Evaluation of Fertilizer-manure Blocks as a Slow Release Fertilizer Formulation for Okra [Abelmoschus esculentus (L.) Moench

Abstract

Background: Fertilizer use efficiency is the output of any crop per unit of the nutrient applied under a specified set of soil and climatic conditions and slow/ ccontrolled release fertilizer formulations offer agricultural producers the opportunity to increase fertilizer/nutrient use efficiency, especially in soils with very low cation exchange capacity. Methods: In pot culture study, fertilizer-manure blocks consisting of selected proportions of different organic manures and fertilizers were prepared in two dimensions (100 g and 25 g) with three different dosages of fertilizers (100% POP, 50% POP, 25% POP) and were evaluated in a pot culture experiment using Okra variety Arka Anamika. Result: Fertilizer-manure blocks showed significant effect on growth and yield of okra. The use of fertilizer-manure blocks of proportion; Coirpith-35%, Cowdung-25%, Vermicompost-13%, Groundnutcake-10%, Neem cake 10%, Zeolite-2%, Humic acid-5%, 100 g size containing 25% of the recommended dose of nutrients placed 5cm below the level of planting and top dressing of 50% of KAU POP recommendation was identified as the best treatment (B:C ratio-1.26 and nutrient use efficiency-28.12) for enhancing the productivity of okra in grow bags. Days to flowering, number of fruits per plant, fruit yield per plant, length of fruits, girth of fruits and number of seeds per fruit were significantly influenced by the treatments. The selected treatment had recorded highest value for number of fruits per plant (20.70), fruit yield per plant (457.9 g), fruit length(17.90 cm), fruit girth (6.326 cm) as well as number of seeds per fruit (58.67). The general application of the recommended fertilizers and soil test based recommendation were found to be on par with the placement of slow release fertilizer- manure blocks with respect to fruit yield per plant.