Identification and Validation of Pedochemical and Fertility Indices of Soils Influencing Maize (Zea mays) Crop Production in the Rain Forest Agro-ecology of Nigeria

Abstract

Background: The soil is a fundamental natural resource of any nation hence proper assessment of the kind and extent of this resource is prerequisite to its improvement and rational use. Method: Random sampling technique was used to collect soils from each of the 18 LGAs of Cross River State, Nigeria and each separated into two parts. One part was used for the cultivation of local maize while the other part of soil was analysed for pedochemical properties and fertility indices. Result: The results reveal that organic carbon ranged from 1.40 g/kg3 to 2.84 g/kg3. Available Phosphorus varied from 3.31 mg/kg to 29.24 mg/kg. The value of total nitrogen varied from 0.11 g/kg3 to 0.24 g/kg3. Cation exchange capacity (CEC) also varied from 7.01 Cmol/kg3 to 12.01 Cmol/kg3. The soils across the agroecology were more acidic 5.00 to less acidic 0.61. Boron varied from 0.52 mg/kg3 to 2.01 mg/kg3 while Zinc also ranged from 1.93 mg/kg3 to 5.0 mg/kg3. The results also show that 33.33% of the soils were rated high, medium and low for available phosphorus. It was identified that total nitrogen nutrient fertility ratings for the soils was 77.78% high fertility ratings and 22.22% medium fertility ratings. Results identified organic carbon fertility rating was of high fertility rating of 72.23% while 27.67% medium rating was identified for organic carbon content. Ten (10) principal components (PC) were identified to contribute to the total 100% support for maize crop production in the study area.