In spite of the leading position of the agrarian Bida suburbs in north-central Nigeria in the practice of the
sawah system of rice production in Nigeria, there is no information in the literature regarding the chemical properties and fertility status of the paddy fields. In the present study, the topsoil properties of representative inland valleys for
sawah rice culture were examined at four locations (Gadza, Nasarafu,
Shaba
-Maliki and Ejeti) in the area. Apart from Ejeti where the soil is a clay loam, the predominant texture is sandy loam. The parent materials are young, with a low weathering potential, as expected in soils with a high silt:clay ratio. The soil reaction was strongly to moderately acidic in water (pH range, 4.5-5.3). Values were generally low for the soil organic carbon concentration (range, 4.6-12.5 g kg
-1) and total nitrogen content (0.42-0.98 g kg
-1), while available phosphorus content indicated moderate values (11.5-26.0 mg kg
-1). The ranges of values for the total exchangeable bases and acidity were, respectively, 2.04-4.62 and 1.1-2.7 cmol kg
-1. The differences between effective and normalized cation exchange capacity (CEC) were somewhat wide and, consequently, the derived base saturation showed high (60.1%) and low (35.9%) mean values, respectively. Among the locations, Ejeti showed the most suitable values for almost all these parameters. The silt and clay fractions and the organic carbon concentration showed significant positive relationships with the effective CEC, implying that these parameters controlled the fertility of the inland-valley soils. Management strategies for coping with the low pH as well as the low organic carbon, total nitrogen and basic cations’ contents in the soils are suggested.
抄録全体を表示