Performance of Groundnut (Arachis hypogaea L.) as Influenced by Integrated Nutrient Management Under Fertigation

Background: Groundnut (Arachs hypogeae) is a prominent legume vegetable oil seed crop in India and it’s lower productivity is a matter of concern attributed to the major constraints of inefficient irrigation and nutrient management in rabi season. Fertigation is the recent innovative gearing up technology in which the nutrients are applied in précised quantity along with drip irrigation at regular intervals throughout the crop growth matching with their requirement, resulting in enhanced resource use efficiency and crop yields. Liquid formulations of biofertilizers can be diluted sufficiently and applied through drip irrigation uniformly to the root zone of crop. Humic acid is widely used as fertilizer synergist and hence in combination with inorganic fertilizers can enhance their use efficiency and improve root zone activity. The present experiment was conducted to develop an integrated nutrient management practice in combination of chemical fertilizers with organic sources i.e., co inoculation of liquid biofertilisers and humic acid under fertigation for rabi groundnut under fertigation. Methods: The experiment was comprised of seven treatments of integrated nutrient management practices viz., T1- Soil application of 100% RDF(30-40-50 kg N,P2O5 and K2O haˉ¹) + Drip irrigation ; T2- 75 % RDF + Liquid biofertilizers @ 3.75 l haˉ1 ; T3- 75% RDF + Humic acid @ 12.5 l haˉ1 ; T4- 50 % RDF + Liquid biofertilizers @ 3.75 l haˉ1 ; T5–50 % RDF + Humic acid @ 12.5 l haˉ1 ; T6- 100 % RDF + Liquid biofertilizers @ 3.75 l haˉ1 ; T7- 100 % RDF+Humic acid @ 12.5 l haˉ1 which were laid out in randomised block design with three replications. Result: The integrated nutrient management practice with application of 100% RDF (30-40-50 kg N,P2O5 and K2O) + Liquid biofertilizers @ 3.75 l ha-1 (Rhizobium, Phosphorus solubilising bacteria and Potassium solubilising bacteria each @ 1.25 l ha-1) through fertigation recorded tallest plants (49.9 cm), highest LAI(2.05), SCMR value(34.5), highest number of nodules plant -1(60.2), pods plant-1(11.2), 100 pod weight(125.7 g), kernel weight (52.9 g) which resulted in the highest pod (3902 kg ha-1), kernel (2666 kg ha-1), haulm yied (4363kg ha-1 ), higher nutrient uptake and net returns (Rs.130818 ha-1) of groundnut, which were comparable to 100% RDF + Humic acid @ 12.5l ha-1 . However 75% RDF + Liquid biofertilizers @ 3.75 l ha-1 through fertigation recorded growth and pod yield (3988 kg ha-1) of groundnut on par with the best treatment of 100% RDF + Liquid biofertilizers @ 3.75 l ha-1 with a saving of 25 per cent of RDF and net returns of (Rs.130818 ha-1) and higher B:C ratio (2.31).