Use of Banana Rachis Leachate as Fertilizer Characterization and Effects on Soil and Crops

Aims: Banana (Musa paradisiaca) cultivation plays a significant role in Argentina's regional economies, generating substantial crop residues, including the rachis of the infructescence. The production of leachates from rachis presents an opportunity to enhance sustainability in agricultural systems. Study Design: This study aimed to characterize the physicochemical properties of banana rachis leachate produced under controlled conditions in Formosa, Argentina, and evaluate its effects on a reference horticultural crop and its substrate. Place and Duration of Study: Agricultural Technology Validation Center (ATVC) Misión Tacaaglé, Formosa, Argentina; between 2021 and 2023. Methodology: Leachate production followed a standardized protocol, including (i) identification of the fruit’s origin, (ii) processing of freshly cut rachis into sections and (iii) placement of the rachis pieces into a leaching pool equipped with a drainage system. The leachate exhibited high potassium (4,871.9 mg L⁻¹), alkaline pH (8.2) and high electric conductivity (18.9 dS.m⁻¹,) too. The total nitrogen and phosphorus contents were respectively 392.0 mg.L⁻¹ and 124 mg.L⁻¹. A pot trial with lettuce (Lactuca sativa) was conducted on which the evaluated leachate was applied. The treatments were T1 (Control, whit no fertilization), T2 (Urea application), T3 (Leachate application) and T4 (Combined application, leachate and urea). Results: Leachate applications (T3 and T4) had no negative impact on plant survival, whereas T2 (urea-only treatment) caused a 33.33% mortality rate. T3 significantly enhanced lettuce growth, particularly in plant height and leaf number, while T4 did not differ significantly from the control. T3 had no adverse effects on soil properties and increased K availability. In contrast, urea-containing treatments (T2 and T4) caused soil acidification and increased soluble salts, particularly Ca²⁺ and Mg²⁺, leading to decreased SAR values. Conclusion: The results suggest that leachates produced under controlled conditions can serve as a nutrient source, particularly potassium, for intensive crops. Further research is needed to refine application rates, methods, and their effects on different crops.