Economic Performance and Investment Recovery of Conventional, Container Gardening, Kratky, and Nutrient Film Technique Systems for Lettuce (Lactuca sativa L. cv. Olmetie RZ 1000 Batavia) Production under Tropical Conditions
Danny E. Carabio *
College of Agriculture, Food Science, Agribusiness, and Development Communication, Cebu Technological University, Barili Campus, Cagay, Barili, Cebu 6036, Philippines.
*Author to whom correspondence should be addressed.
Abstract
Lettuce production under tropical conditions is constrained by high temperatures, water requirements, and variability in resource availability, which can affect crop productivity and production costs. Conventional, container-based, and hydroponic systems differ considerably in their requirements for water, energy, infrastructure, and capital investment. However, direct comparisons of their economic performance and investment recovery under a common tropical production setting remain limited, creating a need to evaluate productivity alongside resource use and financial outcomes. This study evaluated the economic performance and investment recovery of four lettuce (Lactuca sativa L. cv. ‘Olmetie RZ 1000 Batavia’) production systems—conventional open-field farming, container gardening, Kratky hydroponics, and Nutrient Film Technique (NFT)—under tropical conditions. A randomised complete block design with four treatments and three replications was used, with a 28-day production cycle. Fresh biomass, measured water use, electricity requirement, production cost, gross income, first-cycle net income, ROI, and investment recovery were evaluated. NFT produced the highest fresh biomass (133.04 g plant⁻¹), followed by container gardening (74.77 g plant⁻¹), Kratky (58.17 g plant⁻¹), and conventional farming (31.60 g plant⁻¹). The two soil-based systems used 56.00 L plant⁻¹, compared with 2.00 L for Kratky and 2.08 L for NFT. The electricity cost for NFT was approximately ₱2.99 plant⁻¹. At a selling price of ₱350 kg⁻¹, gross income ranged from ₱11.06 plant⁻¹ in conventional production to ₱46.56 plant⁻¹ in NFT. All systems had negative first-cycle net income because the complete unit cost basis was charged against the first harvest. Using the study-specific gross-revenue capital-recovery indicator, investment recovery ranged from 1.14 cycles for container gardening to 5.87 cycles for NFT. The results demonstrate that higher biomass and water efficiency can coexist with substantially higher capital requirements, making economic evaluation essential when selecting lettuce production technologies.
Keywords: Lettuce production, hydroponics, Kratky method, nutrient film technique, economic performance, investment recovery, capital budgeting