Suitability Evaluation of Wetland Soils for Tomato Production in Okobo, South-South Nigeria

Abstract

This study assessed the suitability of selected wetland soils in Okobo, Akwa Ibom State, Nigeria, for tomato production based on their physicochemical properties. Tomato is an important vegetable crop widely consumed in the diets of people in Akwa Ibom State; however, limited studies have examined the suitability of Okobo wetland soils for its cultivation. To address this gap, two soil profile pits were excavated in two different communities and designated as Pedon 1 and Pedon 2. Soil samples collected from the profiles were analyzed to determine their physical and chemical characteristics and to evaluate their suitability for tomato production. The soil colour in Pedon 1 ranged from black (7.5YR 2/1) to dark yellowish brown (10YR 4/6), while Pedon 2 ranged from dark reddish brown to dark greyish brown (10YR 4/2). The textural class varied from loamy sand to sandy loam in Pedon 1 and from sandy loam to loamy sand in Pedon 2. Organic carbon values ranged from 1.60–2.40 g/kg in Pedon 1 with a mean of 2.0 g/kg, while Pedon 2 ranged from 2.2–2.8 g/kg with a mean of 2.5 g/kg, indicating generally low organic carbon content in both pedons. Available phosphorus had a mean value of 4.45 mg/kg in Pedon 1 and 5.20 mg/kg in Pedon 2, suggesting low phosphorus availability. Soil reaction showed that the soils were acidic, with mean pH values of 5.0 in Pedon 1 and 6.25 in Pedon 2. Exchangeable bases (Ca, Mg, Na, and K) were also found to be low in both pedons. Based on the land suitability evaluation, the soils met some of the basic environmental requirements for tomato cultivation, such as appropriate texture and humid conditions; however, fertility limitations were observed. The soils were classified as marginally suitable (S3f) due to low nutrient status, particularly phosphorus deficiency. The study therefore recommends the application of both organic and inorganic fertilizers to improve soil fertility. Amendments such as bone meal, a natural fertilizer rich in phosphorus, are suggested to enhance nutrient availability, promote root development, and improve flowering and fruiting of tomato plants. These improvements would enhance the productivity of tomato cultivation in the wetland soils of Okobo.