Soil Fertility Capability Evaluation along River Kaduna Watershed, Northern Nigeria

Abstract

This study was conducted along the Kaduna River watershed with the goal of evaluating the fertility potential of the watershed soils. Six profile pits in all were excavated and described. The parameters used in the study to evaluate fertility capabilities were condition modifiers, substrata type, and type. The silt clay loam soil texture class dominated the examined soils. The textures of nearly all of the investigated soils (pits 1, 2, 3, 5, and 6) ranged from silt clay loam at the top horizons to silty loam or silt clay down the horizons. The only exception was Pit 4, where silty loam was predominant at both the top and sub layers. The pH of the soil was mostly neutral (pH > 5.0 <6.0), with Pit 4 being the lone exception. Pit 4's pH was higher (pH = 4.92) in terms of CaCl2. All tested areas, with the exception of Pit 1, had a limitation of dryness (d) according to condition modifier classification, indicating a situation in which soils experience dryness > 60 consecutive days/year within 20 cm to 60 cm depth. With the exception of Pit 4, all other examined soils had Effective Cation Exchange Capacity (ECEC) values greater than 6 Cmolkg – 1 soil below, indicating significant exchangeable cation leaching. One of the main problems with the investigated soils was their low nutritional reserve (exchangeable K < 0.20 c mole kg -1 soil). Fertility Capability Classification placed Pit 1 as LCgv; Pit 2 Ldkv; Ldk in Pits 3, 5 and 6 and Ldek in Pit 4. Application of organic compounds rich in exchangeable basic cations especially K should be practiced by farmers near river Kaduna watershed. Also, the usage of river Kaduna for irrigation purposes should be increased to enhance dry season farming since rainfall duration is short in North Western Nigeria.