EFFECT OF ORGANIC AND MINERAL FERTILIZATION ON THE AGRONOMIC CHARACTERISTICS OF LETTUCE CULTIVATION

Abstract

Lettuce (Lactuca sativa L.) requires proper nutritional management to maximize yield and leaf quality. This study aimed to compare the biometric and yield development of looseleaf lettuce subjected to three fertilization managements: mineral (NPK 4-14-8 and 10-10-10), organic (cattle manure), and control (without fertilization). The experiment was conducted in Santa Mariana, Paraná, Brazil, evaluating 18 plants distributed across three individual beds (six plants per treatment). At 45 days after transplanting, shoot fresh weight, leaf number, head diameter, and plant height were measured. Mean shoot fresh weight values were 222.83 g per plant for the control, 280.17 g for organic fertilization, and 373.00 g for chemical fertilization. Descriptively, the mineral treatment showed the highest means, followed by organic fertilization and control. Organic fertilization stood out for enhancing soil water retention capacity, despite requiring greater control of weed species. However, due to the methodological limitations of a single-bed layout without random allocation or prior soil chemical analysis, it is not possible to safely isolate the fertilizer effect from local soil variations between beds. It is concluded that mineral fertilizer promoted greater descriptive growth under the tested conditions, highlighting the need for future studies with randomized block designs and independent replications to confirm trends.