Among salad crops, lettuce (Lactuca sativa L.) is the most widely used and takes up the greatest space worldwide. It is a member of Asteraceae, the biggest dicotyledonous family (formerly Compositae). It is a tall, milky-juiced annual leafy herb. Early in the season, it grows a short stem and a cluster of leaves that, depending on the variety, vary greatly in shape, character, and color. It is widely acknowledged that Europe and Asia are where it first appeared in the New World (Masarirambi et al. 2012). It was brought to several nations, including America, Europe, China, and others, shortly after the New World was discovered. Eventually, it spread to the rest of the world. China is currently the world’s top producer of lettuce, with the United States coming in second. It is frequently eaten either by itself or with dressing and is typically used as a salad with tomatoes, carrots, cucumbers, or other salad vegetables. Among the main vegetables, lettuce stands out since it is consumed almost exclusively raw (Snowdon 2001). Although it cannot be considered a major salad crop, it has become one of the most significant and popular salad crops in Bangladesh because of its many uses, nutritional value, and delicious flavor. Although lettuce is becoming more and more popular, Bangladeshi farmers are not well-informed on its production package. For growth and development, this vegetable needs a lot of nitrogenous fertilizer. However, using too much nitrogen fertilizer to boost crop output affects the soil’s nutritional balance, pollutes the soil, lowers crop quality, and may render a significant portion of the resources unusable (Ahmed et al. 2022). In order to achieve a greater vegetable output, soil health is essential (Nahar et al. 2021; Jannat et al. 2023). Comparative studies show a consistent but nuanced story about how lettuce responds to organic and conventional fertilization. Under controlled conditions, conventional mineral fertilizers rapidly increased soil nitrogen and phosphorus availability, resulting in higher chlorophyll content, stronger canopy development, and greater fresh biomass, while organic amendments such as compost acted more slowly and produced lower short-term yields despite improving soil organic matter and amino acid accumulation (García-Rández et al. 2025). However, evidence also shows that when organic fertilization is carefully managed, especially in combination with biostimulants, it can significantly enhance lettuce morphology and yield, increase head mass and leaf number while also promoting beneficial secondary metabolites related to stress tolerance (Fajdetić et al. 2025). Over the long term, field-based comparisons further indicate that organically managed systems can sometimes match or even surpass conventional yields, with organically grown lettuce showing higher fresh weight in certain trials, highlighting the importance of management practices and time scale when evaluating productivity and profitability (Dhakal and Nandwani 2022). Concerns over the long-term sustainability of crop production have grown as evidence shows that excessive use of chemical fertilizers can degrade soil health and threaten sustainable productivity (Virgine Tenshia and Singram 2005). At the same time, consumers increasingly associate organic farming with higher produce quality, driving demand for vegetables grown with fewer or no synthetic inputs. In response to the environmental and health risks linked to chemical fertilizers, many farmers are shifting toward vegetable production systems that avoid inorganic fertilizers altogether (Asaduzzaman et al. 2010; Chowhan 2021a). As a result, organic farming has emerged as a widely accepted alternative for reducing health risks while supporting more sustainable agricultural practices.

The lettuce is perfectly suited to Bangladesh’s Rabi season. In comparison to other nations that cultivate lettuce, such as Italy (73.5 t ha^-1), Japan (58.6 t ha^-1), and India (108.9 t ha^-1), this country’s lettuce farming is restricted to a very small area with minimal production and an average yield of only 4.0 t ha^-1 (FAOSTAT 2025). Lack of knowledge about contemporary production techniques, such as appropriate genotypes, ideal planting times, fertilizer requirements, soil fertility status, etc., may be the primary cause of this country’s poor lettuce yield (Chowhan 2016; Chowhan 2021b). In the context of the aforementioned facts, the current study was conducted to examine the vegetative development, yield, and economic suitability of lettuce cultivars under conventional and organic fertilization, as well as to determine the optimal combinations for long-term crop productivity.

