Effect of Salinity on the Foliar Nutrient Yield and Proximate Composition of Okra, Abelmoschus esculentus (L.) Moench Planted in Gliricidia sepium (Jacq.) Leaves Ameliorated Soil

Abstract

Aims: This field study evaluates the effect of salinity on the foliar nutrient and proximate composition of Okra planted in Gliricidia sepium leaf ameliorated soil. Study Design: The experiment was laid out in a completely randomized design (CRD) and replicated three times. It comprised of: Treatment                                              Levels Salinity                                     4 (0, 75, 100, 150mM) G.sepium amelioration               2 (Applied and Not Applied) Place and Duration of Study: This study was carried out in the Department of Botany and Ecological studies Nursery Garden, University of Uyo, Akwa Ibom state between September 2023 and February, 2024. Methodology: Ninety-Six black perforated nursery bags (24cm x 33cm) were each filled with 10kg sieved top (0-20cm) sandy loam soil. The filled bags were randomly divided into 2 groups of 48 each and designated G. sepium leaves ameliorated and non- G. sepium ameliorated. Each batch of 48 was then randomly divided into 4 groups of 12 each for the different salinity treatments. Results: The results showed that amelioration of salt stress soil with Gliricidia sepium leaves in all cases increased the foliar nutrient yield of Okra. Proximate analysis showed that Crude protein was highest in plants grown in Gliricidia sepium leaves ameliorated soil without salt stress (22.3%) but lowest in plants grown in 150mM NaCl stressed soil without Gliricidia sepium leaves (15.10%). Carbohydrate on the other hand was highest in plants planted in 150mM NaCl stressed soil ameliorated with Gliricidia sepium leaves (62.22%). Foliar nutrients yield analysis showed that N, P, K, Ca, Mg and Fe were highest in plants grown in Gliricidia sepium leaves ameliorated soil without salt stress (0.11, 1.88, 2.41, 4.03, 2.63, 0.22 mg g-1) respectively, but lowest in 150mM NaCl stressed soil without Gliricidia sepium leaves (0.07, 1.20, 1.43, 3.36, 1.88, 0.17mg g-1). Conclusion: This study demonstrates that Gliricidia sepium leaf amendment can effectively reduce the negative effects of salinity on okra growth, yield, and nutrient composition. By improving crude protein content and essential foliar nutrients even under salt stress, the study provides an affordable, eco-friendly strategy for enhancing soil fertility and crop productivity in saline-prone areas.