Effect of fish waste hydrolysate on the cultivation of lettuce (Lactuca sativa) in Tacna, Peru

Abstract

Lettuce (Lactuca sativa) is a widely cultivated and consumed vegetable globally due to its rapid growth and high nutritional value. However, intensive production has led to an excessive reliance on synthetic fertilizers. In response, biostimulants, particularly those derived from organic waste such as fish hydrolysates, have emerged as a sustainable alternative. This study evaluated the effect of fish waste hydrolysate as a biostimulant on curly lettuce (Lactuca sativa, Green Span variety) cultivation in Tacna, Peru. A completely randomized block design (CRBD) was implemented with four treatments (200, 400, 600, and 800 L ha⁻¹) and three replicates. Yield was assessed based on individual plant weight, analyzed using ANOVA and Tukey’s test (p < 0.05). The results indicated that the 600               L ha⁻¹ treatment achieved the highest yield (300.26 g per plant), demonstrating a positive effect on biomass accumulation. However, the 800 L ha⁻¹ treatment did not yield additional improvements and suggested potential negative effects due to nutrient saturation. A regression analysis determined that the optimal dose for maximizing individual plant yield was 670.74 L ha⁻¹, with a projected weight of 306.61 g per plant. Nevertheless, no significant differences in total yield per hectare were observed among treatments, indicating that while the hydrolysate enhances individual plant growth, it does not necessarily increase overall production. The study concludes that fish hydrolysate is a promising tool for improving lettuce productivity under challenging conditions, though its effectiveness depends on additional influencing factors.