Quality and fertility status of soils in the groundnuts (Arachis hypogaea L.) production basin of Ngong, North Cameroon

Abstract

Ngong is a famous groundnut (Arachis hypogaea L.) producing locality in Cameroon, contributing to the supply of local markets and neighboring countries. Official figures showed gradual yield decrease over recent years, attributable to various factors, with poor soil conditions among the most acute. However, missing information on soil quality and fertility status in these areas is jeopardizing efforts of improving agricultural productivity. This study aimed to assess the soil fertility status in the groundnut production basin of Ngong. Three main ground-nut production areas (Douka-longo, Tamoundé1, and Sabongari) of the basin were selected and twenty-three topsoil samples (0 – 30 cm) collected. Soil fertility attributes (index of structural stability (ISS), index of soil sealing (IB), Forestier index (IF), aluminium toxicity (m) and Soil Quality Index (SQI)) were assessed. The studied sites were effectively poor in soil fertility, having very low values of N, P, K, S, and cation exchange capacity (CEC). These soils are under high risk of degradation because of the low soil aggregate stability (ISS < 9%) and fertility (IF < 1.5) indexes. The SQI ranged from 0 to 0.4 indicative of poor fertility with degraded soil condition. The main factors controlling soil quality include Ca, pH, organic matter (OM), available P, total Nitrogen and CEC. Long-term maintenance of soil quality requires better integrated soil fertility management practices. Optimal soil nutrients management system such as the application of organo-mineral amendments rich in N P, K, Ca and Mg to promote plant root establishment, which will also improve the soil structure should be considered to enhance the soil fertility status along with the inclusion of good cultivars for yield improvement.

Keywords

• soil fertility
• soil quality
• soil indicators
• ngong
• groundnut production