The experiment was conducted at the Horticulture Research Farm of Gazipur Agricultural University (GAU), Salna, Gazipur during the winter season. The cultivar of lettuce used in this experiment was the Green Wave, Grand Rapids and Iceberg were collected from the market of Siddique Bazar of Dhaka. The experiment comprised of six treatments (T₁ = Green Wave × Organic, T₂ = Grand Rapids × Organic, T₃ = Iceberg × Organic, T₄ = Green Wave × Conventional, T₅ = Grand Rapids × Conventional, T₆ = Iceberg × Conventional). In the organic fertilization method only well decomposed cow dung at the rate of 50 t ha^-1 was applied and in the conventional fertilization method- Urea, TSP, MOP and well decomposed cow dung was applied at the rate of 250 kg ha^-1, 150 kg ha^-1, 200 kg ha^-1 and 15 t ha^-1 respectively (Moniruzzaman 2002). Urea was used as a top dressing in two equal installments at 12 and 24 days after transplanting (DAT) in the case of the conventional growth method. Only well-decomposed cow manure (50 t ha^-1) was used in the organic growth approach. The GAU meteorological station provided the distribution of average monthly maximum and minimum temperatures, relative humidity, and rainfall during the crop growing season, which is shown in Suppl. material 1: table SS1. Three replications of the field experiment were carried out using Randomized Complete Block Design (RCBD). The experimental plot was 108 m² in total, measuring 13.5 m in length and 8 m in width. Three equal blocks were created from the entire region. Each block was split up into six plots, each with a random distribution of six treatment combinations. The experiment included a total of eighteen-unit plots. Each plot was 2 m by 1.5 m. Two blocks and two plots were kept 70 cm and 50 cm apart, respectively. Plots were elevated to a height of 10 cm. Row to row and plant to plant spacing in the plot was maintained at 25 cm and 40 cm, respectively. Intercultural tasks like irrigation, mulching, and gap filling were carried out as needed. With the exception of yields, which were recorded plot-wise, ten plants were chosen at random from the middle rows of the unit plot to avoid the border effect. To evaluate plant development, yield characteristics, and yields as impacted by various treatment combinations, data on a variety of parameters were gathered. At 15, 25, and 35 days after transplanting (DAT), data were gathered on plant height, leaf length, leaf breadth, number of leaves per plant, and total leaf area per plant. Total yield (t ha^-1), leaf yield per plant (kg), and leaf yield per plot (kg) were determined and calculated at final harvest. The “Statistix 10” program was used to statistically analyze the gathered data (Statistix 2021). The Tukey’s Honest Significant Difference (HSD at 5%) was used to examine the mean differences between the treatments after calculating the mean values for each treatment and conducting an analysis of variance for each variable (Gomez and Gomez 1984). Economic analysis was done in order to compare the profitability of the treatment combination. Values of Gross return, Net return and Benefit-Cost Ratio (BCR) were calculated in accordance with the formula by Chowhan et al. 2021, 2022a. The details of Cost of production (Input cost) and Overhead costings are described in Suppl. material 1: tables S2, S3.

Assessment of the growth patterns revealed distinct differences in leaf development and biomass accumulation across the genotypes. Table 1 provides a comprehensive overview of the descriptive statistics for these leaf-related traits and final yield attributes.

The above finding makes it clear that larger levels of organic fertilizers, especially well-decomposed cow dung, have a positive impact on lettuce plant height at harvest. Throughout the growing phase, organic fertilizers could have accelerated the nitrogen mineralization process and ensured the slow but consistent release of vital nutrients, which may have raised the synthesis of carbohydrates, improved growth, and ultimately increased the height of the plant at harvest. Islam et al. (2012) discovered that environmentally friendly organic fertilizer improved lettuce growth and yield, after using synthetic fertilizers and a control. The superior performance of Iceberg lettuce in terms of yield under conventional fertilization aligns with earlier reports indicating that crisphead lettuce types respond strongly to readily available nitrogen sources (Polat et al. 2008; Masarirambi et al. 2012). Conventional fertilizers provide immediate nutrient availability, which enhances vegetative growth and biomass accumulation. In contrast, organic fertilization improved plant height and sustained leaf growth, particularly in Green Wave, suggesting a gradual nutrient release pattern that supports steady growth (Chowdhury and Rahman 2021). Similar findings were reported by Islam et al. (2012) and Asaduzzaman et al. (2010), who noted improved soil structure and microbial activity under organic amendments. The economic superiority of organic Iceberg lettuce reflects increasing consumer willingness to pay higher prices for organically produced vegetables. Studies by Reganold and Wachter (2016) and Seufert et al. (2012) also emphasized that organic systems, despite slightly lower yields, can remain profitable due to reduced external inputs and price premiums. Overall, the interaction between cultivar genetics and nutrient management practices plays a crucial role in determining lettuce productivity and profitability (Chowhan et al. 2022b). Selecting appropriate cultivars for specific fertilization systems is therefore essential for sustainable vegetable production (Al-Fuad et al. 2025).

The study demonstrates that lettuce growth, yield and profitability are significantly influenced by the interaction between cultivar and fertilization method. Iceberg emerged as the most productive cultivar under both fertilization systems, achieving maximum yield under conventional fertilization and highest economic return under organic management. Considering yield stability, profitability and consumer preference for organic produce, organic cultivation of Iceberg lettuce appears to be a sustainable and economically viable option for farmers in Bangladesh. Adoption of suitable cultivar–fertilization combinations can substantially improve lettuce productivity and farm income while supporting environmentally friendly agricultural practices.

Conceptualization: NA. Investigation and Validation: NA, MNN and MSR. Data curation: SC. Formal analysis: NA. Editing, final draft preparation and revision: SC. Supervision: EK, MSA and MSR.

The authors accept full responsibility for the content of the manuscript, including the disclosure of any use of AI.

Artificial intelligence tools were used solely for language editing, including grammar and error checking. All content was reviewed by the authors, and only relevant and verified information was retained.