flowering ( 56.4),number of branches plant-1 (9.4), number of fruits plant-1 (25.3 ), single fruit weight ( 69.9 g), fruit yield (33.4 t ha-1), total dry matter production (10.08 t ha1), net return ( 1,33,131 ha-1) and BC ratio (4.29), N, P and K uptake (143.1, 33.3 and 148.6 kg ha-1, respectively) compared to control. However, 75 % RDF (N75 P37.5 K22.5) + 10 kg HA (SA) + 0.1% HA (FS) ha-1 showed higher plant height, number of branches, days to 50 % flowering, number of fruits per plant, single fruit weight, fruit yield, total dry matter production, net return, BC ratio, N,P and K uptake. Significant built up of organic carbon (0.92 %), available N (291.5 kg ha-1), available P (25.4 kg ha- 1) and available K (293.7 kg ha-1) was registered with 75 % RDF + 10 kg HA (SA) + 0.2% HA (FS) ha-1.

Key words : Alfisol, Available nutrients, Brinjal fruit yield, Economics, Humic acid, Nutrient content and uptake